Constellation Archives

January 20, 2017June 2, 2017 by Tammy Plotner

The Carina Constellation

Argo Navis constellation map. Credit: Constellation Guide/Torsten Bronger

Welcome back to Constellation Friday! Today, in honor of the late and great Tammy Plotner, we will be dealing with the “keel of the ship”, the Carina 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, known as Argo Navis, would eventually be divided into three asterism – one of which became the southern constellations of Carina. Bordered by the Vela, Puppis, Pictor, Volans, Chamaeleon, Musca and Centaurus constellations, Carina is one of 88 modern constellations that are currently recognized by the IAU.

Name and Meaning:

The stellar southern constellation Carina is part of the ancient constellation known as Argo Navis. It is now abbreviated and represents the “Keel”. While Carina has no real mythological connection, since its stars weren’t visible to the ancient Greeks and Romans, it does have a fascinating history. Argo Navis (or simply Argo) was a large southern constellation representing the Argo, the ship used by Jason and the Argonauts in Greek mythology.

*Johannes Hevelius’ Argo Navis from Uranographia (1690). Credit: NASA/Chandra/Harvard University*

The Argo was built by the shipwright Argus, and its crew were specially protected by the goddess Hera. The best source for the myth is the Argonautica by Apollonius Rhodius. According to a variety of sources of the legend, the Argo was said to have been planned or constructed with the help of Athena.

According to other legends it contained in its prow a magical piece of timber from the sacred forest of Dodona, which could speak and render prophecies. After the successful journey, the Argo was consecrated to Poseidon in the Isthmus of Corinth. It was then translated into the sky and turned into the constellation of Argo Navis. The abbreviation for it was “Arg”, and the genitive was “Argus Navis”.

History of Observation:

Carina is the only one of Ptolemy’s list of 48 constellations that is no longer officially recognized as a constellation. In 1752, French astronomer Nicolas Louis de Lacaille subdivided Argo Navis into Carina (the keel of the ship), Puppis (the Poop deck), and Vela (the sails). Were this still considered to be a single constellation, it would be the largest of all, being larger than Hydra.

When Argo Navis was split, its Bayer designations were also split. Whereas Carina got the Alpha, Beta and Epsilon stars, Vela got Gamma and Delta, Puppis got Zeta, and so on. The constellation Pyxis occupies an area which in antiquity was considered part of Argo’s mast. However, Pyxis is not typically considered part of Argo Navis, and in particular its Bayer designations are separate from those of Carina, Puppis and Vela.

*Canopus (alpha Carinae), the brightest star in the Carina constellation and the second brightest star in the night sky. Credit: NASA*

Notable Features:

The Carina constellation consists of 9 primary stars and has 52 Bayer/Flamsteed designated stars. It’s alpha star, Canopus, is not only he brightest star in the constellation, but the second brightest in the night sky (behind Sirius). This F-type giant is 13,600 times brighter than our Sun, with an apparent visual magnitude of -0.72 and an absolute magnitude of -5.53.

The name is the Latinized version of the Greek name Kanobos, presumably derived from the pilot of the shop that took Menelaus of Sparta to Troy to retrieve Helen in The Iliad. It is also known by its Arabic name, Suhail, which is derived from the Arabic name for several bright stars.

Before the launching of the Hipparcos satellite telescope, distance estimates for the star varied widely, from 96 light years to 1200 light years. Had the latter distance been correct, Canopus would have been one of the most powerful stars in our galaxy. Hipparcos established Canopus as lying 310 light years (96 parsecs) from our solar system; this is based on a parallax measurement of 10.43 ± 0.53 mas.

The difficulty in measuring Canopus’ distance stemmed from its unusual nature. Canopus is too far away for Earth-based parallax observations to be made, so the star’s distance was not known with certainty until the early 1990s. Canopus is 15,000 times more luminous than the Sun and the most intrinsically bright star within approximately 700 light years.

*Sky as seen from central South America showing the approximate location of the new comet on August 19 in Puppis near the bright star Canopus. Credit: Stellarium*

For most stars in the local stellar neighborhood, Canopus would appear to be one of the brightest stars in the sky. Canopus is outshone by Sirius in our sky only because Sirius is far closer to the Earth (8 light years). Its surface temperature has been estimated at 7350 ± 30 K and its stellar diameter has been measured at 0.6 astronomical units 65 times that of the sun.

If it were placed at the centre of the solar system, it would extend three-quarters of the way to Mercury. An Earth-like planet would have to lie three times the distance of Pluto! Canopus is part of the Scorpius-Centaurus Association, a group of stars which share similar origins.

Next up is Miaplacidus (beta Carinae), an A-type subgiant located approximately 111 light years from Earth. It is the second brightest star in the constellation and the 29th brightest star in the sky. The star’s name means “placid waters”, which is derived from the combination of the Arabic word for waters (miyah) and the Latin word for placid (placidus).

Then there’s Eta Carinae, a luminous blue variable (LBV) binary star that is between 7,500 and 8,000 light years distant from Earth. The combined luminosity of this system is four million times that of our Sun, and the most massive star in the system has between 120 and 250 Solar Masses. It is sometimes known by its traditional names, Tseen She (“heaven’s altar” in Chinese) and Foramen.

Eta Carinae, one of the most massive stars known. Image credit: NASA — *Eta Carinae, one of the most massive stars in the known Universe. Credit: NASA*

Also, it is believed that Eta Carinae will explode in the not-too-distant future, and it will be the most spectacular supernovae humans have ever seen. This supernova (or hypernova) might even affect Earth, since the star is only 7,500 light years away, causing disruption to the upper layers of the atmosphere, the ozone layer, satellites, and spacecraft could be damaged and any astronauts who happen to be in space could be injured.

Avior (epsilon Carinae) is another double star system, consisting of a K0 III class orange giant and a hot hydrogen-fusing B2 V blue dwarf. With an apparent magnitude of 1.86 and is 630 light years distant, it is the 84th brightest star in the sky. The name Avior was assigned in the late 1930s by Her Majesty’s Nautical Almanac Office as a navigational aid, at the request of the Royal Air Force.

Aspidiske (aka. Iota Carinae) is a rare spectral type A8 Ib white supergiant located 690 light years from Earth. With a luminosity of 4,900 Suns (and seven Solar Masses), it is the 68th brightest star in the sky and is estimated to be around 40 million years old. It is known by the names Aspidiske, Turais and Scutulum, all diminutives of the word “shield,” (in Greek, Arabic and Latin, respectively).

Since the Milky Way runs through Carina, there are a large number of Deep Sky Objects associated with it. For instance, there’s the Carina Nebula (aka. the Eta Carinae Nebula, NGC 3372), a large nebula surrounding the massive stars Eta Carinae and HD 93129A. In addition to being four time as bright as the Orion Nebula (Messier 42), it is one of the largest diffuse nebulae known.

*The Eta Carinae Nebula, one of the largest nebulae in the known Universe. Credit: ESO, IDA, Danish 1.5 m, R. Gendler, J-E. Ovaldsen, C. Thöne, and C. Feron*

The nebula is between 6,500 and 10,000 light years from Earth, and has an apparent visual magnitude of 1.0. It contains several O-type stars (extremely luminous hot, bluish stars, which are very rare). The first recorded observation of this nebula was made by the French astronomer Nicolas Louis de Lacaille in 1751-52, who observed it from the Cape of Good Hope.

The Carina Nebula contains two smaller nebulae – the Homunculus Nebula and the Keyhole Nebula. The Keyhole Nebula – a small, dark cloud of dust and with bright filaments of fluorescent gas, was named by John Herschel in the 19th century. It is about seven light years in diameter, and appears contrasted against the bright nebula in the background.

The Homunculus Nebula (Latin for “Little Man”) is an emission nebula embedded within the Eta Carinae Nebula, immediately surrounding the star Eta Carinae. The nebula is believed to have formed after an enormous outburst from the star, which coincided with Eta Carinae becoming the second brightest star in the night sky. The light of this outburst was visible from Earth by 1841.

There’s also the Theta Carinae Cluster (aka. the Southern Pleiades, because of its resemblance to the Pleiades cluster. This open cluster was discovered by Lacaille in 1751, is located approximately 479 light years from Earth and is visible to the naked eye. The brightest star in the cluster, as the name indicates, is Theta Carinae, a blue-white dwarf.

*The Keyhole Nebula, part of the larger Carina Nebula. Credit: NASA/The Hubble Heritage Team (AURA, STScI)*

Then there’s the Wishing Well Cluster (aka. NGC 3532), an open cluster in Carina. Approximately 1,321 light years distant, the cluster is composed of about 150 stars that appear through a telescope like silver coins twinkling at the bottom of a wishing well. The cluster lies between the constellation Crux (the Southern Cross) and the False Cross asterism in Carina and Vela, and was first object observed by the Hubble Space Telescope in May 1990.

Finding Carina:

Carina is the 34th largest constellation in the sky, occupying an area of 494 square degrees. It lies in the second quadrant of the southern hemisphere (SQ2) and is visible at latitudes between +20° and -90° and is best seen during the month of March. Before you even begin with a telescope or binoculars, be sure to stop and just take a good look at Alpha Carinae – Canopus.

Canopus is essentially white when seen with the naked eye (though F-type stars are sometimes listed as “yellowish-white”). The spectral classification for Canopus is F0 Ia (Ia meaning “bright supergiant”), and such stars are rare and poorly understood; they are stars that can be either in the process of evolving to or away from red giant status. This in turn made it difficult to know how intrinsically bright Canopus is, and therefore how far away it might be.

Since the Milky Way runs through Carina, there are a large number of open clusters in the constellation, making it a binocular observing paradise. NGC 2516 is a magnitude 3.1 open cluster originally discovered by Abbe Lacaille in 1751 with a 1/2″ spyglass. This gorgeous 30 arc minute spread of stars is also known as Caldwell 96 and graces many observing lists, including the Astronomical League Open Cluster, Deep Sky and Southern Observing Clubs.

*Location of the Carina Constellation in the southern skies. Credit: IAU/Sky&Telescope magazine*

It is commonly known as the “Southern Beehive Cluster” (for it does resemble northern Messier 44) and it contains about 100 stars the brightest of which is an fifth magnitude red giant that lies near the center. As far as stellar age goes, this star cluster is very young – only about 140 million years old!

Now hop to IC 2602, popularly known as the “Southern Pleiades” for is resemblance to northern Messier 45. This galactic cluster contains more than 50 stars and is approximately 500 light years away from Earth. At its heart is blue-white star Theta Carinae, and it can be found by forming a triangle in the sky with Beta and Iota Carinae. With a stellar magnitude of 2.0, this object is easily seen as a nebulous patch to the unaided eye!

Another nebula that can been seen unaided but is better in binoculars is the Homunculus, an emission nebula surrounding the massive star Eta Carinae. The nebula is embedded within a much larger H II region, the Eta Carinae Nebula. Even though Eta Carinae is about 7,500 light-years away, structures only 10 billion miles across (about the diameter of our solar system) can be distinguished.

Dust lanes, tiny condensations, and strange radial streaks all appear with unprecedented clarity. Excess violet light escapes along the equatorial plane between the bipolar lobes. While there is relatively little dusty debris between the lobes down by the star; most of the blue light is able to escape. The lobes, on the other hand, contain large amounts of dust which absorb blue light, causing the lobes to appear reddish.

*The gas pillar in the Carina Nebula, known as the “Mystic Mountain”. Credit: NASA/ESA/M. Livio and the Hubble 20th Anniversary Team (STScI)*

The Eta Carinae Nebula, or NGC 3372 itself is fascinating. It is a hypergiant luminous blue variable star in the Carina constellation, one of the most massive stars yet discovered. Because of its mass and the stage of life, it is expected to explode in a supernova in the “near” future. Stars in the stellar mass class of Eta Carinae, with more than 100 times the mass of the Sun, produce more than a million times as much light as the Sun.

They are quite rare — only a few dozen in a galaxy as big as the Milky Way. They are assumed to approach (or potentially exceed) the Eddington limit, i.e., the outward pressure of their radiation is almost strong enough to counteract gravity. Stars that are more than 120 solar masses exceed the theoretical Eddington limit, and their gravity is barely strong enough to hold in their radiation and gas.

Now hop just three degrees away to NGC 3532 – known as the “Wishing Well Cluster”. This open star cluster is one of the jewels of the southern sky and is also referred to as Caldwell 91 and is on many observing lists. Want another? Try globular cluster NGC 2808, also known as Bennett 41. Beautiful NGC 2808 is a fine example of a symmetrical and strongly compressed globular cluster.

Viewable in binoculars and totally resolvable in a 6″ telescope, this is another of Dreyer’s remarkable objects described as very large extremely rich, and gradually reaching an extremely condensed status in the middle. NGC 2808 contains thousands of magnitude 13-15 stars!

*The NGC 2808 star cluster, Credit: NASA, ESA, A. Sarajedini (University of Florida) and G. Piotto (University of Padova)*

For double star fans, take on Epsilon Carinae, also known by the name Avior. Epsilon Carinae is a binary star located 630 light years away from our solar system. The primary component is a dying orange giant of spectral class K0 III, and the secondary is a hot hydrogen-fusing blue dwarf of class B2 V. The stars regularly eclipse each other, leading to brightness fluctuations on the order of 0.1 magnitudes.

Now try Upsilon Carinae – part of the Diamond Cross asterism in southern Carina. It’s name is Vathorz Prior, a name of Old Norse-Latin origin meaning “Preceding One of the Waterline”. Located approximately 1623 light years from Earth, the star system is made of two components. Upsilon Carinae A, is a white A-type supergiant with an apparent magnitude of +3.01 while its companion, Upsilon Carinae B, is a blue-white B-type giant 5 arc seconds away.

But no constellation would be complete without a true telescope challenge. Planetary nebula NGC 3211 (RA 10h 17m 50.4s Dec -62° 40´ 12″) heralds in at about 12th magnitude. For even more fun, try NGC 2867 (R.A. 09h 21m 25.3s Dec. -58° 18′ 40.7″). You’ll find it about a degree north/northeast of Iota. Iota Carinae. NGC 2867 may be no more than 2,750 years old.

Strangely, it is one of only a few dozen objects known to have a Wolf-Rayet star (type WC6) as its central star. NGC 2867 was discovered by John Herschel from Felhausen observatory at the Cape of Good Hope on April’s Fools Day, 1834 – appropriate since Herschel was almost fooled into thinking it was a new planet. Its size and appearance were certainly planet-like and it was only after careful checking that Herschel was convinced it was a nebula.

*The NGC 3247 nebur. Credit NASA/JPL-Caltech/E. Churchwell (University of Wisconsin)*

Now try NGC 3247 (RA 10 : 25.9 Dec -57 : 56 ). This is a very cool, very small galactic cluster with associated nebulosity. At around magnitude 8, you won’t find the rich little cluster much of a problem, but use minimal magnifcation to appreciate the true field!

While at the telescope, also look up NGC 3059 (9 : 50.2 Dec -73 : 55). Now, we’ve got a spiral galaxy cutting its way through the dust of the Milky Way! With an apparent magnitude of 12, and a 3.2 arc minute diameter, this barred spiral galaxy is going to present a nice, unique challenge to southern hemisphere observers.

There are myriad other things to look at in Carina as well, so don’t see this lovely constellation short! There is also a meteor shower associated with the constellation of Carina, too. The Eta Carinids are a lesser known meteor shower lasting from January 14 to 27 each year. The activity peaks on or about January 21. It was first discovered in 1961 in Australia. Roughly two to three meteors occur per hour at its maximum. It gets its name from the radiant which is close to the nebulous star Eta Carinae.

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.

Source:

September 12, 2016September 17, 2016 by Bob King

The Big Dipper in the Year 92,000

Stellar motions distort the future sky. Map: Bob King, Source: Stellarium

If we could transport Ptolemy, a famous astronomer who lived circa 90 – 168 A.D. in Alexandria, Egypt, he would have noticed the shift in position of Arcturus, Sirius and Aldebaran since his time. Everything else would appear virtually unchanged. — If we could transport **Ptolemy**, a famous astronomer who lived circa 90 – 168 A.D. in Alexandria, Egypt, he would have noticed the shift in position of Arcturus, Sirius and Aldebaran since his time. Everything else would appear virtually unchanged.

You go out and look at the stars year after year and never see any of them get up and walk away from their constellations. Take a time machine back to the days of Plato and Socrates and only careful viewing would reveal that just three of the sky’s naked eye stars had budged: Arcturus, Sirius and Aldebaran. And then only a little. Their motion was discovered by Edmund Halley in 1718 when he compared the stars’ positions then to their positions noted by the ancient Greek astronomers. In all three cases, the stars had moved “above a half a degree more Southerly at this time than the Antients reckoned them.”

NGC 4414 is a spiral galaxy that resembles our own Milky Way. I've drawn in the orbits of several stars. Both disk and halo stars orbit about the center but halo stars describe long elliptical orbits. When they plunge through the disk, if they happen to be relatively nearby as is Arcturus, they'll appear to move relatively quickly across the sky. Credit: NASA/ESA — NGC 4414 is a spiral galaxy that resembles our own Milky Way. I’ve drawn in the orbits of several stars. Both disk and halo stars orbit about the center, but halo stars describe long elliptical orbits that take them well beyond the disk. When a star plunges through the disk, if it happens to be relatively nearby as in the case of Arcturus, the star will appear to move relatively quickly across the sky. Both distance and the type of orbit a star has can affect how fast it moves from our perspective. Credit: NASA/ESA with orbits by the author

Stars are incredibly far away. I could throw light years around like I often do here, but the fact is, you can get a real feel for their distance by noting that during your lifetime, none will appear to move individually. The gems of the night and our sun alike revolve around the center of the galaxy. At our solar system’s distance from the center — 26,000 light years or about halfway from center to edge — it takes the sun about 225 million years to make one revolution around the Milky Way.

That’s a LONG time. The other stars we see on a September night take a similar length of time to orbit. Now divide the average lifetime of some 85 years into that number, and you’ll discover that an average star moves something like .00000038% of its orbit around the galactic center every generation. Phew, that ain’t much! No wonder most stars don’t budge in our lifetime.

This graphic, compiled using SkyMap software created by Chris Marriott, shows the motion of Arcturus over — This graphic, made using SkyMap software created by Chris Marriott, shows the motion of Arcturus over a span of 8,000 years.

Sirius, Aldebaran and Arcturus and several other telescopic stars are close enough that their motion across the sky becomes apparent within the span of recorded history. More powerful telescopes, which expand the scale of the sky, can see a great many stars amble within a human lifetime. Sadly, our eyes alone only work at low power!

Precession of Earth's axis maintains it usual 23.5 degree tilt, but this causes the axis to describe a circle in the sky like a wobbling top. Credit: Wikimedia Commons — Precession of Earth’s axis maintains its usual 23.5 degree tilt, but this causes the axis to describe a circle in the sky like a wobbling top. The photo is an animation that repeats 10 seconds, so hang in there. Credit: Wikimedia Commons

But we needn’t invest billions in building a time machine to zing to the future or past to see how the constellation outlines become distorted by the individual motions of the stars that compose them. We already have one! Just fire up a free sky charting software program like Stellarium and advance the clock. Like most such programs, it defaults to the present, but let’s look ahead. Far ahead.

If we advance 90,000 years into the future, many of the constellations would be unrecognizable. Not only that, but more locally, the precession of Earth’s axis causes the polestar to shift. In 2016, Polaris in the Little Dipper stands at the northernmost point in the sky, but in 90,000 years the brilliant star Vega will occupy the spot. Tugs from the sun and moon on Earth’s equatorial bulge cause its axis to gyrate in a circle over a period of about 26,000 years. Wherever the axis points defines the polestar.

I advanced Stellarium far enough into the future to see how radically the Big Dipper changes shape over time. Notice too that Vega will be the polestar in that distant era. Map: Bob King, Source: Stellarium

Take a look at the Big Dipper. Wow! It’s totally bent out of shape yet still recognizable. The Pointer Stars no longer quite point to Polaris, but with some fudging we might make it work. Vega stands near the pole, and being much closer to us than the rest of Lyra’s stars, has moved considerably farther north, stretching the outline of the constellation as if taffy.

Now let's head backwards in time 92,000 years to 90,000 B.C. The Dipper then was fairly unrecognizable, with both Vega and Arcturus near the pole. Map: Bob King , Source: Stellarium — Now let’s head backwards in time 92,000 years to 90,000 B.C. The Dipper then was fairly unrecognizable, with both Vega and Arcturus near the pole. Map: Bob King , Source: Stellarium

Time goes on. We look up at the night sky in the present moment, but so much came before us and much will come after. Constellations were unrecognizable in the past and will be again in the future. In a fascinating discussion with Michael Kauper of the Minnesota Astronomical Society at a recent star party, he described the amount of space in and between galaxies as so enormous that “we’re almost not here” in comparison. I would add that time is so vast we’re likewise almost not present. Make the most of the moment.

March 7, 2016March 7, 2016 by Tammy Plotner

Messier 6 – The Butterfly Cluster

M6 open cluster (NGC 6405). Credit: Ole Nielsen

Welcome back to Messier Monday! We continue our tribute to our dear friend, Tammy Plotner, by looking at Messier 6, otherwise known as NGC 6405 and the Butterfly Cluster. Enjoy!

In the late 18th century, Charles Messier was busy hunting for comets in the night sky, and noticed several “nebulous” objects. After initially mistaking them for the comets he was seeking, he began to compile a list of these objects so other astronomers would not make the same mistake. Known as the Messier Catalog, this list consists of 100 objects, consisting of distant galaxies, nebulae, and star clusters.

This Catalog would go on to become a major milestone in the history of astronomy, as well as the study of Deep Sky Objects. Among the many famous objects in this catalog is M6 (aka. NGC 6405), an open cluster of stars in the constellation of Scorpius. Because of its vague resemblance to a butterfly, it is known as the Butterfly Cluster.

Continue reading “Messier 6 – The Butterfly Cluster”

March 4, 2016December 2, 2016 by Tammy Plotner

The Aquarius Constellation

Aquarius the "Water Bearer" is a large but faint constellation in the Southern sky. Credit: Stellarium

Welcome back to Constellation Friday! Today, we will be dealing with one of the best-known constellations, that “watery” asterism and section of the sky known as Aquarius. Cue the soundtrack from Hair!

In the 2nd century CE, Greek-Egyptian astronomer Claudius Ptolemaeus (aka. Ptolemy) compiled a list of all the-then known constellations. This work (known as the Almagest) would remain the definitive guide to astronomy and astrology for over a thousand years. Among the 48 constellations listed in this book was Aquarius, a constellation of the zodiac that stretches from the celestial equator to the southern hemisphere.

Also known as the “Water Carrier”, Aquarius is bordered by Pegasus, Equuleus and Delphinus at the north, Aquila to the west, Capricornus to the south-west, Piscis Austrinus and Sculptor to the south, Cetus to the east and Pisces to the north-east. Today, it is one of the 88 constellations recognized by the International Astronomical Union (IAU), and is perhaps the most referenced and recognized of all the constellation.

Continue reading “The Aquarius Constellation”

February 26, 2016June 2, 2017 by Tammy Plotner

The Apus Constellation

The constellation Apus, located in the Southern Hemisphere. Credit: astropixels.com

Welcome back to Constellation Friday! Today, we will be dealing with the beautiful bird-of-paradise itself, the Apus constellation!

The Southern Hemisphere is replete with beautiful stars and constellations, enough to keep a stargazing enthusiast busy for a lifetime. For countless centuries, the indigenous peoples of South America, South Africa, Australia and the South Pacific have looked up at these stars and drawn inspiration. However, to European astronomers, they remained uncharted and unknown until the 16th century.

It was during this time that Flemish astronomer Petrus Plancius designated twelve constellations, using asterisms found in the southern skies. One such constellation was Apus, a faint constellation in the southern sky that is named for the bird-of-paradise – a beautiful bird that is indigenous to the South Pacific. Today, it is one of the 88 constellations defined by the International Astronomic Union (IAU).

Name and Meaning:

The name Apus is derived from Greek word apous, which literally means “no feet”. The name applies to a species of bird that is indigenous to Indonesia, Papua New Guinea, and Eastern Australia (which was believed at one time to have no feet). Its original name on Plancius’ charts was “Apis Indica” – the Latin term for “Indian Bee” (presumably an error for “avis”, which means bird).

Because of this error, the bordering constellation of Musca was later separated and renamed. The neighboring constellations to Apus are Ara, Chamaeleon, Circinus, Musca, Octans, Pavo, and Triangulum Australe.

*The Constellation Apus. Credit: iau.org*

History of Observation:

This faint southern constellation of Apus was one of the original twelve created by Plancius, based on observations provided by Pieter Dirkszoon Keyser and Frederick de Houtman – two Dutch explorers/navigators who mapped the southern sky around Australia between 1595 and 1597.

It was included on a celestial globe published in 1597 or 1598 in Amsterdam by Plancius and his associate, Flemish cartographer and engraver Jodocus Hondius. After it’s introduction on Plancius’ globe, it also appeared in Uranometria, a star atlas published by Johann Bayer – a German celestial catrographer – in 1603.

Here, it appeared under the name “Apis Indica”. It also grouped with the other members of the “Johann Bayer family” of constellations, all of which appeared in Uranometria. These include Chamaeleon, Dorado, Grus, Hydrus, Indus, Musca, Pavo, Phoenix, Tucana, and Volans. The constellation also appears as part of the Chinese constellations, where it is known as the “Little Wonder Bird”.

In the 17th century, Ming Dynasty astronomer Xu Guangqi adapted the European southern hemisphere constellations when producing The Southern Asterisms. Combining Apus with some of the stars in Octans, he designated the stars in this area of the night sky into the constellation known as Yìquè (“Exotic Bird”). In 1922, Apus was included by the International Astronomical Union in the list of 88 constellations.

*The southern constellation Apus and neighboring Deep Sky Objects. Credit: absoluteaxarquia.com*

Notable Features:

Within the Apus constellation, there are 39 stars that are brighter than or equal to apparent magnitude 6.5. The most notable of these is Alpha Apodis. an orange giant star with a magnitude of 3.8, located roughly 411 light years away from Earth. Beta Apodis is also an orange giant, with a magnitude of 4.2. and located 158 light years from Earth. And Gamma Apodis , another orange giant, has a magnitude of 3.9 and is located 160 light years away.

Delta Apodis is a binary star system consisting of a red giant and an orange giant. Delta¹ has a magnitude of 4.7 and is located 765 light years away, while Delta² has a magnitude of 5.3 and is located 663 light years away. Then there is Theta Apodis, a variable red giant star with a maximum magnitude of 4.8 and a minimum of 6.1 that is located 328 light years away.

NO Apodis is a red giant that varies between magnitudes 5.71 and 5.95 and is located around 883 light-years away from Earth. This star shines with a luminosity that is approximately 2059 times greater than our Sun’s and has a surface temperature of 3568 K.

Apus is also home to a few Deep Sky Objects. These include the IC 4499 loose globular cluster (shown below), which is located in the medium-far galactic halo and has an apparent magnitude of 10.6. This object is rather unique in that its metallicity readings indicate that it is younger than most other globular clusters in the region.

This new NASA/ESA Hubble Space Telescope image shows the globular cluster IC 4499. Globular clusters are big balls of old stars that orbit around their host galaxy. It has long been believed that all the stars within a globular cluster form at the about same time, a property which can be used to determine the cluster's age. For more massive globulars however, detailed observations have shown that this is not entirely true — there is evidence that they instead consist of multiple populations of stars born at different times. One of the driving forces behind this behaviour is thought to be gravity: more massive globulars manage to grab more gas and dust, which can then be transformed into new stars. IC 4499 is a somewhat special case. Its mass lies somewhere between low-mass globulars, which show a single generation build-up, and the more complex and massive globulars which can contain more than one generation of stars. By studying objects like IC 4499 astronomers can therefore explore how mass affects a cluster's contents. Astronomers found no sign of multiple generations of stars in IC 4499 — supporting the idea that less massive clusters in general only consist of a single stellar generation. Hubble observations of IC 4499 have also helped to pinpoint the cluster's age: observations of this cluster from the 1990s suggested a puzzlingly young age when compared to other globular clusters within the Milky Way. However, since those first estimates new Hubble data been obtained, and it has been found to be much more likely that IC 4499 is actually roughly the same age as other Milky Way clusters at approximately 12 billion years old. Credit: ESA/NASA/HST — *NASA/ESA Hubble Space Telescope image of the globular cluster IC 4499, located in the Apus constellation. Credit: ESA/NASA/HST*

Then there’s NGC 6101, a 14th mangitude globular cluster located seven degree north of Gamma Apodis. Last, there is the spiral galaxy IC 4633, which is very faint due to its location well within the Milky Way’s nebulous disc.

Finding Apus:

For binoculars, take a look at Alpha Apodis. This 3.8 magnitude star is located 411 light years away from Earth. Now move on to Delta. It is a wide double star which is two orange 5th-magnitude members separated by 103 arc seconds and an easy split. Or try observing Theta – its a variable star whose brightness ranges from magnitude 4.8 to 6.1 in a period of 109 days.

For telescopes, take a look at more difficult binary star Kappa-1 Apodis. The brightest component of this disparate pair has a magnitude of 5.4 and the companion is 12th magnitude, 27 arcseconds away. Need more? Then turn your gaze towards Kappa-2 only 0.63 degrees from Kappa-1. Kappa-1 Apodis is a binary star approximately 1020 light years from Earth. The primary component, Kappa-1 Apodis A, is a blue-white B-type subgiant with a mean apparent magnitude of +5.40. It is classified as a Gamma Cassiopeiae type variable star and its brightness varies from magnitude +5.43 to +5.61. The companion star, Kappa-1 Apodis B, is a 12th magnitude orange K-type subgiant. It is 27 arc seconds from the primary.

For larger telescopes, wander off and look at NGC 6101 located about seven degrees north of Gamma. Here we have a small, 14th magnitude globular cluster! If you’re really good you can try for spiral galaxy IC 4633. It’s so faint it doesn’t even have a magnitude listing!

We have written many interesting articles about the constellation here at Universe Today. Here is What Are The Constellations?, Triangulum Australe, 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 Apus and Constellation Families.

February 12, 2016April 26, 2016 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”

February 5, 2016December 10, 2021 by Tammy Plotner

What Are The Constellations?

milky way constellations — Full panoramic view of the constellations near the Milky Way by Matt Dieterich

What comes to mind when you look up at the night sky and spot the constellations? Is it a grand desire to explore deep into space? Is it the feeling of awe and wonder, that perhaps these shapes in the sky represent something? Or is the sense that, like countless generations of human beings who have come before you, you are staring into the heavens and seeing patterns? If the answer to any of the above is yes, then you are in good company!

While most people can name at least one constellation, very few know the story of where they came from. Who were the first people to spot them? Where do their names come from? And just how many constellations are there in the sky? Here are a few of the answers, followed by a list of every known constellation, and all the relevant information pertaining to them.

Definition:

A constellation is essentially a specific area of the celestial sphere, though the term is more often associated with a chance grouping of stars in the night sky. Technically, star groupings are known as asterisms, and the practice of locating and assigning names to them is known as asterism. This practice goes back thousands of years, possibly even to the Upper Paleolithic. In fact, archaeological studies have identified markings in the famous cave paintings at Lascaux in southern France (ca. 17,300 years old) that could be depictions of the Pleiades cluster and Orion’s Belt.

There are currently 88 officially recognized constellations in total, which together cover the entire sky. Hence, any given point in a celestial coordinate system can unambiguously be assigned to a constellation. It is also a common practice in modern astronomy, when locating objects in the sky, to indicate which constellation their coordinates place them in proximity to, thus conveying a rough idea of where they can be found.

Closeup of one section of the cave painting at the Lascaux cave complex, showing what could be Pleiades and Orion's Belt. Credit: ancient-wisdom.com — *Closeup of the Lascaux cave paintings, showing a bull and what could be the Pleiades Cluster (over the right shoulder) and Orion’s Belt (far left). Credit: ancient-wisdom.com*

The word constellation has its roots in the Late Latin term constellatio, which can be translated as “set of stars”. A more functional definition would be a recognizable pattern of stars whose appearance is associated with mythical characters, creatures, or certain characteristics. It’s also important to note that colloquial usage of the word “constellation” does not generally differentiate between an asterism and the area surrounding one.

Typically, stars in a constellation have only one thing in common – they appear near each other in the sky when viewed from Earth. In reality, these stars are often very distant from each other and only appear to line up based on their immense distance from Earth. Since stars also travel on their own orbits through the Milky Way, the star patterns of the constellations change slowly over time.

History of Observation:

It is believed that since the earliest humans walked the Earth, the tradition of looking up at the night sky and assigning names and characters to them existed. However, the earliest recorded evidence of asterism and constellation-naming comes to us from ancient Mesopotamia, and in the form of etchings on clay tablets that are dated to around ca. 3000 BCE.

However, the ancient Babylonians were the first to recognize that astronomical phenomena are periodic and can be calculated mathematically. It was during the middle Bronze Age (ca. 2100 – 1500 BCE) that the oldest Babylonian star catalogs were created, which would later come to be consulted by Greek, Roman and Hebrew scholars to create their own astronomical and astrological systems.

*Star map showing the celestial globe of Su Song (1020-1101), a Chinese scientist and mechanical engineer of the Song Dynasty (960-1279). Credit: Wikipedia Commons*

In ancient China, astronomical traditions can be traced back to the middle Shang Dynasty (ca. 13th century BCE), where oracle bones unearthed at Anyang were inscribed with the names of star. The parallels between these and earlier Sumerian star catalogs suggest they did no arise independently. Astronomical observations conducted in the Zhanguo period (5th century BCE) were later recorded by astronomers in the Han period (206 BCE – 220 CE), giving rise to the single system of classic Chinese astronomy.

In India, the earliest indications of an astronomical system being developed are attributed to the Indus Valley Civilization (3300–1300 BCE). However, the oldest recorded example of astronomy and astrology is the Vedanga Jyotisha, a study which is part of the wider Vedic literature (i.e. religious) of the time, and which is dated to 1400-1200 BCE.

By the 4th century BCE, the Greeks adopted the Babylonian system and added several more constellations to the mix. By the 2nd century CE, Claudius Ptolemaus (aka. Ptolemy) combined all 48 known constellations into a single system. His treatise, known as the Almagest, would be used by medieval European and Islamic scholars for over a thousand years to come.

Between the 8th and 15th centuries, the Islamic world experienced a burst of scientific development, reaching from the Al-Andus region (modern-day Spain and Portugal) to Central Asia and India. Advancements in astronomy and astrology closely paralleled those made in other fields, where ancient and classical knowledge was assimilated and expanded on.

*The Northern Constellations. Credit: Bodel Nijenhuis Collection/Leiden University Library*

In turn, Islamic astronomy later had a significant influence on Byzantine and European astronomy, as well as Chinese and West African astronomy (particularly in the Mali Empire). A significant number of stars in the sky, such as Aldebaran and Altair, and astronomical terms such as alidade, azimuth, and almucantar, are still referred to by their Arabic names.

From the end of the 16th century onward, the age of exploration gave rise to circumpolar navigation, which in turn led European astronomers to witness the constellations in the South Celestial Pole for the first time. Combined with expeditions that traveled to the Americas, Africa, Asia, and all other previously unexplored regions of the planet, modern star catalogs began to emerge.

IAU Constellations:

The International Astronomical Union (IAU) currently has a list of 88 accepted constellations. This is largely due to the work of Henry Norris Russell, who in 1922, aided the IAU in dividing the celestial sphere into 88 official sectors. In 1930, the boundaries between these constellations were devised by Eugène Delporte, along vertical and horizontal lines of right ascension and declination.

The IAU list is also based on the 48 constellations listed by Ptolemy in his Almagest, with early modern modifications and additions by subsequent astronomers – such as Petrus Plancius (1552 – 1622), Johannes Hevelius (1611 – 1687), and Nicolas Louis de Lacaille (1713 – 1762).

The modern constellations. color-coded by family, with a dotted line denoting the ecliptic. Credit: NASA/Scientific Visualization Studio — *The modern constellations, color-coded by family, with a dotted line denoting the ecliptic. Credit: NASA/Scientific Visualization Studio*

However, the data Delporte used was dated to the late 19th century, back when the suggestion was first made to designate boundaries in the celestial sphere. As a consequence, the precession of the equinoxes has already led the borders of the modern star map to become somewhat skewed, to the point that they are no longer vertical or horizontal. This effect will increase over the centuries and will require revision.

Not a single new constellation or constellation name has been postulated in centuries. When new stars are discovered, astronomers simply add them to the constellation they are closest to. So consider the information below, which lists all 88 constellations and provides information about each, to be up-to-date! We even threw in a few links about the zodiac, its meanings, and dates.

Enjoy your reading!

-A

-B

-C

-D

-E

-F

Fornax

-G

-H

-I

Indus

-L

-M

-N

Norma

-O

-P

-R

Reticulum

-S

-T

-U

-V

November 15, 2015December 23, 2015 by Bob King

Sweet Sights for November Nights

A pretty crescent moon will be the first thing you'll see appear in the sky tonight. Look southwest shortly after sunset to spot it. Source: Stellarium

Clear night ahead? Let’s see what’s up. We’ll start close to home with the Moon, zoom out to lonely Fomalhaut 25 light years away and then return to our own Solar System to track down the 7th planet. Even before the sky is dark, you can’t miss the 4-day-old crescent Moon reclining in the southwestern sky. Watch for it to wax to a half-moon by Thursday as it circles Earth at an average speed of 2,200 mph (3,600 km/hr). That fact that it orbits Earth means that the angle the Moon makes with the sun and our planet constantly varies, the reason for its ever-changing phase.

You'll see two and possibly three lunar "seas" tonight (Nov. 15). Only a portion of Mare Tranquilliitatis (Seas of Tranquility) is exposed. The large crater Janssen, 118 miles wide and 1.8 miles deep, is visible in binoculars. Credit: Virtual Moon Atlas / Legrande and Chevalley — You’ll see two and possibly three lunar “seas” tonight (Nov. 15). Only a portion of Mare Tranquilliitatis (Seas of Tranquility) is exposed. The large crater Janssen, 118 miles wide and 1.8 miles deep, is visible in binoculars. Credit: Virtual Moon Atlas / Legrande and Chevalley

With the naked eye you’ll be able to make two prominent dark patches within the crescent — Mare Crisium (Sea of Crises) and Mare Fecunditatis (Sea of Fecundity). Each is a vast, lava-flooded plain peppered with thousands of craters , most of which require a telescope to see. Not so Janssen. This large, 118-mile-wide (190-km) ring will be easy to pick out in a pair of seven to 10 power binoculars. Janssen is named for 19th century French astronomer Pierre Janssen, who was the first to see the bright yellow line of helium in the sun’s spectrum while observing August 1868 total solar eclipse.

Piscis Austrinus, the Southern Fish, has but one bright star, 1st magnitude Fomalhaut. It shines all by its lonesome in the south around 7 p.m. local time at mid-month. The star is located only 25 light years from Earth. Source: Stellarium

English scientist Norman Lockyer also observed the line later in 1868 and concluded it represented a new solar element which he named “helium” after “helios”, the Greek word for sun. Helium on Earth wouldn’t be discovered for another 10 years, making this party-balloon gas the only element first discovered off-planet!

See the fish now? Greek mythology tells us that Piscis Austrinus is the "Great Fish", the parent of the two fish in the zodiacal constellation of Pisces the Fish. Source: Stellarium — See the fish now? Greek mythology tells us that Piscis Austrinus is the “Great Fish”, the parent of the two fish in the zodiacal constellation of Pisces the Fish. Source: Stellarium

Directing your gaze south around 7 o’clock, you’ll see a single bright star low in the southern sky. This is Fomalhaut in the dim constellation of Piscis Austrinus, the Southern Fish. The Arabic name means “mouth of the fish”. If live under a dark, light-pollution-free sky, you’ll be able to make out a loop of faint stars vaguely fish-like in form. Aside from being the only first magnitude star among the seasonal fall constellations, Fomalhaut stands out in another way — the star is ringed by a planet-forming disk of dust and rock much as our own Solar System was more than 4 billion years ago.

The planet Fomalhaut b orbits Fomalhaut inside a circumstellar disk of dust and rock, taking about 1,700 years to orbit. Brilliant Fomalhaut, represented by the small, white dot, has been masked from view, so astronomers could photograph the much fainter disk. Credit: NASA / ESA / Hubble Space Telescope

Within that disk is a new planet, Fomalhaut b, with less than twice Jupiter’s mass and enshrouded either by a cloud of dusty debris or a ring system like Saturn. Fomalhaut b has the distinction of being the first extrasolar planet ever photographed in visible light. The plodding planet takes an estimated 1,700 years to make one loop around Fomalhaut, with its distance from its parent star varying from about 50 times Earth’s distance from the sun at closest to 300 times that distance at farthest.

Shoot a diagonal across the Square of Pegasus to 4th magnitude Delta Piscium. Point your binoculars here and slide east to 4th magnitude Epsilon and 2° south to the planet Uranus shines at magnitude +5.7 and can be glimpsed with the naked eye from a dark sky site. Time shown is around 7 p.m. local time. See detailed map below. Source: Stellarium

Next, we move on to one of the more remote planets in our own solar system, Uranus. The 7th planet from the sun, Uranus reached opposition — its closest to Earth and brightest appearance for the year — only a month ago. It’s well-placed for viewing in Pisces the Fish after nightfall high in the southeastern sky below the prominent sky asterism, the Great Square of Pegasus.

Wide-field binocular view of Uranus' travels now through next April. I've labeled two stars near the planet with their magnitudes - 5.5 and 6.0 - which are similar to Uranus in brightness, so you don't confuse them with the planet. The others are naked eye stars in Pisces. Source: Chris Mariott's SkyMap — Wide-field binocular view of Uranus’ travels now through next April. I’ve labeled several stars near the planet with their magnitudes, which are similar in brightness to Uranus, so you’ll know to tell them apart from the planet. The others are naked eye stars in Pisces. Source: Chris Mariott’s SkyMap

A telescope will tease out its tiny, greenish disk, but almost any pair of binoculars will easily show the planet as a star-like point of light slowly marching westward against the starry backdrop in the coming weeks. Check in every few weeks to watch it move first west, in retrograde motion, and then turn back east around Christmas. For those with 8-inch and larger telescopes who love a challenge, use this Uranian Moon Finder to track the planet’s two brightest moons, Titania and Oberon, which glimmer weakly around 14th magnitude.

We’ve barely scratched the surface of the vacuum with these offerings; they’re just a few of the many highlights of mid-November nights that also include the annual Leonid meteor shower, which peaks Tuesday and Wednesday mornings (Nov. 17-18). So much to see!

October 23, 2015December 23, 2015 by David Dickinson

Seeing Starspots: The Curious Case of XX Trianguli

Ever wonder what happens on the surface of other stars?

An amazing animation was released this week by astronomers at the Leibniz Institute for Astrophysics (AIP) in Potsam Germany, showing massive sunspot activity on the variable star XX Trianguli (HD 12545). And while ‘starspot’ activity has been seen on this and other stars before, this represents the first movie depicting the evolution of stellar surface activity beyond our solar system.

“We can see our first application as a prototype for upcoming stellar cycle studies, as it enables the prediction of a magnetic-activity cycle on a dramatically shorter timescale than usual,” says Leibniz Institute for Astrophysics Potsdam astronomer Andreas Kunstler in a recent press release.

The images were the result of a long term analysis of the star carried out using the twin STELLA (STELLar Activity) robotic telescopes based on Tenerife in the Canary Islands. The spectroscopic data was gathered over a period of six years, and this video demonstrates that, while other stars do indeed have sunspot cycles similar to our Sun, those of massive stars such as XX Tri are much more intense than any we could imagine here in our own solar system.

Image credit: Leibniz Institute for Astrophysics Potsdam (AIP) — STELLA on the hunt. Image credit:

Even the largest and closest of stars have a minuscule angular diameter –measured in milliarcseconds (mas, our 1/1,000ths of an arc second)—in size. For example, we know from lunar occultation timing experiments that the bright star Antares at 550 light years distant and 5 times the radius of our Sun is about 41 mas in size. At an estimated 910 to 1,500 light years distant and 10 times the radius of our Sun, XX Tri is probably comparable, at about 20 mas in size.

That’s tiny from our perspective, though the massive starspot depicted must be truly gigantic to see up close.

To image something on that scale, astronomers use a technique known as Doppler tomography gathered from high-resolution spectra. Over said six year span covering a period from July 2006 to April 2012, 667 viable spectra were gathered, covering 86 total rotational periods for the star. Incidentally, that’s not much longer than the average equatorial rotational period of our Sun—remember, as a ball of gas, the rotational period of our Sun varies with solar latitude—at about 22 days.

Our relatively sedate host star. image credit: Dave Dickinson — Our relatively sedate host star. Image credit: Dave Dickinson

The views compiled by the team show a pole facing, Mercator projection, and a spherical ‘real view’ of the star. Of course, to see XX Tri up close would be amazing, if a not a little intimidating with those massive, angry spots dappling its surface.

Watch the animation, and you can see the changing morphology of the spots, as they decay, merge and defuse again. Just how permanent is that massive pole spot? Why are we seeing spots across the pole of a star like XX Tri at all, something we never see on the Sun? Do other stars follow something analogous to Spörer’s Law and their own version of the 11-year sunspot cycle that we see on Sol?

Capabilities such as those demonstrated by STELLA may soon crack these questions wide open. Composed of two 1.2 meter robotic telescopes jointly operated by the Institute for Astrophysics at Potsdam and the Instituto de Astrofísica de Canarias (IAC), STELLA combines the capability of a wide-field photometric imager with that of a high-resolution spectrograph, ideal for this sort of analysis of remote stellar surfaces.

A diagram featuring the twin STELLA instruments. Image credit: Leibniz Institute for Astrophysics Potsdam (AIP)

Hey, here’s a crazy idea: turn STELLA loose on KIC 8462852 and see if the hypothesized ‘exo-comets’ or ‘alien mega-structures’ turn up… though it weighs in much smaller than XX Tri at 1.4x solar masses, KIC 8462852 is also about 1,400 light years distant, perhaps just doable using high resolution spectroscopy…

Want to see XX Tri for yourself? An RS Canum Venaticorum variable orange giant star (spectral type K0 III) located in the constellation of Triangulum the Triangle, XX Tri shines at magnitude +8.5 and varies over about half a magnitude in brightness. Its coordinates are:

Right Ascension: 2 hours 3 minutes 47 seconds

Declination: 35 North 35 minutes 29 seconds

The more we learn about other stars, the more we understand about how to live with our very own sometimes placid, sometimes tempestuous host star.

Read more about the curious case of XX Trianguli:

–On the Starspot Temperature of HD 12545

–HD 124545: A Study in Spottedness

–Spot evolution on the Star XX Triangulum (sic)

Does XX Trianguli look familiar? That might be because it was featured as the Astronomy Picture of the Day as ‘imaged’ by the Coude Feed Telescope on Kitt Peak way back when on November 2nd, 2003.

September 29, 2015December 23, 2015 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
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

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

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.”

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

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