Posted on by Fraser Cain

Astrophoto: A New Star in Ophiucus by John Chumack

RS Ophicuchi by John Chumack
On February 12, Universal time, two Japanese observers, Kiyotaka Kanai and Hiroaki Narumi, noticed that a star normally too dim to be seen by the unaided eye in the constellation of Ophiucus had suddenly grown much brighter. It was now about as visible as the star in the handle of the Little Dipper that is nearest Polaris, the northern pole star. The star is named RS Ophicuchi and it has done this before in 1898, 1933, 1945 (this date is suspected), 1958, 1967 and 1985.

RS Ophicuchi is a double star – one’s a red giant the other’s a white dwarf. Material from the red giant is constantly being pulled toward the dwarf where it accumulates to form a flat, ring-like disk that reaches to its surface. Over time the pressure within and temperature of the accretion disk increases until it’s enough to ignite a thermonuclear explosion of unimaginable proportions. We see that flash of brilliance, this one was located three thousand light years in the distance, as a nova.

Novas only happen in stellar pairs and represent the aches and pains of older stars. Unlike supernova, which occur in single, massive stars, novas seldom result in the annihilation of either.

As of last weekend, the brilliance of the nova had started to fade and will continue to do so gradually for quite some time. During the 1985 episode, it took almost a year and a half before the stars had returned to their normal faintness as seen here on Earth. Of course, now that the previous material has been destroyed, new material will slowly start to re-accumulate on the dwarf star and begin a new cycle that will lead up to the next explosion.

John Chumack took this picture of RS Ophicuchi, three days after its discovery from a remotely controlled observatory in New Mexico. John took sixteen 30 second pictures then combined them to create this full color image that is the equivalent of a single eight minute exposure. This image covers a sky area that is approximately four full moons wide using a Takahashi Sky90 telescope and a SBIG three mega-pixel camera.

Do you have photos you’d like to share? Post them to the Universe Today astrophotography forum or email them, and we might feature one in Universe Today.

Written by R. Jay GaBany

Posted on by Fraser Cain

What’s Up This Week – February 27 – March 5, 2006

What's Up 2006

Download our free “What’s Up 2006” ebook, with entries like this for every day of the year.

AE Aurigaey. Image credit: T.A. Rector and B.A. Wolpa/NOAO/AURA/NSF. Click to enlarge.
UPDATE: Comet Pojmansk is in the observing news! Now rounding the Sun, it will make its nearest approach to Earth on March 5. At the beginning of the week it averages a magnitude approaching 7 and is brightening fast – possibly coming within unaided viewing range within days. By Monday morning it should reach visiblity for the northern hemisphere and reach a maximum elongation of 22 degrees. Check out a map from SkyHound and be on the lookout!!

Monday, February 27 – Today is the birthday of Bernard Lyot. Born in 1897, Lyot went on to become the inventor of the coronagraph in 1930. Although we cannot hand you a corona, we can show you a star that wears its own gaseous envelope.

Let’s go to our maps west of M36 and M38 to identify AE Aurigae. As an unusual variable, AE is normally around 6th magnitude and resides approximately 1600 light years distant. The beauty in this region is not particularly the star itself but the faint nebula in which it resides known as IC 405, an area of mostly dust and very little gas. What makes this view so entertaining is that we are looking at a “runaway” star. It is believed that AE once originated from the M42 region in Orion. Cruising along at a very respectable speed of 80 miles per second, AE flew the “stellar nest” some 2.7 million years ago! Although IC 405 is not directly related to AE, there is evidence within the nebula that areas have been cleared of their dust by the rapid northward motion of the star. AE’s hot, blue illumination and high energy photons fuel what little gas is contained within the region. Its light also reflects off the surrounding dust. Although we cannot “see” with our eyes like a photograph, together the pair forms an outstanding view for the small backyard telescope and it is known as “The Flaming Star.”

Tuesday, February 28 – Are you ready for a New Moon challenge? Then take advantage of dark sky time to head toward Orion. Tonight our aim is toward a single star – but there is much more hiding there than just a point of light!

Our first stop is the eastern-most star in the “belt,” Zeta Orionis, or better known as Alnitak. At a distance of some 1600 light years, this 1.7 magnitude beauty contains many surprises ? it’s a double star system. High power and steady skies are needed to make Alnitak’s duplicity clear, but if you want more, look a breath east and revisit the Flame Nebula – a fantastic field of nebulosity illuminated by Alnitak. The NGC 2024 is an outstanding region of nebulosity spread over an area the apparent size of a full moon.

Still not enough? Break out the big scope and put Zeta out of the field of view to the north at high power and allow your eyes to re-adjust. When you look again, you will see a long, faded ribbon of nebulosity called IC 434 south of Zeta. It stretches over a degree toward the south. The eastern edge of the “ribbon” is very bright and mists away to the west. Now hold your breath and look almost directly in the center. See that dark notch with two faint stars south of it? You have located one of the most famous of the Barnard dark nebulae – B33.

You may exhale now. B33 is also known as the “Horsehead Nebula.” This “Horsehead” is very tough visually – the classic chess piece appearance of a “knight” is only fully appreciated in photographs – but those of you who have large aperture can see a dark “notch,” improved with the use of a specific nebula filter. B33 is a small area cosmically, only about one light year in expanse. It’s nothing more than obscuring dark dust and non-luminous gas – but what an incredible shape! If you do not succeed at first attempt, try again. The “Horsehead” is one of the most challenging objects in the sky and has been observed with apertures as small as 150mm. This just might be your lucky “Knight”?

Wednesday, March 1 – George Abell was born this day in 1927. Abell cataloged 2712 clusters of galaxies based on the Palomar sky survey completed in 1958. Using plates taken by the 48-inch Oschin Schmidt telescope, Abell put forth the idea that the grouping of galaxy clusters related to the overall arrangement of matter in the universe. He developed the “luminosity function” – correlating brightness and number of members in clusters with distance. Abell also discovered a number of planetary nebulae and developed, along with Peter Goldreich, the theory of planetary evolution from red giants.

With the moon out of the picture early, why not get caught up in a galaxy cluster study – Abell 426. Located just 2 degrees east of Algol in Perseus, this group of 233 galaxies spread over a region of several degrees of sky is easy enough to find – but difficult to observe. Spotting Abell galaxies in Perseus can be tough in smaller instruments, but those with large aperture scopes will find it worthy of time and attention.

At magnitude 11.6, NGC 1275 is the brightest of the group and lies physically near the core of the cluster. Glimpsed in scopes as small as 150 mm aperture, NGC 1275 is a strong radio source and an active site of rapid star formation. Images of the galaxy show a strange blend of a perfect spiral being shattered by mottled turbulence. For this reason NGC 1275 is thought to be two galaxies in collision.
Depending on seeing conditions and aperture, galaxy cluster Abell 426 may reveal anywhere from 10 to 24 small galaxies as faint as magnitude 15. The core of the cluster is more than 200 million light-years away, so it’s an achievement to spot even a few!

Thursday, March 2 – Tonight the Moon appears as a very slender crescent setting to the west in Pisces. This lunar apparition looks very much like a pair of bright horns bearing a dark disk. Such a moon may have given rise to the ancient symbol associated with fertility goddesses originating in Egypt and Mesopotamia. Today we see it “as the old moon in the new moon’s arms.” To see this lunar phase is an Astronomical League challenge.

Skies darken early again tonight, so we’ll have a look at an open cluster easily seen in binoculars and well resolved in small scopes. Start at bright Castor and Pollux in Gemini and turn your eyes, binoculars, or finder scope almost due south to even brighter Procyon. Drop almost the same distance to Xi Puppis. Once you locate Xi, shift the scope or binoculars roughly one finger-width (two degrees) northwest. There you will see a hazy rectangular patch with a handful of barely resolvable stars in its midst – the open cluster M93.

First cataloged by Charles Messier in March of 1781, this wonderfully bright grouping contains a broad range of stellar types among its 80 or so members. Even at a distance of 3500 light-years, binoculars reveal the cluster’s bright haze and sharply angular swatch of core stars and a scope will resolve it. Towards the center, a wedge-shaped collection of bright members congregate. At the heart of the wedge is an easy double star – with another echoing the pair to the west. The very brightest of these stars are young, hot, and blue with an overall stellar population similar to the Pleiades. How old you ask? A very young one million years.

Friday, March 3 – With the Moon near the horizon, we have only a short time to view its features. Tonight let’s start with a central feature – Langrenus – and continue further south for crater Vendelinus. Spanning 92 by 100 miles and dropping 14,700 feet below the lunar surface, Vendelinus displays a partially dark floor with a west wall crest catching the brilliant light of an early sunrise. Notice also that its northeast wall is broken by a younger crater – Lame. Head’s up! It’s an Astronomical League challenge.

Once the Moon has set, revisit M46 in Puppis – along with its mysterious planetary nebula NGC 2438. Follow up with a visit to neighboring open cluster M47 – two degrees west-northwest. M47 may actually seem quite familiar to you already. Did you possibly encounter it when originally looking for M46? If so, then it’s also possible that you met up with 6.7 magnitude open cluster NGC 2423, about a degree northeast of M47 and even dimmer 7.9 magnitude NGC 2414 as well. That’s four open clusters and a planetary nebula all within four square arc-minutes of sky. That makes this a cluster of clusters!

Let’s return to study M47. Observers with binoculars or using a finderscope will notice how much brighter, and fewer, the stars of M47 are when compared to M46. This 12 light-year diameter compact cluster is only 1600 light-years away. Even as close as it is, not more than 50 member stars have been identified. M47 has about one tenth the stellar population of larger, denser, and three times more distant, M46.

Of historical interest, M47 was “discovered” three times: first by Giovanni Batista Hodierna in the mid-17th century, then by Charles Messier some 17 years later, and finally by William Herschel 14 years after that. How is it possible that such a bright and well-placed cluster needed “re-discovery?” Hodierna’s book of observations didn’t surface until 1984, and Messier gave the cluster’s declination the wrong sign, making its identification an enigma to later observers – because no such cluster could be found where Messier said it was!

Saturday, March 4 Born on this date in 1835, Giovanni Schiaparelli opened his eyes (and later ours) to a new world of possibilities – life on Mars. As director of Milan Observatory in 1877, Schiaparelli first described fine, faint features on the surface of Mars as “canali.” Perhaps one of Schiaparelli’s most important contributions was making the connection between meteor streams and the comets that produced them.

Tonight let’s return to our studies of the Moon and a more challenging crater. Further south than Vendelinus, look for another large, mountain-walled plain named Furnerius not too far from the terminator. Although it has no central peak, its walls have been broken numerous times by many smaller impacts. Look at a rather large one just north of central on the crater floor. If skies are stable, power up and search for a rima extending from the northern edge. Keep in mind as you observe that our own Earth has been pummeled just as badly as its satellite.

Sunday, March 5 – Today is the 494th anniversary of Gerardus Mercator’s birth in 1512. The famed mapmaker went on to live a life of great moral courage. Mercator’s time was a rough one for astronomy and astronomers. Despite a prison sentence and threats of torture and death for his “beliefs,” Mercator went on to design a globe of the earth in 1541 and one for the heavens ten years later. One sphere within a larger one – and all without the many complexities envisioned by Ptolemy a millennium before him.

Tonight the Moon provides an opportunity to view to a very changeable and eventually bright feature on the lunar surface – Proclus. At 28 km in diameter and 2400 meters deep, crater Proclus will appear on the terminator to the west of Mare Crisium’s mountainous border. Depending on your viewing time, it will seem to be about two-thirds shadowed, but the remainder of the crater will shine brilliantly. Proclus has an unusually high albedo, or surface reflectivity, of about 16%. This is uncommon for most lunar features. Watch this area over the next few nights as two rays from the crater widen and lengthen, extending approximately 320 kilometers north and south.

Now, just look at the Moon. Can you spot the Pleiades nearby?

Now let’s have a go at the dense open cluster NGC 2301. Located about two finger-widths northwest of visual double Delta Monoceros, this 6th magnitude cluster can be seen in binoculars as a small, faint haze divided by a line of barely resolved stars. Telescopes will reveal a half dozen bright stellar members, plus a number of small clumps of dimmer stars.

Keep rockin’ the night and may all your journeys be at light speed! ….~Tammy Plotner with additional writing by Jeff Barbour @ astro.geekjoy.com

Posted on by Fraser Cain

NASA’s Orbiter is Almost at Mars

Artist’s concept of Mars Reconnaissance Orbiter approaching Mars. Image credit: NASA/JPL Click to enlarge
As it nears Mars on March 10, a NASA spacecraft designed to examine the red planet in unprecedented detail from low orbit will point its main thrusters forward, then fire them to slow itself enough for Mars’ gravity to grab it into orbit.

Ground controllers for Mars Reconnaissance Orbiter expect a signal shortly after 1:24 p.m. Pacific time (4:24 p.m. Eastern time) that this mission-critical engine burn has begun. However, the burn will end during a suspenseful half hour with the spacecraft behind Mars and out of radio contact.

“This mission will greatly expand our scientific understanding of Mars, pave the way for our next robotic missions later in this decade, and help us prepare for sending humans to Mars,” said Doug McCuistion, Director of NASA’s Mars Exploration Program. “Not only will Mars Science Laboratory’s landing and research areas be determined by the Mars Reconnaissance Orbiter, but the first boots on Mars will probably get dusty at one of the many potential landing sites this orbiter will inspect all over the planet.”

The orbiter carries six instruments for studying every level of Mars from underground layers to the top of the atmosphere. Among them, the most powerful telescopic camera ever sent to a foreign planet will reveal rocks the size of a small desk. An advanced mineral-mapper will be able to identify water-related deposits in areas as small as a baseball infield. Radar will probe for buried ice and water. A weather camera will monitor the entire planet daily. An infrared sounder will monitor atmospheric temperatures and the movement of water vapor.

The instruments will produce torrents of data. The orbiter can pour data to Earth at about 10 times the rate of any previous Mars mission, using a dish antenna 3 meters (10 feet) in diameter and a transmitter powered by 9.5 square meters (102 square feet) of solar cells. “This spacecraft will return more data than all previous Mars missions combined,” said Jim Graf, project manager for Mars Reconnaissance Orbiter at NASA’s Jet Propulsion Laboratory, Pasadena, Calif.

Scientists will analyze the information to gain a better understanding of changes in Mars’ atmosphere and the processes that have formed and modified the planet’s surface. “We’re especially interested in water, whether it’s ice, liquid or vapor,” said JPL’s Dr. Richard Zurek, project scientist for the orbiter. “Learning more about where the water is today and where it was in the past will also guide future studies about whether Mars has ever supported life.”

A second major job for Mars Reconnaissance Orbiter, in addition to its own investigation of Mars, is to relay information from missions working on the surface of the planet. During its planned five-year prime mission, it will support the Phoenix Mars Scout, which is being built to land on icy soils near the northern polar ice cap in 2008, and the Mars Science Laboratory, an advanced rover under development for launch in 2009.

However, before Mars Reconnaissance Orbiter can begin its main assignments, it will spend half a year adjusting its orbit with an adventurous process called aerobraking. The initial capture by Mars’ gravity on March 10 will put the spacecraft into a very elongated, 35-hour orbit. The planned orbit for science observations is a low-altitude, nearly circular, two-hour loop. To go directly into an orbit like that when arriving at Mars would have required carrying much more fuel for the main thrusters, requiring a larger and more expensive launch vehicle and leaving less payload weight for science instruments. Aerobraking will use hundreds of carefully calculated dips into the upper atmosphere — deep enough to slow the spacecraft by atmospheric drag, but not deep enough to overheat the orbiter.

“Aerobraking is like a high-wire act in open air,” Graf said. “Mars’ atmosphere can swell rapidly, so we need to monitor it closely to keep the orbiter at an altitude that is effective but safe.” Current orbiters at Mars will provide a daily watch of the lower atmosphere, an important example of the cooperative activities between missions at Mars.

Additional information about Mars Reconnaissance Orbiter is available online at:

http://www.nasa.gov/mro

The mission is managed by JPL, a division of the California Institute of Technology, Pasadena, for the NASA Science Mission Directorate, Washington. Lockheed Martin Space Systems, Denver, is the prime contractor for the project and built the spacecraft.

Original Source: NASA News Release

Posted on by Fraser Cain

Swift Sees an Unusual Gamma Ray Burst

The strange cosmic explosion that occured on February 18th. Image credit: SDSS/Swift Click to enlarge
The Swift satellite, whose mission control center is in State College, has detected a cosmic explosion that has sent scientists around the world scrambling to telescopes to document this startling event. Gamma-ray radiation from the source, detected on 18 February and lasting about half an hour, appears to be a precursor to a supernova, which is the death throes of a star much more massive than the Sun. “The observations indicate that this is an incredibly rare glimpse of an initial gamma-ray burst at the beginning of a supernova,” said Peter Brown, a Penn State graduate student and a member of the Swift science team.

Astronomers are using Swift, whose science and flight operations are controlled by Penn State from the Mission Operations Center in State College, to continue to observe the event. Scores of satellites and ground-based telescopes also are now trained on the sight, watching and waiting. Amateur astronomers in the northern hemisphere with a good telescope in dark skies also can view the source.

The explosion has the trappings of a gamma-ray burst, the most distant and powerful type of explosion known. This event, however, was about 25 times closer and 100 times longer than the typical gamma-ray burst. “This burst is totally new and unexpected,” said Neil Gehrels, Swift principal investigator at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “This is the type of unscripted event in our nearby universe that we hoped Swift could catch.”

The explosion, called GRB 060218 after the date it was discovered, originated in a star-forming galaxy about 440 million light-years away toward the constellation Aries. This is the second-closest gamma-ray burst ever detected, if indeed it is a true burst.

Derek Fox, assistant professor of astronomy and astrophysics at Penn State, who is leading the monitoring effort of GRB 060218 on the Hobby-Eberly Telescope, commented, “This is the burst we’ve been waiting eight years for,” referring to the closest-ever gamma-ray burst, which was detected in 1998. “The special capabilities of Swift, which was not operating in 1998, combined with the intense campaign of ground-based telescopes, should help unravel this mystery,” said Fox.

“There are still many unknowns,” said Penn State Professor of Astronomy and Astrophysics John Nousek, the Swift mission operations director at Penn State University in University Park, Pennsylvania. The burst of gamma rays lasted for nearly 2,000 seconds; in contrast, most such bursts last a few milliseconds to tens of seconds. The explosion also was surprisingly dim. “This could be a new kind of burst, or we might be seeing a gamma-ray burst from an entirely different angle,” he said. The standard theory for gamma-ray bursts is that the high-energy light is beamed in our direction. “This off-angle glance–a profile view, perhaps–has given us an entirely new approach to studying star explosions. Had this burst been farther away, we would have missed it,” Nousek explained.

Because the burst was so long, Swift was able to observe the bulk of the explosion with all three of its instruments: the Burst Alert Telescope, which detected the burst; and the X-ray Telescope, and Ultraviolet/Optical Telescope, which provide high-resolution imagery and spectra across a broad range of wavelengths. Penn State lead the development of the X-ray and Ultraviolet/Optical Telescopes.

Scientists will attempt observations with the Hubble Space Telescope and the Chandra X-ray Observatory. Amateur astronomers in dark skies might be able to see the explosion with a 16-inch telescope as it hits 16th-magnitude brightness.

Swift is a NASA mission in partnership with the Italian Space Agency and the Particle Physics and Astronomy Research Council in the United Kingdom; it is managed by NASA Goddard, and Penn State controls its science and flight operations from the Mission Operations Center in University Park, Pennsylvania.

PSU News Release

Posted on by Fraser Cain

Ausonia Mensa Massif on Mars

Perspective view of the Ausonia Mensa massif. Image credit: ESA Click to enlarge
These images, taken by the High Resolution Stereo Camera (HRSC) on board ESA’s Mars Express spacecraft, show the Ausonia Mensa massif on Mars.

The HRSC obtained these images during orbit 506 with a ground resolution of approximately 37.6 metres per pixel. The scenes show the region of Hesperia Planum, containing the massif, at approximately 30.3 South and 97.8 East. North is to the right in these images.

Ausonia Mensa is a large remnant mountain with several impact craters, rising above basaltic sheet layers. The mountain stretches over an area of about 98 kilometres by 48 kilometres and has an elevation of 3700 metres.

A large crater, approximately 7.5 kilometres in diameter and 870 metres deep, has been partially filled with sediment. The northern flank of the crater is broken by a large gully caused by erosion.

Numerous branched channels, also resulting from erosion, run along the edge of top of the plateau toward the plains at the foot of the mountain.

The western flank of the mountain is dominated by a large crater, about six kilometres in diameter, which clearly shows an ejecta blanket and secondary cratering.

Aeolian, or ‘wind-created’, structures are visible about 50 kilometres to south-east of the massif, indicating channeling of atmospheric flow. They are clearly visible because of their different colour.

***image4:left***A heavily eroded, partially filled crater of approximately six kilometres diameter is visible to the north of the massif. The crater is characterised by numerous, smaller and younger craters.

The colour scenes have been derived from the three HRSC-colour channels and the nadir channel.

The perspective views have been calculated from the digital terrain model derived from the stereo channels.

The 3D anaglyph image was calculated from the nadir and one stereo channel.

Original Source: ESA Portal

Posted on by Fraser Cain

Artificial Star Shines in the Southern Sky

First light of the VLT laser guide star. Image credit: ESO Click to enlarge
Scientists celebrate another major milestone at Cerro Paranal in Chile, home of ESO’s Very Large Telescope array. Thanks to their dedicated efforts, they were able to create the first artificial star in the Southern Hemisphere, allowing astronomers to study the Universe in the finest detail. This artificial laser guide star makes it possible to apply adaptive optics systems, that counteract the blurring effect of the atmosphere, almost anywhere in the sky.

On 28 January 2006, at 23:07 local time, a laser beam of several watts was launched from Yepun, the fourth 8.2m Unit Telescope of the Very Large Telescope, producing an artificial star, 90 km up in the atmosphere. Despite this star being about 20 times fainter than the faintest star that can be seen with the unaided eye, it is bright enough for the adaptive optics to measure and correct the atmosphere’s blurring effect. The event was greeted with much enthusiasm and happiness by the people in the control room of one of the most advanced astronomical facilities in the world.

It was the culmination of five years of collaborative work by a team of scientists and engineers from ESO and the Max Planck Institutes for Extraterrestrial Physics in Garching and for Astronomy in Heidelberg, Germany.

After more than one month of integration on site with the invaluable support of the Paranal Observatory staff, the VLT Laser Guide Star Facility saw First Light and propagated into the sky a 50cm wide, vivid, beautifully yellow beam.

“This event tonight marks the beginning of the Laser Guide Star Adaptive Optics era for ESO’s present and future telescopes”, said Domenico Bonaccini Calia, Head of the Laser Guide Star group at ESO and LGSF Project Manager.

Normally, the achievable image sharpness of a ground-based telescope is limited by the effect of atmospheric turbulence. This drawback can be surmounted with adaptive optics, allowing the telescope to produce images that are as sharp as if taken from space. This means that finer details in astronomical objects can be studied, and also that fainter objects can be observed.

In order to work, adaptive optics needs a nearby reference star that has to be relatively bright, thereby limiting the area of the sky that can be surveyed. To overcome this limitation, astronomers use a powerful laser that creates an artificial star, where and when they need it.

The laser beam, shining at a well-defined wavelength, makes the layer of sodium atoms that is present in Earth’s atmosphere at an altitude of 90 kilometres glow. The laser is hosted in a dedicated laboratory under the platform of Yepun. A custom-made fibre carries the high power laser to the launch telescope situated on top of the large Unit Telescope.

An intense and exhilarating twelve days of tests followed the First Light of the Laser Guide Star (LGS), during which the LGS was used to improve the resolution of astronomical images obtained with the two adaptive optics instruments in use on Yepun: the NAOS-CONICA imager and the SINFONI spectrograph.

In the early hours of 9 February, the LGS could be used together with the SINFONI instrument, while in the early morning of 10 February, it was with the NAOS-CONICA system.

“To have succeeded in such a short time is an outstanding feat and is a tribute to all those who have together worked so hard over the last few years,” said Richard Davies, project manager for the laser source development at the Max Planck Institute for Extraterrestrial Physics.

A second phase of commissioning will take place in the spring with the aim of optimizing the operations and refining the performances before the instrument is made available to the astronomers, later this year. The experience gained with this Laser Guide Star is also a key milestone in the design of the next generation of Extremely Large Telescope in the 30 to 60 metre range that is now being studied by ESO together with the European astronomical community.

Original Source: ESO News Release

Posted on by Fraser Cain

Spiral Galaxy Messier 100

SN 2006X in Messier 100. Image credit: ESO Click to enlarge
Possibly similar to what our own Milky Way looks like, Messier 100 is a grand design spiral galaxy that presents an intricate structure, with a bright core and two prominent arms, showing numerous young and hot massive stars as well as extremely hot knots (HII regions). Two smaller arms are also seen starting from the inner part and reaching towards the larger spiral arms.

The galaxy, located 60 million light-years away, is slightly larger than the Milky Way, with a diameter of about 120 000 light-years.

The galaxy was the target of the FORS1 multi-mode instrument on ESO’s Very Large Telescope, following the request of ESO astronomers Dietrich Baade and Ferdinando Patat, who, with their colleagues Lifan Wang (Lawrence Berkeley National Laboratory, US) and Craig Wheeler (University of Texas, Austin, US), performed detailed observations of the newly found supernova SN 2006X.

SN 2006X was independently discovered early February by Japanese amateur astronomer Shoji Suzuki and Italian astronomer Marco Migliardi. Found on 4 February as the 24th supernova of the year, it had a magnitude 17, meaning it was 1000 times fainter than the galaxy. It was soon established that this was another example of a Type-Ia supernova, observed before it reached its maximum brightness. The supernova indeed brightened up by a factor 25 in about two weeks.

Since SN 2006X became so bright and since it is located inside the very much studied Messier 100 galaxy, there is no doubt that a great wealth of information will be collected on this supernova and, possibly, on the system that exploded. As such, SN 2006X may prove an important milestone in the study of Type Ia supernovae. This is particularly important as these objects are used to measure the expansion of the universe because they all have about the same intrinsic luminosity.

This is not the first supernova ever found in Messier 100. Indeed, this is one of the most prolific galaxies as far as supernovae are concerned. Since 1900, four others have been discovered in it: SN 1901B, SN 1914A, SN 1959E, and SN 1979C. Recent observations with ESA’s XMM-Newton space observatory have shown quite surprisingly that SN 1979C is still as bright in X-ray light as it was 25 years ago. In visible light, however, SN 1979C has since then faded by a factor 250. SN 1979C belongs to the class of Type II supernovae and is the result of the explosion of a star that was 18 times more massive than our Sun.

Original Source: ESO News Release

Posted on by Fraser Cain

Solar Flares Altered Mars’ Atmosphere

Solar flare. Image credit: ESA Click to enlarge
Boston University astronomers announced today the first clear evidence that solar flares change the upper atmosphere of Mars. In an article published in the February 24th issue of the journal Science, the researchers describe how X-ray bursts from the Sun in April 2001 recorded by satellites near Earth reached Mars and caused dramatic enhancements to the planet’s ionosphere ??bf? the region of a planet’s atmosphere where the Sun’s ultraviolet and X-rays are absorbed by atoms and molecules. The measurements were made by the Mars Global Surveyor (MGS) spacecraft at the Red Planet as it transmitted signals to NASA’s antenna sites back on Earth.

“On April 15th and 26th of 2001, radio signals from MGS showed that the Martian ionosphere was unusually dense, and this was the clue that some extra production of ions and electrons had occurred,” explained Michael Mendillo, professor of astronomy, who led the BU research team in its Center for Space Physics.

“At Earth, the GOES satellites measure the Sun’s X-rays almost continuously,” said Dr. Paul Withers of BU. “Our search of their large database discovered several cases of flares occurring just minutes before MGS detected enhancements in Mars’ ionosphere.”

The extra electrons produced by the Sun’s X-rays cause subtle changes in how the MGS radio waves travel toward Earth. Therefore, the team wanted to find several unambiguous case study events before announcing their findings.

The Radio Science Experiment on MGS has made observations of Mars’ ionosphere since its arrival there in late 1999. Its radio transmissions are received by NASA and then cast into scientifically meaningful data by Dr. David Hinson at Stanford University who provides open access to researchers worldwide via a Web site. “We needed Dr. Hinson’s expert advice to make sure that some odd changes in the MGS radio signal had not occurred just by chance,” Dr. Withers added.

To confirm that the photons from these flares had sufficient fluxes to actually modify an ionosphere, additional evidence was sought using measurements on Earth. “During this period, the Sun, Earth and Mars were nearly in a straight line and thus the X-rays measured at Earth should have caused enhancements here as well as at Mars,” Mendillo added.

Using several ionospheric radars spread over the globe, operated by scientists at the University of Massachusetts/Lowell, Professor Bodo Reinisch confirmed that the Sun’s X-rays caused equally impressive modifications to Earth’s ionosphere at the precise times required on those days.

“The science yield from this work will be in the new field of Comparative Atmospheres,” Mendillo pointed out. “By that I mean studies of the same process in nature, in this case making an ionosphere on two planets simultaneously, offer insights and constraints to models not always possible when studying that process on a single planet. The fifth member of our team, Professor Henry Rishbeth of the University of Southampton in England, provides the expertise in theory and modeling that will be the focus of our follow-up studies.”

Founded in 1839, Boston University is an internationally recognized institution of higher education and research. With more than 30,000 students, it is the fourth largest independent university in the United States. BU contains 17 colleges and schools along with a number of multi-disciplinary centers and institutes which are central to the school’s research and teaching mission.

Original Source: Boston University

Posted on by Fraser Cain

Van Allen Safe Zone Migrates

The Van Allen Belts pulsing from solar particles. Image credit: NASA/Tom Bridgman. Click to enlarge
A “safe zone” in the radiation belts surrounding Earth moves higher in altitude and latitude during peaks in solar activity, according to new research by a NASA-led team. The safe zone offers reduced radiation intensities to any potential spacecraft that must fly in the radiation belt region.

“This new research brings us closer to understanding how a section of the radiation belt disappears,” said Dr. Shing Fung of NASA’s Goddard Space Flight Center, Greenbelt, Md. Fung is lead author of a paper on this research appearing in the on-line version of Geophysical Research Letters February 22.

The team based its results on measurements of high-speed particles (electrons), which comprise the “Van Allen radiation belt”, from the National Oceanic and Atmospheric Administration’s series of polar-orbiting meteorological spacecraft during 1978 to 1999. As the spacecraft flew in their polar orbits, they detected fewer radiation belt particles at a certain latitude range, indicating safe zone passages by the spacecraft. The researchers compared the data taken during relatively low solar activity periods, called solar minimum, to data from peak solar activity periods, called solar maximum. They noticed a shift in the safe-zone location towards higher latitudes, and therefore altitudes, during solar maximum.

If the radiation belts were visible, they would resemble a pair of donuts around the Earth, one inside the other with the Earth in the “hole” of the innermost donut. The safe zone, called the “slot region”, would appear as a gap between the inner and outer donut. The belts are actually comprised of high-speed electrically charged particles (electrons and atomic nuclei) that are trapped in the Earth’s magnetic field.

The Earth’s magnetic field can be represented by lines of magnetic force emerging from the South Polar region, out into space and back into the North Polar region. Because radiation-belt particles are charged, their motions are guided by the magnetic lines of force. Trapped particles would bounce between the poles while spiraling around the field lines.

Very Low Frequency (VLF) radio waves and background gas (plasma) are also trapped in this region. Just like a prism that can bend a light beam, the plasma can bend the VLF wave propagation paths, causing the waves to flow along the Earth’s magnetic field. VLF waves clear the safe zone by interacting with the radiation belt particles, removing a little of their energy and changing their direction. This lowers the place above the polar regions where the particles bounce (called the mirror point). Eventually, the mirror point becomes so low that it is in the Earth’s atmosphere. When this happens, the trapped particles collide with atmospheric particles and are lost.

According to the team, the safe zone is created in a region where conditions are favorable for the VLF waves to kick the particles. Their research is the first indication that the location of this region can change with the solar activity cycle. The Sun goes through an 11-year cycle of activity, from maximum to minimum, and back again. During solar maximum, increased solar ultraviolet (UV) radiation heats the Earth’s upper atmosphere, the ionosphere, causing it to expand. This increases the density of the plasma trapped in Earth’s magnetic field.

Favorable conditions for the VLF wave-particle interaction depend on the specific combination of plasma density and magnetic field strength. Although plasma density generally decreases with altitude, expansion of the ionosphere during solar maximum makes the plasma denser at the safe zone’s solar-minimum altitude, and forces the favorable plasma density for the safe zone to migrate to a higher altitude. In addition, magnetic field strength also decreases with altitude. To find the favorable magnetic field strength for the safe zone at higher altitudes, one would have to migrate toward the poles (higher latitudes), where the magnetic field lines are more concentrated and thus stronger.

“This discovery helps narrow down the search for the primary wave-particle interaction region that creates the safe zone,” said Fung. “Although no known spacecraft uses the safe zone extensively now, our knowledge could help planning and operations of future missions that want to take advantage of the zone.”

According to the researchers, their discovery was enabled by a new data selection and retrieval tool developed by the team, called the Magnetospheric State Query System. The research was funded by NASA and the National Research Council. The team includes Fung, Dr. Xi Shao (National Research Council, Washington), and Dr. Lun C. Tan (QSS Group, Inc., Lanham, Md.).

Original Source: NASA News Release

Posted on by Fraser Cain

The High Cost of Boots on the Moon

Artist impression of astronauts returning to the Moon. Image credit: NASA. Click to enlarge.
President Bush suggested that this approach would be both ambitious and reasonable:

Achieving these goals requires a long-term commitment. NASA’s current five-year budget is $86 billion. Most of the funding we need for the new endeavors will come from reallocating $11 billion within that budget. We need some new resources, however. I will call upon Congress to increase NASA’s budget by roughly a billion dollars, spread out over the next five years. This increase, along with refocusing of our space agency, is a solid beginning to meet the challenges and the goals we set today. It’s only a beginning. Future funding decisions will be guided by the progress we make in achieving our goals.

NASA’s new administrator, Michael Griffin further noted in a speech in September 2005 that “not one thin dime” would be directed away from NASA science programs.

As reasonable and optimistic as this statement was, reality has caught up with NASA. And science was the victim.

The White House released President Bush’s new NASA budget proposal for 2007 on February 6. Overall, the budget allocates $16.8 billion for NASA; a 3.2% rise over 2006’s budget.

Specifically, the budget proposes:

  • $6.2 billion for the shuttle and space station
  • $5.3 billion for science
  • $4.0 billion for the new exploration systems

While NASA’s overall budget increases 3.2%, science will only go up by 1.5%, and future budget increases are expected to go up just 1.0% a year through 2011. Factored against inflation, this is essentially a budget decrease. New Scientist gives a good breakdown.

NASA Administrator Michael Griffin dropped the hammer on February 8, explaining what impact this new budget would have on the agency, specifically for its various science programs.

  • Funding for Astrobiology will be cut to 50% of its 2005 levels.
  • Europa mission that would search for life under the moon’s icy surface… cancelled.
  • The Terrestrial Planet Finder – an observatory capable of seeing Earth-sized planets around other stars, and even signs of life… cancelled.
  • The Space Interferometry Mission… delayed.
  • Two scout missions to Mars… cancelled.
  • Dawn mission to explore two asteroids… cancelled.

Ouch. The Terrestrial Planet Finder could make one of the most important discoveries in all of human history; that there’s life on other planets. Please, Mike, anything but that.

The response in the space community was immediate, and ferocious. With good reason. So much good science is being chopped away from NASA.

What’s insane about this whole situation is that NASA should even be forced to choose. If I were in Mike Griffin’s shoes, I’d probably make many of the same decisions. What other decision can he make? The President and Congress have essentially said, “keep flying the shuttle to build the International Space Station, put humans back on the Moon, and figure out how to pay for it.” Science is all that’s left to cut from. If the new exploration vehicle goes over budget, science will have to pay for that too.

Flying the shuttle isn’t about rocket fuel, it’s about the standing army of thousands of employees who work across the United States. These people do important, complicated and specialized work on the shuttle, and you can’t just wish them away with a magic wand. NASA exists in the real world, with all the political considerations that go along with it. People work for NASA, and they’re voters, and they can apply pressure back on Congress, who ultimately approves the budget. The shuttle program has momentum, and nobody can make this process turn on a dime.

The human exploration of space is one of the greatest endeavours we can embark on. The whole point of space exploration is to learn how to get humans into space. At some point that requires putting human beings into rocket ships, blasting them into space, and figuring out what it takes to survive outside of the Earth. You have to keep doing that until humans don’t need to come back, and humanity becomes a true spacefaring civilization.

NASA shouldn’t be forced to choose between science and exploration. Why not pick up all of NASA’s science related activities and put them under the umbrella of the National Science Foundation? They’re slated to receive $5.8 billion for FY2007.

I would still be uncomfortable to have to choose between particle accelerators, genetic research and Martian rovers, but it’s probably a much more appropriate choice to have to make.

Written by Fraser Cain