Posted on by Tammy Plotner

The Delphinus Constellation

This map shows Delphinus and Sagitta, both of which are near the bright star Altair at the bottom of the Summer Triangle. You can star hop from the Delphinus "diamond" to the star 29 Vulpecula and from there to the nova or center your binoculars between Eta Sagittae and 29 Vul. Stellarium

Welcome to another edition of Constellation Friday! Today, in honor of the late and great Tammy Plotner, we take a look at “the Dolphin” – the Delphinus constellation. Enjoy!

In the 2nd century CE, Greek-Egyptian astronomer Claudius Ptolemaeus (aka. Ptolemy) compiled a list of all the then-known 48 constellations. This treatise, known as the Almagest, would be used by medieval European and Islamic scholars for over a thousand years to come, effectively becoming astrological and astronomical canon until the early Modern Age.

One of these is the northern constellation of Delphinus, which translates to “the Dolphin” in Latin. This constellation is located close to the celestial equator and is bordered by Vulpecula, Sagitta, Aquila, Aquarius, Equuleus, and Pegasus. Today, Delphinus is one of the 88 modern constellations recognized by the International Astronomical Union (IAU).

Name and Meaning:

According to classical Greek mythology, Delphinus represented a Dolphin. Once you “see” Delphinus, it is not hard to picture a small dolphin leaping from the waters of the Milky Way. According to Greek legend, Poseidon wanted to marry Amphitrite, a Nereid – or sea nymph. However, she hid from him. Poseidon sent out searchers, one of whom was named Delphinus.

Delphinus is depicted on the left of this card from Urania’s Mirror (1825). Credit: Library of Congress/Sidney Hall

Can you guess who found Amphitrite and talked her into marrying? You got it. In gratitude, Poseidon placed Delphinus’ image among the stars. Not a bad call since the Nereids were known to live in the silvery caves of the deep and the silvery Milky Way is so nearby!

In the other version of the myth, it was Apollo – the god of poetry and music – who placed the dolphin among the constellations for saving the life of Arion, a famed poet and musician. Arion was born on the island of Lesbos and his skill with the lyre made him famous in the 7th century BC.

History of Observation:

The small constellation of Delphinus was one of the original 48 constellations complied by Ptolemy in the Almagest in the 2nd century CE. In Chinese astronomy, the stars of Delphinus are located within the Black Tortoise of the North (Bei Fang Xuán Wu) – one of the four symbols associated with the Chinese constellations. Delphinus was also recognized by some cultures in Polynesia – particularly the people of Pukapuka and the Tuamotu Islands.

Notable Objects:

Located very near the celestial equator, this kite-like asterism is comprised of 5 main stars and contains 19 stellar members with Bayer/Flamsteed designations. It’s primary star, Alpha Delphini (aka. Sualocin), is a multiple star system located 240 light years from Earth which consists of an aging subgiant of 2.82 Solar masses, and a companion that cannot be discerned because it is too close to its primary and too faint.

Next is Beta Delphini (aka. Rotanev), a pair of stars located approximately 101 light years from Earth. This system is comprised of a F5 III class blue-white giant and a F5 IV blue-white subgiant. If you don’t think astronomers have a sense of humor, then you better think again! Sualocin and Rotanev were both named by Italian astronomer Nicolaus Cacciatore, who simply spelled the Latin form of name (Nicolaus Venator) backwards as a practical joke!

Globular cluster NGC 6934. Credit: Hubble Space Telescope

Epsilon Delphini (aka. Deneb Dulfim) is a spectral class B6 III blue-white giant star located about 358 light years from Earth. It’s traditional name comes from the Arabic ðanab ad-dulf?n, meaning “tail of the Dolphin”.  Then there’s Rho Aquilae (aka. Tso Ke), a main sequence A2V white dwarf that is 154 light years distant. The star’s traditional name means “the left flag” in Mandarin, which refers to an asterism formed by Rho Aquilae and several stars in the constellation Sagittarius.

Delphinus is also home to numerous Deep Sky Objects, like the relatively large globular cluster NGC 6934. Located near Epsilon Delphini, this cluster is roughly 50,000 light years from Earth and was discovered by William Herschel on September 24th, 1785. Another globular cluster, known as NGC 7006, can be found near Gamma Delphini, roughly 137,000 light-years from Earth.

Delphinus is also home to the small planetary nebulas of NGC 6891 and NGC 6905 (the “Blue Flash Nebula”). Whereas the former is located near Rho Aquilae about 7,200 light years from Earth, the more notable Blue Flash Nebula (named because of its blue coloring) is located between 5,545 and 7,500 light-years from Earth.

Finding Delphinus:

Delphinus is bordered by the constellations of Vulpecula, Sagitta, Aquila, Aquarius, Equuleus and Pegasus. It is visible to all viewers at latitudes between +90° and -70° and is best seen at culmination during the month of September. Are you ready to start exploring Delphinus with binoculars? Then we’ll star with Alpha Delphini, whose name is Sualocin.

The small planetary nebula of NGC 6891. Credit: Judy Schmidt

Sualocin has seven components: A and G, a physical binary, and B, C, D, E, and F, which are optical and have no physical association with A and G. The primary is another rapid rotator star, whipping around at about 160 kilometers per second at its equator – or about 70 times faster than our Sun.

What it’s classification is, is confusing as well. It might a hydrogen-fusing main sequence star, and it subgiant that might just be starting to evolve. Wherever Suolocin lay in the scheme of things, there’s no use trying to resolve out the companion star, because it’s only a fraction of a second of arc away. However, Alpha’s nearby star, still makes for an interesting binocular view!

Now let’s look at Beta Delphini. Are you still ready for a smile? Good old Cacciatore wasn’t done yet. Beta’s name is Rotanev, which is a reversal of his Latinized family name, Venator. Here again we have a multiple star system. Rotanev has five components. Stars A and B are are a true physical binary star, while the others are simply optical companions. This time it’s cool to get out the telescope and split them!

Beta Delphini is a fine target for testing quality optics. At 97 light years from Earth, Rotanev’s components are only separated by about one stellar magnitude and 0.65 seconds of arc. By the way, in case you were wondering…. Nicolaus Venator was the assistant of the one and only Giuseppe Piazzi!

Are you ready for a look at Gamma Delphini? It’s the Y shape on the map. Here we have a binary star very worthy of even a small telescope. Located about a 101 light-years away from Earth, Gamma is one of the best known double stars in the night sky. The primary is a yellow-white dwarf star, a the secondary is an orange subgiant star. Both are separated by about one stellar magnitude and a very comfortable 9.2 seconds of arc apart.

The globular cluster NGC 7006. Credit: NASA

Regardless of their spectral class, take a look at how differently their colors appear in the telescope. While Gamma 1 (to the west) should by all rights be white, it often appears pale yellow orange, while Gamma 2 can appear yellow, green, or blue.

Before we put our binoculars away, let’s have a look at Delta Delphini – the figure “8” on our chart. Delta has no given name, but it has a partner. That’s right, it’s also a binary star. Its identical members are too close together to see separately and only by studying them spectroscopically were astronomers able to detect their 40.58 day orbital period.

Although Delta is officially classed as a type A (A7) giant star, it has a very strange low stellar temperature and an even stranger metal abundance. So what’s going on here? Chances are the Delta pair are really class F subgiants that have just ended core hydrogen fusion and both slightly variable. Do they orbit close to one another? You bet. So close, in fact, there orbit is only about the same distance as Mercury is from our Sun!

Now let’s take out the telescopes and have a look at NGC 7006 (RA 21h 1m 29.4 Dec +16 11′ 14.4) just a few arc minutes due east of Gamma. At magnitude 10, this small and powerful globular cluster might be mistaken for a stellar point in small telescopes at low power, for a very good reason… it’s very, very far away.

It is thought to be about 125 thousand light years from the galaxy’s core and over 135 thousand light years from us – far, far beyond the galaxy’s halo where it belongs. Even though it is a Class 1 globular, the most star dense in the Shapely?Sawyer classification system, and many observers comment that it looks more planetary nebula than it does a globular cluster!

Delphinus Constellation Map. Credit: IAU and Sky&Telescope magazine

Try NGC 6934 instead (RA 20 : 34.2 Dec +07 : 24) . This 50,000 light year distant globular cluster is much brighter and larger, though at Class VIII it doesn’t even come close to having as much stellar concentration. Discovered by Sir William Herschel on September 24, 1785, you’ll enjoy this one just for the rich star field that accompanies it. For larger telescope, you’ll enjoy the resolution and the study in contrasts between these two pairs.

Now let’s take a look at 12th magnitude planetary nebula, NGC 6891 (RA 20 : 15.2 Dec +12 : 42). Here we have an almost stellar appearance, but get tight on that focus and up the magnification to reveal its nature. This is anything but a star. As Martin A. Guerrero (et al) indicated in a 1999 study:

“Narrow-band and echelle spectroscopy observations show a great wealth of structures. The bright central nebula is surrounded by an attached shell and a detached outer halo. Both the inner and intermediate shells can be described as ellipsoids with similar major to minor axial ratios, but different spatial orientations. The kinematical ages of the intermediate shell and halo are 4800 and 28000 years, respectively. The inter-shell time lapse is in good agreement with the evolutionary inter-pulse time lapse. A highly collimated outflow is observed to protrude from the tips of the major axis of the inner nebula and impact on the outer edge of the intermediate shell. Kinematics and excitation of this outflow provide conclusive evidence that it is deflected during the interaction with the outer edge of the intermediate shell.”

If you’d like a real, big, telescope galaxy challenge, try galaxy group NGC 6927, NGC 6928 and NGC 6930. The brightest is NGC 6928 at magnitude 13.5, (RA 20h 32m 51.0s Dec: +09°55’49”). None of them will be easy… But what challenge is?

We have written many interesting articles about the constellation here at Universe Today. Here is What Are The Constellations?, What Is The Zodiac?, and Zodiac Signs And Their Dates.

Be sure to check out The Messier Catalog while you’re at it!

For more information, check out the IAUs list of Constellations, and the Students for the Exploration and Development of Space page on Canes Venatici and Constellation Families.

Sources:

Posted on by Tammy Plotner

The Corona Borealis Constellation

Alphecca is the brightest star in a C-shaped pattern of stars: the constellation Corona Borealis. It’s near the bright star Arcturus on the sky’s dome. Credit: EarthSky

Welcome to another edition of Constellation Friday! Today, in honor of the late and great Tammy Plotner, we take a look at the “Northern Crown” – the Corona Borealis constellation. Enjoy!

In the 2nd century CE, Greek-Egyptian astronomer Claudius Ptolemaeus (aka. Ptolemy) compiled a list of all the then-known 48 constellations. This treatise, known as the Almagest, would be used by medieval European and Islamic scholars for over a thousand years to come, effectively becoming astrological and astronomical canon until the early Modern Age.

One of these constellations was Corona Borealis, otherwise known as the “Northern Crown”. This small, faint constellation is the counterpart to Corona Australis – aka. the “Southern Crown”. It is bordered by the constellations of Hercules, Boötes and Serpens Caput, and has gone on to become one of the 88 modern constellations recognized by the International Astronomical Union.

Name and Meaning:

In mythology, Corona Borealis was supposed to represent the crown worn by Ariadne – a present from Dionysus. In Celtic lore, it was known as Caer Arianrhod, or the “Castle of the Silver Circle”, home to the Lady Arianrhod. Oddly enough, it was also known to the Native Americans as well, who referred to it as the “Camp Circle” – a heavenly rendition of their celestial ancestors.

Hercules and Corona Borealis, as depicted in Urania’s Mirror (c.?1825). Credit: Library of Congress

History of Observation:

Corona Borealis was one of the original 48 constellations mentioned in the Almagest by Ptolemy. To the medieval Arab astronomers, the constellation was known as al-Fakkah,  which means “separated” or “broken up”– a reference to the resemblance of the constellation’s stars to a loose string of jewels (sometimes portrayed as a broken dish). The name was later Latinized as Alphecca, which was later given to Alpha Coronae Borealis. In 1920, it was adopted by the International Astronomical Union (IAU) as one of the 88 modern constellations.

Notable Objects:

Corona Borealis has no bright stars, 6 main stars and 24 stellar members with Bayer/Flamsteed designations. It’s brightest star – Alpha Coronae Borealis (Alphecca) – is an eclipsing binary located about 75 light years away. The primary components is a white main sequence star that is believed to have a large disc around it (as evidenced by the amount of infrared radiation it emits), and may even have a planetary or proto-planetary system.

The second brightest star, Beta Coronae Borealis (Nusakan), is a spectroscopic binary that is located 114 light years away. It is an Alpha-2 Canum Venaticorum (ACV) type star, a class of variable (named after a star in the constellation Canes Venatici) that are main sequence stars that are chemically peculiar and have strong magnetic fields. Its traditional name, Nusakan, comes from the Arabic an-nasaqan which means “the (two) series.”

Corona Borealis Galaxy Cluster – Abell 2065. Credit: NASA (Wikisky)

Corona Borealis contains few Deep Sky Objects that would be visible to amateur astronomers. The most notable is the Corona Borealis Galaxy Cluster (aka. Abell 2065), a densely-populated cluster located between 1 and 1.5 billion years from Earth. It lies about one degree southwest of Beta Coronae Borealis, in the southwest corner of the constellation. The cluster contains more than 400 galaxies in an area spanning about one degree in the sky.

Corona Borealis also has five stars that have confirmed exoplanets orbiting them, most of which were detected using the radial velocity method. These include the the orange giant Epsilon Coronae Borealis, which has a Super-Jupiter (6.7 Jupiter masses) that orbits it at a distance of 1.3 AU and with a period of 418 days.

There’s also Kappa Coronae Borealis, an orange subgiant that is orbited by both a debris disk and a gas giant. This planet is 2.5 times as massive as Jupiter and orbits the star with a period of 3.4 years. Omicron Coronae Borealis is a clump giant (a type of red giant) with one confirmed exoplanet – a gas giant with 0.83 Jupiter masses that orbits its star every 187 days.

HD 145457 is an orange giant that has one confirmed planet of 2.9 Jupiter masses that takes 176 days to complete an orbit. XO-1 is a yellow main-sequence star located approximately 560 light-years away with a hot Jupiter (roughly the same size as Jupiter) exoplanet. This planet was discovered using the transit method and completes an orbit around its star every three days.

Artist’s concept of “hot Jupiter” orbiting a distant star. Credit: NASA/JPL-Caltech

Finding Corona Borealis:

Corona Borealis is visible at latitudes between +90° and -50° and is best seen at culmination during the month of July. Using binoculars, let’s start with Alpha Coronae Borealis. It’s name is Gemma, or on some star charts – Alphecca. At 75 light years away, we have a nice binary star system whose companion star produces a very faint eclipse every 17.3599 days. Even though Gemma is quite some distance in relative sky terms from Ursa Major, you might be surprised to know that it’s actually part of the Ursa Major moving star group!

Shift your attention to Beta Coronae Borealis. It’s traditional name Nusakan. Again, it looks like one star, but it’s actually two. Nusakan is a double star that’s about 114 light-years and the primary is a variable star that changes every so slightly about every 41 days. The two components are separated by about 0.25 arc seconds – way too close for amateur telescopes – but that’s not all. In 1944 F.J. Neubauer found a small variation in the radial velocity of Nusakan which may lead to a third orbiting body about 10 times the size of Jupiter.

Now have a look at Gamma. Again, we have a binary star that’s just too darn close to split with anything but a large telescope. Struve 1967 is a close binary with an orbit of 91 years. The position angle is 265º and separation about 0.2″. Instead, try focusing your attention on Zeta 1 and Zeta 2. Known as Struve 1965, this pair is a pretty blue white and they are well spaced at 7.03″ and about one stellar magnitude in difference. Nu1 and Nu2 are also very pretty in binoculars. Here we have an optic double star. Although they aren’t physically related, this widely seperated pair of orange giant stars is a pleasing sight in binoculars!

The location of the Corona Borealis Constellation. Credit: IAU/Sky&Telescope magazine

Out of all the singular stars here, you definitely have to take a look at R Coronae Borelis – known as R Cor Bor. Discovered nearly 200 years ago by English amateur, Edward Pigot, R Coronae Borealis is the prototype star of the R Coronae Borealis (RCB) type variables. They are very unusual type of variable star – one where the variability is caused by the formation of a cloud of carbon dust in the line of sight. Near the stellar photosphere, a cloud is formed – dimming the star’s visual brightness by several magnitudes.

Then the cloud dissipates as it moves away from the star. All RCB types are hydrogen-poor, carbon- and helium-rich, and high-luminosity. They are simultaneously eruptive and pulsating. They could fade anywhere from 1 to 9 magnitudes in a month… Or in a hundred days. It’s normally magnitude 6… But it could be magnitude 14. No wonder it has the nickname “Fade-Out star,” or “Reverse Nova”!

Unfortunately, Corona Borealis contains no bright deep sky objects, but it does have one claim to fame – the highly concentrated galaxy cluster, Abell 2065. For observers with larger telescope, many members of this fascinating 1-1.5 billion light years distant group are visible. This rich cluster of galaxies is located slightly more than a degree southwest of Beta Cor Bor and covers about a full degree of sky! Not for the faint of heart… Some of these galaxies list at magnitude 18….

We have written many interesting articles about the constellation here at Universe Today. Here is What Are The Constellations?, What Is The Zodiac?, and Zodiac Signs And Their Dates.

Be sure to check out The Messier Catalog while you’re at it!

For more information, check out the IAUs list of Constellations, and the Students for the Exploration and Development of Space page on Canes Venatici and Constellation Families.

Sources:

Posted on by Fraser Cain

Do Stars Move? Tracking Their Movements Across the Sky

How Fast Are Stars Moving?
How Fast Are Stars Moving?

The night sky, is the night sky, is the night sky. The constellations you learned as a child are the same constellations that you see today. Ancient people recognized these same constellations. Oh sure, they might not have had the same name for it, but essentially, we see what they saw.

But when you see animations of galaxies, especially as they come together and collide, you see the stars buzzing around like angry bees. We know that the stars can have motions, and yet, we don’t see them moving?

How fast are they moving, and will we ever be able to tell?

Stars, of course, do move. It’s just that the distances are so great that it’s very difficult to tell. But astronomers have been studying their position for thousands of years. Tracking the position and movements of the stars is known as astrometry.

We trace the history of astrometry back to 190 BC, when the ancient Greek astronomer Hipparchus first created a catalog of the 850 brightest stars in the sky and their position. His student Ptolemy followed up with his own observations of the night sky, creating his important document: the Almagest.

Printed rendition of a geocentric cosmological model from Cosmographia, Antwerp, 1539. Credit: Wikipedia Commons/Fastfission

In the Almagest, Ptolemy laid out his theory for an Earth-centric Universe, with the Moon, Sun, planets and stars in concentric crystal spheres that rotated around the planet. He was wrong about the Universe, of course, but his charts and tables were incredibly accurate, measuring the brightness and location of more than 1,000 stars.

A thousand years later, the Arabic astronomer Abd al-Rahman al-Sufi completed an even more detailed measurement of the sky using an astrolabe.

One of the most famous astronomers in history was the Danish Tycho Brahe. He was renowned for his ability to measure the position of stars, and built incredibly precise instruments for the time to do the job. He measured the positions of stars to within 15 to 35 arcseconds of accuracy. Just for comparison, a human hair, held 10 meters away is an arcsecond wide.

Also, I’m required to inform you that Brahe had a fake nose. He lost his in a duel, but had a brass replacement made.

In 1807, Friedrich Bessel was the first astronomer to measure the distance to a nearby star 61 Cygni. He used the technique of parallax, by measuring the angle to the star when the Earth was on one side of the Sun, and then measuring it again 6 months later when the Earth was on the other side.

With parallax technique, astronomers observe object at opposite ends of Earth’s orbit around the Sun to precisely measure its distance. Credit: Alexandra Angelich, NRAO/AUI/NSF.

Over the course of this period, this relatively closer star moves slightly back and forth against the more distant background of the galaxy.

And over the next two centuries, other astronomers further refined this technique, getting better and better at figuring out the distance and motions of stars.

But to really track the positions and motions of stars, we needed to go to space. In 1989, the European Space Agency launched their Hipparcos mission, named after the Greek astronomer we talked about earlier. Its job was to measure the position and motion of the nearby stars in the Milky Way. Over the course of its mission, Hipparcos accurately measured 118,000 stars, and provided rough calculations for another 2 million stars.

That was useful, and astronomers have relied on it ever since, but something better has arrived, and its name is Gaia.

Credit: ESA/ATG medialab; Background Credit: ESO/S. Brunier

Launched in December 2013, the European Space Agency’s Gaia in is in the process of mapping out a billion stars in the Milky Way. That’s billion, with a B, and accounts for about 1% of the stars in the galaxy. The spacecraft will track the motion of 150 million stars, telling us where everything is going over time. It will be a mind bending accomplishment. Hipparchus would be proud.

With the most precise measurements, taken year after year, the motions of the stars can indeed be calculated. Although they’re not enough to see with the unaided eye, over thousands and tens of thousands of years, the positions of the stars change dramatically in the sky.

The familiar stars in the Big Dipper, for example, look how they do today. But if you go forward or backward in time, the positions of the stars look very different, and eventually completely unrecognizable.

When a star is moving sideways across the sky, astronomers call this “proper motion”. The speed a star moves is typically about 0.1 arc second per year. This is almost imperceptible, but over the course of 2000 years, for example, a typical star would have moved across the sky by about half a degree, or the width of the Moon in the sky.

A 20 year animation showing the proper motion of Barnard’s Star. Credit: Steve Quirk, images in the Public Domain.

The star with the fastest proper motion that we know of is Barnard’s star, zipping through the sky at 10.25 arcseconds a year. In that same 2000 year period, it would have moved 5.5 degrees, or about 11 times the width of your hand. Very fast.

When a star is moving toward or away from us, astronomers call that radial velocity. They measure this by calculating the doppler shift. The light from stars moving towards us is shifted towards the blue side of the spectrum, while stars moving away from us are red-shifted.

Between the proper motion and redshift, you can get a precise calculation for the exact path a star is moving in the sky.

Credit: ESA/ATG medialab

We know, for example, that the dwarf star Hipparcos 85605 is moving rapidly towards us. It’s 16 light-years away right now, but in the next few hundred thousand years, it’s going to get as close as .13 light-years away, or about 8,200 times the distance from the Earth to the Sun. This won’t cause us any direct effect, but the gravitational interaction from the star could kick a bunch of comets out of the Oort cloud and send them down towards the inner Solar System.

The motions of the stars is fairly gentle, jostling through gravitational interactions as they orbit around the center of the Milky Way. But there are other, more catastrophic events that can make stars move much more quickly through space.

When a binary pair of stars gets too close to the supermassive black hole at the center of the Milky Way, one can be consumed by the black hole. The other now has the velocity, without the added mass of its companion. This gives it a high-velocity kick. About once every 100,000 years, a star is kicked right out of the Milky Way from the galactic center.

A rogue star being kicked out of a galaxy. Credit: NASA, ESA, and G. Bacon (STScI)

Another situation can happen where a smaller star is orbiting around a supermassive companion. Over time, the massive star bloats up as supergiant and then detonates as a supernova. Like a stone released from a sling, the smaller star is no longer held in place by gravity, and it hurtles out into space at incredible speeds.

Astronomers have detected these hypervelocity stars moving at 1.1 million kilometers per hour relative to the center of the Milky Way.

All of the methods of stellar motion that I talked about so far are natural. But can you imagine a future civilization that becomes so powerful it could move the stars themselves?

In 1987, the Russian astrophysicist Leonid Shkadov presented a technique that could move a star over vast lengths of time. By building a huge mirror and positioning it on one side of a star, the star itself could act like a thruster.

An example of a stellar engine using a mirror and a Dyson Swarm. Credit: Vedexent at English Wikipedia (CC BY-SA 3.0)

Photons from the star would reflect off the mirror, imparting momentum like a solar sail. The mirror itself would be massive enough that its gravity would attract the star, but the light pressure from the star would keep it from falling in. This would create a slow but steady pressure on the other side of the star, accelerating it in whatever direction the civilization wanted.

Over the course of a few billion years, a star could be relocated pretty much anywhere a civilization wanted within its host galaxy.

This would be a true Type III Civilization. A vast empire with such power and capability that they can rearrange the stars in their entire galaxy into a configuration that they find more useful. Maybe they arrange all the stars into a vast sphere, or some kind of geometric object, to minimize transit and communication times. Or maybe it makes more sense to push them all into a clean flat disk.

Amazingly, astronomers have actually gone looking for galaxies like this. In theory, a galaxy under control by a Type III Civilization should be obvious by the wavelength of light they give off. But so far, none have turned up. It’s all normal, natural galaxies as far as we can see in all directions.

For our short lifetimes, it appears as if the sky is frozen. The stars remain in their exact positions forever, but if you could speed up time, you’d see that everything is in motion, all the time, with stars moving back and forth, like airplanes across the sky. You just need to be patient to see it.

Posted on by Tammy Plotner

The Cetus Constellation

The Cetus Constellation. Credit and Copyright ©: Torsten Bronger/Wikipedia Commons

Welcome back to Constellation Friday! Today, in honor of the late and great Tammy Plotner, we will be dealing with the sea monster – the Cetus constellation!

In the 2nd century CE, Greek-Egyptian astronomer Claudius Ptolemaeus (aka. Ptolemy) compiled a list of all the then-known 48 constellations. This treatise, known as the Almagest, would be used by medieval European and Islamic scholars for over a thousand years to come, effectively becoming astrological and astronomical canon until the early Modern Age.

One of these constellations is Cetus, which was named in honor of the sea monster from Greek mythology.  Cetus is the fourth largest constellation in the sky, the majority of which resides just below the ecliptic plane. Here, it is bordered by many “watery” constellations – including Aquarius, Pices, Eridanus, Piscis Austrinus, Capricornus – as well as Aries, Sculptor, Fornax and Taurus. Today, it is one of the 88 modern constellations recognized by the IAU.

Name and Meaning:

In mythology, Cetus ties in with the legendary Cepheus,Cassiopeia, Andromeda, Perseus tale – for Cetus is the monster to which poor Andromeda was to be sacrificed. (This whole tale is quite wonderful when studied, for we can also tie in Pegasus as Perseus’ horse, Algol and the whom he slew to get to Andromeda and much, much more!)

Cetus, as represented by Sidney Hall in this card from Urania’s Mirror (1825). Credit: Library of Congress/Sidney Hall

As for poor, ugly Cetus. He also represents the gates to the underworld thanks to his position just under the ecliptic plane. Arab legend has it that Cetus carries two pearl necklaces – one broken and the other intact – which oddly enough, you can see among its faint stars in the circular patterns when nights are dark. No matter what the legends are, Cetus is an rather dim, but interesting constellation!

History of Observation:

Cetus was one of many Mesopotamian constellations that passed down to the Greeks. Originally, Cetus may have been associated with a whale, and is often referred to as the Whale. However, its most common representation is that of the sea monster that was slain by Perseus.

In the 17th century, Cetus was depicted variously as a “dragon fish” (by Johann Bayer), and as a whale-like creature by famed 17th-century cartographers Willem Blaeu and Andreas Cellarius. However, Cetus has also been variously depicted with animal heads attached to an aquatic animal body.

The constellation is also represented in many non-Western astrological systems.In Chinese astronomy, the stars of Cetus are found among the Black Tortoise of the North (B?i F?ng Xuán W?) and the White Tiger of the West (X? F?ng Bái H?).

Cetus, as depicted by famed 17th century cartographer Willem Blaeu, 1602. Credit: WIkipedia Commons/Erik Lernestål

Notable Features:

Cetus sprawls across 1231 square degrees of sky and contains 15 main stars, highlighted by 3 bright stars and 88 Bayer/Flamsteed designations. It’s brightest star is Beta Ceti, otherwise known as Deneb Kaitos (Diphda), a type K0III orange giant which is located approximately 96.3 light years away. This star has left its main sequence and is on its way to becoming a red giant.

The name Deneb Kaitos is derived from the Arabic “Al Dhanab al Kaitos al Janubiyy”, which translates as “the southern tail of Cetus”. The name Diphda comes “ad-dafda at-tani“, which is Arabic for “the second frog” – the star Fomalhaut in neighboring Piscis Austrinus is usually referred to as the first frog.)

Then there’s Alpha Ceti, a very old red giant star located approximately 249 light years from Earth. It’s traditional name (Menkar), is derived from the Arabic word for “nostril”. Then comes Omicron Ceti, also known as Mira, binary star consisting located approximately 420 light years away. This binary system consists of an oscillating variable red giant (Mira A).

After being recorded for the first time by David Fabricius (on August 3, 1596), Mira has since gone on to become the prototype for the Mira class of variables (of which there are six or seven thousand known examples). These stars are red giants whose surfaces oscillate in such a way as to cause variations in brightness over periods ranging from 80 to more than 1,000 days.

Composite image of Messier 77 (NGC 1068), showing it in the visible, X-ray, and radio spectrums. Credit: NASA/CXC/MIT/C.Canizares/D.Evans et al/STScI/NSF/NRAO/VLA

Cetus is also home to many Deep Sky Objects. A notable examples is the barred spiral galaxy known as Messier 77, which is located approximately 47 million light years away and is 170,000 light years in diameter, making it one of the largest galaxies listed in Messier’s catalogue. It has an Active Galactic Nucleus (AGN) which is obscured from view by intergalactic dust, but remains an active radio source.

Then there’s NGC 1055, a spiral galaxy that lies just 0.5 north by northeast of Messier 77. It is located approximately 52 million light years away and is seen edge-on from Earth. Next to Messier 77, NGC 1055 is a largest member of a galaxy group – measuring 115,800 light years in diameter – that also includes NGC 1073 and several smaller irregular galaxies. It has a diameter of about 115,800 light years. The galaxy is a known radio source.

Finding Cetus:

Cetus is the fourth largest constellation in the sky, is visible at latitudes between +70° and -90° and is best seen at culmination during the month of November. Of all the stars in Cetus, the very first you must look for in binoculars is Mira. Omicron Ceti was the very first variable star discovered and was perhaps known as far back as ancient China, Babylon or Greece. The variability was first recorded by the astronomer David Fabricius while observing Mercury.

Now aim your binoculars at Alpha Ceti. It’s name is Menkar and we do know something about it. Menkar is an old and dying star, long past the hydrogen and perhaps even past the helium stage of its stellar evolution. Right now it’s a red giant star but as it begins to burn its carbon core it will likely become highly unstable before finally shedding its outer layers and forming a planetary nebula, leaving a relatively large white dwarf remnant.

Location of Mira and Tau Ceti. Credit: Constellation Guide/Torsten Bronger

Hop down to Beta Ceti – Diphda. Oddly enough, Diphda is actually the brightest star in Cetus, despite its beta designation. It is a giant star with a stellar corona that’s brightening with age – exerting about 2000 times more x-ray power than our Sun! For some reason, it has gone into an advanced stage if stellar evolution called core helium burning – where it is converting helium directly to carbon.

Are you ready to get out your telescope now? Then aim at Diphda and drop south a couple of degrees for NGC 247. This is a very definite spiral galaxy with an intense “stellar” nucleus! Sitting right up in the eyepiece as a delightful oval, the NGC 247 is has a very proper galaxy structure with a defined core area and a concentration that slowly disperses toward its boundaries with one well-defined dark dust lane helping to enhance a spiral arm. Most entertaining! Continuing “down” we move on to the NGC 253. Talk about bright!

Very few galactic studies come in this magnitude (small telescopes will pick it up very well, but it requires large aperture to study structure.) Very elongated and hazy, it reminds me sharply of the “Andromeda Galaxy”. The center is very concentrated and the spiral arms wrap their way around it beautifully! Dust lanes and bright hints of concentration are most evident. and its most endearing feature is that it seems to be set within a mini “Trapezium” of stars. A very worthy study…

Now, let’s hop off to Delta Ceti, shall we? I want to rock your world – because spiral galaxy M77 rocked mine! Once again, easily achieved in the small telescope, Messier 77 comes “alive” with aperture. This one has an incredible nucleus and very pronounced spiral arms – three big, fat ones! Underscored by dark dust lanes, the arms swirl away from the center in a galactic display that takes your breath away!

The location of the Cetus Constellation. Credit: IAU/Sky&Telescope magazine

The “mottling” inside the structure is not just a hint in this ovalish galaxy. I guarantee you won’t find this one “ho hum”… how could you when you know you’re looking at something that’s 47.0 million light-years away! Messier 77 is an active galaxy with an Active Galactic Nucleus (AGN) and one of the brightest Seyfert galaxies known.

Now, return to Delta and the “fall line” runs west to east on the north side. First up is galaxy NGC 1073, a very pretty little spiral galaxy with a very “stretched” appearing nucleus that seems to be “ringed” by its arms! Continuing along the same trajectory, we find the NGC 1055. Oh, yes… Edge-on, lenticular galaxy! This soft streak of light is accompanied by a trio of stars. The galaxy itself is cut through by a dark dust lane, but what appears so unusual is the core is to one side!

Now we’ve made it to back to the incredible M77, but let’s keep on the path and pick up the NGC 1087 – a nice, even-looking spiral galaxy with a bright nucleus and one curved arm. Ready to head for the beautiful variable Mira again? Then let her be the guide star, because halfway between there and Delta is the NGC 936 – a soft spiral galaxy with a “saturn” shaped nucleus. Nice starhoppin’!

We have written many interesting articles about the constellation here at Universe Today. Here is What Are The Constellations?, What Is The Zodiac?, and Zodiac Signs And Their Dates.

Be sure to check out The Messier Catalog while you’re at it!

For more information, check out the IAUs list of Constellations, and the Students for the Exploration and Development of Space page on Canes Venatici and Constellation Families.

Sources:

Posted on by Tammy Plotner

The Canis Minor Constellation

View of the night sky in North Carolina, showing the constellations of Orion, Hyades, Canis Major and Canis Minor. Credit: NASA

Welcome back to Constellation Friday! Today, in honor of the late and great Tammy Plotner, we will be dealing with the “little dog” – the Canis Minor constellation!

In the 2nd century CE, Greek-Egyptian astronomer Claudius Ptolemaeus (aka. Ptolemy) compiled a list of all the then-known 48 constellations. This treatise, known as the Almagest, would be used by medieval European and Islamic scholars for over a thousand years to come, effectively becoming astrological and astronomical canon until the early Modern Age.

One of these constellations was Canis Minor, a small constellation in the northern hemisphere. As a relatively dim collection of stars, it contains only two particularly bright stars and only faint Deep Sky Objects. Today, it is one of the 88 constellations recognized by the International Astronomical Union, and is bordered by the Monoceros, Gemini, Cancer and Hydra constellation.

Name and Meaning:

Like most asterisms named by the Greeks and Romans, the first recorded mention of this constellation goes back to ancient Mesopotamia. Specifically, Canis Minor’s brightest stars – Procyon and Gomeisa – were mentioned in the Three Stars Each tablets (ca. 1100 BCE), where they were referred to as MASH.TAB.BA (or “twins”).

The Winter Hexagon, which contains parts of the Auriga, Canis Major, Canis Minor, Gemini, Monoceros, Orion, Taurus, Lepus and Eridanus constellations. Credit: constellation-guide.com
The Winter Hexagon, which contains parts of the Auriga, Canis Major, Canis Minor, Gemini, Monoceros, Orion, Taurus, Lepus and Eridanus constellations. Credit: constellation-guide.com

In the later texts that belong to the MUL.APIN, the constellation was given the name DAR.LUGAL (“the star which stands behind it”) and represented a rooster. According to ancient Greco-Roman mythology, Canis Minor represented the smaller of Orion’s two hunting dogs, though they did not recognize it as its own constellation.

In Greek mythology, Canis Minor is also connected with the Teumessian Fox, a beast turned into stone with its hunter (Laelaps) by Zeus. He then placed them in heaven as Canis Major (Laelaps) and Canis Minor (Teumessian Fox). According to English astronomer and biographer of constellation history Ian Ridpath:

“Canis Minor is usually identified as one of the dogs of Orion. But in a famous legend from Attica (the area around Athens), recounted by the mythographer Hyginus, the constellation represents Maera, dog of Icarius, the man whom the god Dionysus first taught to make wine. When Icarius gave his wine to some shepherds for tasting, they rapidly became drunk. Suspecting that Icarius had poisoned them, they killed him. Maera the dog ran howling to Icarius’s daughter Erigone, caught hold of her dress with his teeth and led her to her father’s body. Both Erigone and the dog took their own lives where Icarius lay.

“Zeus placed their images among the stars as a reminder of the unfortunate affair. To atone for their tragic mistake, the people of Athens instituted a yearly celebration in honour of Icarius and Erigone. In this story, Icarius is identified with the constellation Boötes, Erigone is Virgo and Maera is Canis Minor.”

Canis Minor, as depicted by Johann Bode in his 1801 work Uranographia. Credit: Wikipedia Commons/Alessio Govi
Canis Minor, as depicted by Johann Bode in his 1801 work Uranographia. Credit: Wikipedia Commons/Alessio Govi

To the ancient Egyptians, this constellation represented Anubis, the jackal god. To the ancient Aztecs, the stars of Canis Minor were incorporated along with stars from Orion and Gemini into as asterism known as “Water”, which was associated with the day. Procyon was also significant in the cultural traditions of the Polynesians, the Maori people of New Zealand, and the Aborigines of Australia.

In Chinese astronomy, the stars corresponding to Canis Minor were part of the The Vermilion Bird of the South. Along with stars from Cancer and Gemini, they formed the asterisms known as the Northern and Southern River, as well as the asterism Shuiwei (“water level”), which represented an official who managed floodwaters or a marker of the water level.

History of Observation:

Canis Minor was one of the original 48 constellations included by Ptolemy in his the Almagest. Though not recognized as its own asterism by the Ancient Greeks, it was added by the Romans as the smaller of Orion’s hunting dogs. Thanks to Ptolemy’s inclusion of it in his 2nd century treatise, it would go on to become part of astrological and astronomical traditions for a thousand years to come.

For medieval Arabic astronomers, Canis Minor continued to be depicted as a dog, and was known as “al-Kalb al-Asghar“. It was included in the Book of Fixed Stars by Abd al-Rahman al-Sufi, who assigned a canine figure to his stellar diagram. Procyon and Gomeisa were also named for their proximity to Sirius; Procyon being named the “Syrian Sirius (“ash-Shi’ra ash-Shamiya“) and Gomeisa the “Sirius with bleary eyes” (“ash-Shira al-Ghamisa“).

Monoceros and the obsolete constellation Atelier Typographique. Credit: Library of Congress
The constellation Canis Minor, shown alongside Monoceros and the obsolete constellation Atelier Typographique. Credit: Library of Congress

The constellation was included in Syndey Hall’s Urania’s Mirror (1825) alongside Monoceros and the now obsolete constellation Atelier Typographique. Many alternate names were suggested between the 17th and 19th centuries in an attempt to simplify celestial charts. However, Canis Minor has endured; and in 1922, it became one the 88 modern constellations to be recognized by the IAU.

Notable Features:

Canis Minor contains two primary stars and 14 Bayer/Flamsteed designated stars. It’s brightest star, Procyon (Alpha Canis Minoris), is also the seventh brightest star in the sky. With an apparent visual magnitude of 0.34, Procyon is not extraordinarily bright in itself. But it’s proximity to the Sun – 11.41 light years from Earth – ensures that it appears bright in the night sky.

The star’s name is derived from the Greek word which means “before the dog”, a reference to the fact that it appears to rise before Sirius (the “Dog Star”) when observed from northern latitudes. Procyon is a binary star system, composed of a white main sequence star (Procyon A) and Procyon B, a DA-type faint white dwarf as the companion.

Procyon is part of the Winter Triangle asterism, along with Sirius in Canis Major and Betelgeuse in the constellation Orion. It is also part of the Winter Hexagon, along with the stars Capella in Auriga, Aldebaran in Taurus, Castor and Pollux in Gemini, Rigel in Orion and Sirius in Canis Major.

The stars of the Winter Triangle and the Winter Hexagon. Credit: constellation-guide.com
The stars of the Winter Triangle and the Winter Hexagon. Credit: constellation-guide.com

Next up is Gomeisa, the second brightest star in Canis Minor. This hot, B8-type main sequence star is classified as a Gamma Cassiopeiae variable, which means that it rotates rapidly and exhibits irregular variations in luminosity because of the outflow of matter. Gomeisa is approximately 170 light years from Earth and the name is derived from the Arabic “al-ghumaisa” (“the bleary-eyed woman”).

Canis Minor also has a number of Deep Sky Objects located within it, but all are very faint and difficult to observe. The brightest is the spiral galaxy NGC 2485 (apparent magnitude of 12.4), which is located 3.5 degrees northeast of Procyon. There is one meteor shower associated with this constellation, which are the Canis-Minorids.

Finding Canis Minor:

Though it is relatively faint, Canis Minor and its stars can be viewed using binoculars. Start with the brightest, Procyon – aka. Alpha Canis Minoris (Alpha CMi). If you’re unsure of which bright star is, you’ll find it in the center of the diamond shape grouping in the southwest area. Known to the ancients as Procyon – “The Little Dog Star” – it’s the seventh brightest star in the night sky and the 13th nearest to our solar system.

For over 100 years, astronomers have known this brilliant star had a companion. Being 15,000 times fainter than the parent star, Procyon B is an example of a white dwarf whose diameter is only about twice that of Earth. But its density exceeds two tons per cubic inch! (Or, a third of a metric ton per cubic centimeter). While only very large telescopes can resolve this second closest of the white dwarf stars, even the moonlight can’t dim its beauty.

The Winter Triangle. Credit: constellation-guide.com/Stellarium software
The Winter Triangle. Credit: constellation-guide.com/Stellarium software

Now hop over to Beta CMi. Known by the very strange name of Gomeisa (“bleary-eyed woman”), it refers to the weeping sister left behind when Sirius and Canopus ran to the south to save their lives. Located about 170 light years away from our Solar System, Beta is a blue-white class B main sequence dwarf star with around 3 times the mass of our Sun and a stellar luminosity over 250 times that of Sol.

Gomeisa is a fast rotator, spinning at its equator with a speed of at least 250 kilometers per second (125 times our  Sun’s rotation speed) giving the star a rotation period of about a day. Sunspots would appear to move very quickly there! According to Jim Kaler, Professor Emeritus of Astronomy at the University of Illinois:

“Since we may be looking more at the star’s pole than at its equator, it may be spinning much faster, and indeed is rotating so quickly that it is surrounded by a disk of matter that emits radiation, rendering Gomeisa a “B-emission” star rather like Gamma Cassiopeiae and Alcyone. Like these two, Gomeisa is distinguished by having the size of its disk directly measured, the disk’s diameter almost four times larger than the star. Like quite a number of hot stars (including Adhara, Nunki, and many others), Gomeisa is also surrounded by a thin cloud of dusty interstellar gas that it helps to heat.”

Now hop over to Gamma Canis Minoris, an orange K-type giant with an apparent magnitude of +4.33. It is a spectroscopic binary, has an unresolved companion which has an orbital period of 389 days, and is approximately 398 light years from Earth. And next is Epsilon Canis Minoris, a yellow G-type bright giant (apparent magnitude of +4.99) which is approximately 990 light years from Earth.

The location of Canis Minor in the northern hemisphere. Credit: IAU/Sky&Telescope magazine
The location of Canis Minor in the northern hemisphere. Credit: IAU/Sky&Telescope magazine

For smaller telescopes, the double star Struve 1149 is a lovely sight, consisting of a yellow primary star and a faintly blue companion. For larger telescopes and GoTo telescopes, try NGC 2485 (RA 07 56.7 Dec +07 29), a magnitude 13 spiral galaxy that has a small, round glow, sharp edges and a very bright, stellar nucleus. If you want one that’s even more challenging, try NGC 2508 (RA 08 02 0 Dec +08 34).

Canis Minor lies in the second quadrant of the northern hemisphere (NQ2) and can be seen at latitudes between +90° and -75°. The neighboring constellations are Cancer, Gemini, Hydra, and Monoceros, and it is best visible during the month of March.

We have written many interesting articles about the constellation here at Universe Today. Here is What Are The Constellations?, What Is The Zodiac?, and Zodiac Signs And Their Dates.

Be sure to check out The Messier Catalog while you’re at it!

For more information, check out the IAUs list of Constellations, and the Students for the Exploration and Development of Space page on Canes Venatici and Constellation Families.

Sources:

Posted on by Tammy Plotner

The Andromeda Constellation

A photo of the constellation Andromeda with all Bayer-designated stars marked and the IAU figure drawn in. Credit: Roberto Mura/Wikipedia Commons

In the 2nd century CE, Greek-Egyptian astronomer Claudius Ptolemaeus (aka. Ptolemy) compiled a list of the then-known 48 constellations. His treatise, known as the Almagest, would be used by medieval European and Islamic scholars for over a thousand years to come. Thanks to the development of modern telescopes and astronomy, this list was amended by the early 20th century to include the 88 constellation that are recognized by the International Astronomical Union (IAU) today.

Of these, Andromeda is one of the oldest and most widely recognized. Located north of the celestial equator, this constellation is part of the family of Perseus, Cassiopeia, and Cepheus. Like many constellation that have come down to us from classical antiquity, the Andromeda constellation has deep roots, which may go all the way back to ancient Babylonian astronomy.

Continue reading “The Andromeda Constellation”

Posted on by Ken Kremer

Mobile Launcher Upgraded to Launch NASA’s Mammoth ‘Journey to Mars’ Rocket

Looking up from beneath the enlarged exhaust hole of the Mobile Launcher to the 380 foot-tall tower astronauts will ascend as their gateway for missions to the Moon, Asteroids and Mars. The ML will support NASA's Space Launch System (SLS) and Orion spacecraft during Exploration Mission-1 at NASA's Kennedy Space Center in Florida. Credit: Ken Kremer/kenkremer.com

Looking up from beneath the enlarged exhaust hole of the Mobile Launcher to the 380 foot-tall tower astronauts will ascend as their gateway for missions to the Moon, Asteroids and Mars. The ML will support NASA’s Space Launch System (SLS) and Orion spacecraft during Exploration Mission-1 at NASA’s Kennedy Space Center in Florida. Credit: Ken Kremer/kenkremer.com
Story/photos updated[/caption]

KENNEDY SPACE CENTER, FL – NASA’s Mobile Launcher (ML) is undergoing major upgrades and modifications at the Kennedy Space Center in Florida enabling the massive structure to launch the agency’s mammoth Space Launch System (SLS) rocket and Orion crew capsule on a grand ‘Journey to Mars.’

“We just finished up major structural steel modifications to the ML, including work to increase the size of the rocket exhaust hole,” Eric Ernst, NASA Mobile Launch project manager, told Universe Today during an exclusive interview and inspection tour up and down the Mobile Launcher.

Indeed the Mobile Launcher is the astronauts gateway to deep space expeditions and missions to Mars.

Construction workers are hard at work upgrading and transforming the 380-foot-tall, 10.5-million-pound steel structure into the launcher for SLS and Orion – currently slated for a maiden blastoff no later than November 2018 on Exploration Mission-1 (EM-1).

“And now we have just started the next big effort to get ready for SLS.”

SLS and Orion are NASA’s next generation human spaceflight vehicles currently under development and aimed at propelling astronauts to deep space destinations, including the Moon and an asteroid in the 2020s and eventually a ‘Journey to Mars’ in the 2030s.

Floor level view of the Mobile Launcher and enlarged exhaust hole with 380 foot-tall launch tower astronauts will ascend as their gateway for missions to the Moon, Asteroids and Mars. The ML will support NASA's Space Launch System (SLS) and Orion spacecraft for launches from Space Launch Complex 39B the Kennedy Space Center in Florida. Credit: Ken Kremer/kenkremer.com
Floor level view of the Mobile Launcher and enlarged exhaust hole with 380 foot-tall launch tower astronauts will ascend as their gateway for missions to the Moon, Asteroids and Mars. The ML will support NASA’s Space Launch System (SLS) and Orion spacecraft for launches from Space Launch Complex 39B at the Kennedy Space Center in Florida. Credit: Ken Kremer/kenkremer.com

The mobile launcher was originally built several years ago to accommodate NASA’s less powerful, lighter and now cancelled Ares-1 rocket. It therefore requires extensive alterations to accommodate the vastly more powerful and heavier SLS rocket.

“The ML was initially developed for Ares 1, a much smaller rocket,” Ernst explained to Universe Today.

“So the exhaust hole was much smaller.”

Whereas the Ares-1 first stage booster was based on using a single, more powerful version of the Space Shuttle Solid Rocket Boosters, the SLS first stage is gargantuan and will be the most powerful rocket the world has ever seen.

The SLS first stage comprises two shuttle derived solid rocket boosters and four RS-25 power plants recycled from their earlier life as space shuttle main engines (SSMEs). They generate a combined 8.4 million pounds of thrust – exceeding that of NASA’s Apollo Saturn V moon landing rocket.

Therefore the original ML exhaust hole had to be gutted and nearly tripled in width.

“The exhaust hole used to be about 22 x 22 feet,” Ernst stated.

“Since the exhaust hole was much smaller, we had to deconstruct part of the tower at the base, in place. The exhaust hole had to be made much bigger to accommodate the SLS.”

Construction crews extensively reworked the exhaust hole and made it far wider to accommodate SLS compared to the smaller one engineered and already built for the much narrower Ares-1, which was planned to generate some 3.6 million pounds of thrust.

“So we had to rip out a lot of steel,” Mike Canicatti, ML Construction Manager told Universe Today.

“For the exhaust hole [at the base of the tower], lots of pieces of [existing] steel were taken out and other new pieces were added, using entirely new steel.”

“The compartment for the exhaust hole used to be about 22 x 22 feet, now it’s about 34 x 64 feet.”

Looking down to the enlarged 64 foot wide exhaust hole from the top of NASA’s 380 foot-tall Mobile Launch tower. Astronauts will board the Orion capsule atop the Space Launch System (SLS) rocket for launches from Space Launch Complex 39B the Kennedy Space Center in Florida. Credit: Ken Kremer/kenkremer.com
Looking down to the enlarged 64 foot wide exhaust hole from the top of NASA’s 380 foot-tall Mobile Launch tower. Astronauts will board the Orion capsule atop the Space Launch System (SLS) rocket for launches from Space Launch Complex 39B the Kennedy Space Center in Florida. Credit: Ken Kremer/kenkremer.com

In fact this involved the demolition of over 750 tons of old steel following by fabrication and installation of more than 1,000 tons of new steel. It was also reinforced due to the much heavier weight of SLS.

“It was a huge effort and structural engineers did their job. The base was disassembled and reassembled in place” – to enlarge the exhaust hole.

“So basically we gutted major portions of the base out, put in new walls and big structural girders,” Ernst elaborated.

“And we just finished up that major structural steel modification on the exhaust hole.”

Top view across the massive 34 foot-wide, 64 foot-long exhaust hole excavated out of NASA’s Mobile Launcher that will support launches of the Space Launch System (SLS) rocket from Space Launch Complex 39B at the Kennedy Space Center in Florida. Credit: Ken Kremer/kenkremer.com
Top view across the massive 34 foot-wide, 64 foot-long exhaust hole excavated out of NASA’s Mobile Launcher that will support launches of the Space Launch System (SLS) rocket from Space Launch Complex 39B at the Kennedy Space Center in Florida. Credit: Ken Kremer/kenkremer.com

Meanwhile the 380 foot-tall tower that future Orion astronauts will ascend was left in place.

“The tower portion itself did not need to be disassembled.”

IMG_8393_1a_KSC ML_Ken Kremer

The Ares rockets originally belonged to NASA’s Constellation program, whose intended goal was returning American astronauts to the surface of the Moon by 2020.

Ares-1 was slated as the booster for the Orion crew capsule. However, President Obama cancelled Constellation and NASA’s Return to the Moon soon after entering office.

Since then the Obama Administration and Congress worked together in a bipartisan manner together to fashion a new space hardware architecture and granted approval for development of the SLS heavy lift rocket to replace the Ares-1 and heavy lift Ares-5.

Sending astronauts on a ‘Journey to Mars’ is now NASA’s agency wide and overarching goal for the next few decades of human spaceflight.

But before SLS can be transported to its launch pad at Kennedy’s Space Launch Complex 39-B for the EM-1 test flight the next big construction step has to begin.

“So now we have just started the next big effort to get ready for SLS.”

This involves installation of Ground Support Equipment (GSE) and a wide range of launch support services and systems to the ML.

“The next big effort is the GSE installation contract,” Ernst told me.

“We have about 40+ ground support and facility systems to be installed on the ML. There are about 800 items to be installed, including about 300,000-plus feet of cable and several miles of piping and tubing.”

“So that’s the next big effort to get ready for SLS. It’s about a 1.5 year contract and it was just awarded to J.P. Donovan Construction Inc. of Rockledge, Florida.”

“The work just started at the end of August.”

NASA currently plans to roll the ML into the Vehicle Assembly Building in early 2017 for stacking of SLS and Orion for the EM-1 test flight.

View of NASA’s future SLS/Orion launch pad at Space Launch Complex 39B from atop Mobile Launcher at the Kennedy Space Center in Florida. Former Space Shuttle launch pad 39B is now undergoing renovations and upgrades to prepare for SLS/Orion flights starting in 2018. Credit: Ken Kremer/kenkremer.com
View of NASA’s future SLS/Orion launch pad at Space Launch Complex 39B from atop Mobile Launcher at the Kennedy Space Center in Florida. Former Space Shuttle launch pad 39B is now undergoing renovations and upgrades to prepare for SLS/Orion flights starting in 2018. Credit: Ken Kremer/kenkremer.com

The SLS/Orion mounted stack atop the ML will then roll out to Space Launch Complex 39B for the 2018 launch from the Kennedy Space Center.

Pad 39B is also undergoing radical renovations and upgrades, transforming it from its use for NASA’s now retired Space Shuttle program into a modernized 21st century launch pad. Watch for my upcoming story.

Artist concept of the SLS Block 1 configuration. Credit: NASA
Artist concept of the SLS Block 1 configuration mounted on the Mobile Launcher. Credit: NASA

Stay tuned here for Ken’s continuing Earth and planetary science and human spaceflight news.

Ken Kremer

United Launch Alliance Atlas V rocket with MUOS-4 US Navy communications satellite poised at pad 41 at Cape Canaveral Air Force Station, FL, set for launch on Sept. 2, 2015. EDT. View from atop NASA’s SLS mobile launcher at the Kenned Space Center. Credit: Ken Kremer/kenkremer.com
View from atop NASA’s SLS mobile launcher at the Kennedy Space Center, looking out to United Launch Alliance Atlas V rocket with MUOS-4 US Navy communications satellite poised at pad 41 at Cape Canaveral Air Force Station, FL, ‘prior to launch on Sept. 2, 2015. EDT. Credit: Ken Kremer/kenkremer.com
Posted on by Mark Mortimer

Book Review: The Seventh Landing — Going Back to the Moon, This Time to Stay

The Seventh Landing by

Can you remember back to your first love? The one that left you in tears, wondering what ever caused such a disaster. Well, that feeling might come back to you if you read Michael Carroll’s “The Seventh Landing.” For you see, this book anticipates the imminent Constellation program of 2009 that was going to return the United States to the Moon and then on to Mars. We know what happened instead and we know a few tears must have been shed, perhaps even yours.

Yes, this book is all about the Constellation program and its Ares I and ARES V launch vehicles. But more than that, and what makes it still applicable today, is that the book really gets into a lunar landing program as the next step in humankind’s expansion off of Earth — and how it’s the logical precursor to the next step: a settlement on Mars.

This logical progression jumps right out via the table of contents. First there’s an excellent chapter that recovers what’s already transpired; the good and bad of both the Apollo program and the early Soviet space program. The writing style and copious quantities of vintage photographs bring a sense of immediacy and presence.

The second chapter takes you to the promised land. This land is full of large expendable launch vehicles; human rated and ready to transport material and supplies. Here’s where the value of this book continues on to today. That is, the book provides a systems analysis point of view on, for instance, why various engines would be better or how to use ping pong balls to design a lunar capsule. With this, the reader can start to get a grasp on the complexity of this undertaking. Interesting yes, but what about that purpose again? Oh yes, it was to put humans on the Moon. Well that’s the book’s next chapter.

Bring on the Shackleton crater, the nights of -233C and the dust. Lots and lots of dust. As it states, sure there may be some engineering challenges but hey, we’ve been to the Moon already and we’ve been continuing to research it nearly non-stop so we should certainly be able to go back there to live; even if it won’t be easy.

The remainder of the book is somewhat like a lover after their first kiss; all hopes and aspirations. The chapters progress on to the reasons for returning to the Moon or what to do once there. Then, of course, there’s that final question that remains and which the book outlines but doesn’t answer. That is, “Is the Moon really the next step for humanity or should we go Mars direct?” Well, since 2009, there’s been lots of discussion on this topic though as we’ve seen, there’s been very little substance. So in a sense, this book is still a wonderful jumping off point for someone who wants to understand where things lie with regard to the expansion of humans into space even if it won’t be via the launch vehicles of the Constellation program.

Yes, this book has lots of technical detail on elements needed for a Moon program. What also becomes apparent on reading the book is that the author is also an award winning artist of space themes. Thus, the reader receives a reward simply by viewing the book’s images. For instance, it’s got a wonderful image of Werner Von Braun’s plan of space “boats” winging down through the Martian atmosphere. Or, there’s a rendered image of an Altair lander doing a final approach to an established base on the rim of Shackleton. Many other renderings take the reader out from the germane and into a visual playground of possibilities. Certainly, if the Constellation program had been funded, then there’s a good chance that some of these images might be close to reality. But, we will just have to be content with the images for now.

Sometimes being content is the best we can do. For example, perhaps you`ve keep secreted away an old photograph of that first love. It’s so far away that no one will ever know but you. And maybe on a dark lonely night you pull out that photograph and imagine what might have been. Or maybe on that dark night you pull out a copy of Michael Carroll’s “The Seventh Landing” and dream about what might have been. And, of course, you will remember that tomorrow is a new day when anything might come true, even dreams.

Find out more about the book at Springer’s website, and learn more about the author, Michael Carroll, at his website.

Posted on by Elizabeth Howell

What Are the Stars in Orion’s Belt?

The constellation Orion. Credit: Matthew Spinelli NASA/APOD

Orion dominates the winter sky in the northern hemisphere. Its large size and  collection of bright stars — such as Betelgeuse at the shoulder, Rigel below the belt, and the three stars in the belt — make it easy to spot, even for beginning stargazers.

So how about those stars in the belt? They’re one of the most famous asterisms in Western culture, but beyond what we see with our eyes, what are their astronomical properties?

Introduction to Orion

First, a brief word about the constellation itself. In many mythologies, the shape is seen as a human figure — and in Greek mythology, it was named after a hunter, according to a web page from the Chandra X-Ray Observatory.

There are several “reasons” in mythology for why Orion ended up in the sky. One was because he was too boastful about how many animals he could kill — so he was put there to teach humility, since he and his dogs (Canis Major and Canis Minor) chase after animals in the sky but can’t catch them. Some say he died from a scorpion bite, and other legends say he was killed by his lover Artemis accidentally, when her brother Apollo tricked her to shooting an arrow at him.

Wide angle shot of Comet Lovejoy with the constellation Orion, showing rich fields of red nebula, star clouds and dark nebula with the bright green naked eye comet. Credit and copyright: Chris Schur.
Wide angle shot of Comet Lovejoy with the constellation Orion, showing rich fields of red nebula, star clouds and dark nebula with the bright green naked eye comet. Credit and copyright: Chris Schur.

Because Orion is on the celestial equator, Chandra adds, it is easy to see all over the world: “Ancient Indians saw the figure as a king who had been shot by an arrow (represented by the stars in Orion’s belt). Ancient Egyptians thought the stars in the belt represented the resting place of the soul of the god Osiris. The Arabs saw the constellation as the figure of a giant.”

The Orion’s belt stars

The three stars in the belt are Mintaka, Alnilam and Alnitak. According to an astronomer with the National Radio Astronomy Observatory, Ronald Maddlaena, these are the meanings of the three stars: Mintaka (on the west) means “belt”, Alnilam (in center) means “belt of pearls” and Altnitak (right) means “girdle.” The three range between 800 and 1,000 light-years from Earth.

The stars “probably formed at about the same time some ten million years ago from the molecular clouds astronomers have found in Orion,” wrote Maddalena.

In this image, the submillimetre-wavelength glow of the dust clouds is overlaid on a view of the region in the more familiar visible light, from the Digitized Sky Survey 2. The large bright cloud in the upper right of the image is the well-known Orion Nebula, also called Messier 42. Credit: ESO/Digitized Sky Survey 2
In this image, the submillimetre-wavelength glow of the dust clouds is overlaid on a view of the region in the more familiar visible light, from the Digitized Sky Survey 2. The large bright cloud in the upper right of the image is the well-known Orion Nebula, also called Messier 42. Credit: ESO/Digitized Sky Survey 2

Here are their properties compared to the Sun:

Mintaka: 20 times more massive and 7,000 times brighter. (Surface temperature 60,000 Fahrenheit.)

Alnilam: 20 times more massive and 18,000 times brigher. (Surface temperature 50,000 Fahrenheit.)

Alnitak: 20 times more massive and 10,000 times brighter. (Surface temperature 60,000 Fahrenheit).

To further blow your mind — these stars also have companion stars orbiting with them, so what you see from Earth with the naked eye isn’t necessarily what you always get.

We have written many articles about Orion for Universe Today. Here’s an article about the Orion Nebula, and another about the dust grains in the Orion Nebula. We’ve also done many episodes of Astronomy Cast about stars, such as this: Episode 12: Where Do Baby Stars Come From?

Posted on by Fraser Cain

Astronomy Cast – Episode 248: Carina Constellation

Time for another detailed look at a constellation; one of the most fascinating in the sky, but hidden to most of the northern hemisphere: Carina. Home to one of the most likely supernova candidates we know of: Eta Carinae. Let’s talk just about this constellation, how to find it, and what you can discover in and around it.

You can watch us record Astronomy Cast live every Monday at 12:00 pm PDT (3:00 pm EDT, 2000 GMT). Make sure you circle Fraser on Google+ to see it show up in the feed. You can also see it live over on our YouTube channel.

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