Universe Today

January 23, 2009April 26, 2016 by Nancy Atkinson

Chandrayaan-1 Instrument Detects First X-ray Signature from Moon

Chandrayaan-1 was flying over the nearside of the Moon when the flare went off – in a region of lunar highlands close to the crater Boscovich. Credit: STFC

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The X-ray instrument on board the Chandrayaan-1 spacecraft orbiting the moon was switched on and successfully detected its first X-ray signature from the moon. The C1XS X-ray camera, (pronounced like “kicks”) detected the X-ray signal from a region near the Apollo landing sites on December 12th 2008 at 02:36 UT. The solar flare that caused the X-ray fluorescence was exceedingly weak, approximately 20 times smaller than the minimum C1XS was designed to detect, which is good news for the sensitivity of the instrument. “C1XS has exceeded expectations as to its sensitivity and has proven by its performance that it is the most sensitive X-ray spectrometer of its kind in history,” said Ms. Shyama Narendranath, Instrument Operations Scientist at the Indian Space Research Organisation (ISRO).

The instrument will help map out the composition of the Moon in much greater detail than has ever been done, and could help settle a long-running debate about how the Moon formed.

The leading theory of how the Moon was created is that a Mars-sized object slammed into the Earth early in its history, creating our orbiting moon. A better accounting of the Moon’s makeup is needed to solidify the theory.

A few other spacecraft, like Chandra have taken X-ray images of the moon, but X-ray imaging from Earth is impossible because our atmosphere cuts out X-rays from space.

The C1XS will work by looking at the X-rays from our sun that have been absorbed by atoms in the lunar soil, then re-emitted in such a way as to reveal the chemistry of the surface. The spectrometer is sensitive to magnesium, aluminium and silicon x-rays.

The red curve shows the combined signal from all 24 C1XS X-ray detectors during the solar flare at 02:35-02:38 UT on Dec. 12th. The black dashed line shows the normal background signal detected by C1XS. The three “fingers” sticking up between 1 and 2 keV are due to the presence of the elements magnesium, aluminium and silicon (left to right) on the Moon. Credit: STFC

The X-ray camera collected 3 minutes of data from the Moon just as the flare started and the camera finished its observation. The signal reveals the X-ray fingerprint of a part of the lunar surface. As the mission continues, C1XS will build up a detailed picture of the ingredients that have gone into the Moon.

Barry Kellett, instrument scientist from the UK’s Science and Technologies Facilities Council said, “Despite the small quantity of data, our initial analysis and modeling shows that C1XS has identified the chemistry of this area of the Moon.”

The instrument was jointly developed by the UK’s STFC Rutherford Appleton Laboratory and ISRO.
Professor Richard Holdaway, Director of STFC’s Space Science and Technology Department, said, “We are thrilled that C1XS has started its mission so successfully and is exceeding expectations. This sophisticated instrument will not only help us better understand the origin of the Earth-Moon system but will ensure that the UK plays an important role in this international activity.”

Source: STFC

January 23, 2009December 24, 2015 by Tammy Plotner

Weekend SkyWatcher’s Forecast – January 23-25, 2009

Greetings, fellow SkyWatchers! Are you ready for a dark sky weekend? Then let’s get out the telescope and do some super sleuthing as we investigate some nebulae – both familiar and unfamiliar. While it’s always fun to pick the biggest and brightest out of the sky, there’s lots of wonderful little mysteries to be explored if you just know where to look! It’s all about what you can do and what you can learn – and why being just “a backyard astronomer” can be so very important! I’ll see you out there…

Friday, January 23, 2009 – Tonight travel a finger-width northeast of Zeta Orionis for a delightful area of bright nebulosity called M78 (RA 05 46 47 Dec +00 00 50). Discovered by Mechain in 1789, the 1,600 light-year distant M78 is part of the vast complex of nebulae and star birth comprising the Orion region. Fueled by twin stars, it resembles a ‘‘double comet’’ to binoculars, but telescopic observers will note two lobes ( NGC 2067 north and NGC 2064 south) separated by a band of dark dust. Surrounded by a region of absorption, M78’s borders appear almost starless. Young T Tauri-type stars reflect against a cloud of interstellar dust, the brightest of which is HD 38563A. As of 1999, 17 Herbig-Haro objects (newly forming stars that are expelling jets of matter) have been associated with M78.

On January 23, 2004, a young backyard astronomer named Jay McNeil was taking some long exposure photos of M78 with his new telescope and was about to make a huge discovery. When he developed his photographs, there was a nebulous patch with no designation! After reporting his findings to professionals, Jay realized he had stumbled onto something unique, a variable accretion disk around a newborn star—IRAS 05436-0007. Although McNeil’s Nebula may not be bright enough tonight to be seen (just south of M78), remember it is a variable, so circumstances play a big role in any observation of it.

Before you assume that being ‘‘just’’ a backyard astronomer has no real importance to science, remember this teenager in a Kentucky backyard with an ordinary telescope… catching what professionals had missed!

Saturday, January 24, 2009 – Today honor the 1882 birth of Harold Babcock , discoverer of the sunspot cycle, differential rotation, and the solar magnetic field. While you should NEVER look directly at the Sun, you can use binoculars or telescopes to see sunspots by using the ‘‘projection method’’—just as Gassendi did to observe the Mercury transit. Cover additional optics such as a finderscope or one binocular tube, and use the shadow to aim the circle of light onto a makeshift screen, focusing until the image is sharp and details appear. It takes practice, but it’s safe and fun!

Tonight, journey two finger-widths northwest of Aldebaran (RA 04 21 57 Dec +19 32 07). In 1852, J.R. Hind reported observing nebulosity, but noted no catalog position. His observation included an uncharted star, which he surmised was variable. On each count, Hind was right. The pair was studied for several years until they faded in 1861, and then disappeared altogether in 1868. In 1890, E.E. Barnard and S.W. Burnham re-discovered them, only to see them vanish 5 years later—not to return until the 20th century.

Our mystery guests are Hind’s Variable Nebula ( NGC 1555), and its associated star— T Tauri —a prototype of a particular class of variables and totally unpredictable. For weeks its magnitude could fluctuate between 9 and 13—or remain constant for months. Although equal to Sol in temperature, mass, and spectral chromosphere signature, it is in the initial stages of birth! T Tauri types are pre-main sequence proto-stars, continuously contracting and expanding and shedding their mantle of gas and dust in jets. This is caught by the star’s rotation and spun into an accretion, or proto-planetary, disk. When the jets subside, gravity pulls the material back to the star. The proto-star has then cooled enough to reach the main sequence, and the pressure may even allow planetoids to form from the accreted material.

How cool is that?!

Sunday, January 25, 2009 – On this date we celebrate the 1736 birth of Joseph Lagrange, a mathematician who made a very important contribution to celestial mechanics. No, we aren’t talking about wrenches in space! He calculated five locations where the combined gravity of Earth and the Sun would balance the orbital motion of an object positioned there. A spacecraft located at one of these spots—the one about a hundredth of the distance from Earth to the Sun—requires little correction to maintain orbit and keep pace with Earth’s rotation. Known as the Lagrange Point 1, it’s a position currently occupied by the most prolific solar ‘‘observer’’ to date… the SOHO satellite!

How often do we look at something and not see what is really there simply because we don’t know what to look for? Tonight, look north of Aldebaran for a small cluster of stars, and focus your attention toward the northernmost star, Nu Tauri. Surrounding this rather ordinary star is an overlooked nebula—Ce 34.

In 1964, an industrious astronomer—Stefan Cederblad—began studying bright, diffuse galactic nebulae and their distribution. Chances are you may have seen a Cederblad catalog object at one time or another and not even have noticed it! In this circumstance, Ce 34 is illuminated by 72 Tauri, which looks like an apparent double for Nu. At first glance, you might think you were seeing diffraction or illumination from the Nu/72 pair, but Stefan was a true astronomer and repeated his observation until he was sure he had discovered nebulosity.

Take time to study Ce 34 yourself. You might find catching it depends not so much on the size of your optics but rather you and your observing conditions! Just like the Merope Nebula , the art is not so much in the finding as it is in the seeing.

Until next week, remember… Dreams really do come true when you keep on reaching for the stars!

This week’s awesome images are: M78 (credit—Palomar Observatory, courtesy of Caltech), ’’McNeil’s Nebula’’ (credit—Adam Block/NOAO/AURA/NSF), NGC 1555: Hind’s Variable Nebula (credit—Palomar Observatory, courtesy of Caltech), Harold Babcock (historical image), Lagrange points (credit—NASA) and Cederblad 34 (credit—Palomar Observatory, courtesy of Caltech). We thank you so much!

January 22, 2009December 24, 2015 by Nancy Atkinson

More Top Secret in Space: Inspecting a Crippled Defense Satellite

An artist's concept shows a DSP satellite deployed in space. Credit: Northrop Grumman

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Two small, covert inspection satellites capable of maneuvering around in geosynchronous orbit are being used by the U.S. Defense Department to inspect a $400 million missile warning satellite that failed in 2008. This is the first time this type of operation has been done, demonstrating a new ability by the U.S. military. “There is not much we do in space any more that is really new, but this is really new,” said John Pike, who heads the military think tank GlobalSecurity.Org, in an article by Craig Covault in Spaceflightnow.com. Pike went on to say that although this operation is being used to obtain data on a failed U.S. spacecraft, such inspections of especially potential enemy spacecraft, is something the Pentagon has wanted to do since the start of the space age. And what implications would this type of spacecraft have for NASA’s ability to monitor and repair satellites and orbiting spacecraft in the future?

The U.S. Air Force/Northrop Grumman Defense Support Program DSP 23 missile warning satellite was launched successfully in 2007, but failed shortly after in 2008. It was the first launch of the Delta 4-Heavy booster, which was recently used again to launch a military satellite on January 17, 2009.

The satellites are about 40,230 km (25,000 miles) above the Earth. The Orbital Sciences and Lockheed Martin “Mitex” inspection spacecraft are part of a classified Defense Advanced Research Projects Agency (DARPA) technology development program. When they were launched in 2006, the project involved maneuvering around and inspecting each other in geosynchronous orbit. But no data is available to indicate whether the two spacecraft may have secretly paid visits to one or more non-U.S. spacecraft in the geosynchronous: everything about these spacecraft is classified.

The Mittex spacecraft and the Delta 2 rocket. Credit: Spaceflightnow.com

The small Mitex spacecraft are unusually small — only about 500 pounds each. Most all geosynchronous satellites are much larger. Officials from Union of Concerned Scientist’s Global Security Program. Said that the Chinese will complain about the operations to the international community in Geneva, Switzerland, as they are concerned about the implications of these satellites’ capabilities, but also about how the U.S. is always complaining about the need for transparency in Chinese space operations, but now the U.S. is conducting secret operations.

While the military aspects of the Mitex spacecraft are unique, it also provides fuel for thought about what these type of spacecraft could mean for NASA and commercial satellite companies for surveillance and possible repair of satellites and orbiting spacecraft.

For more information about the military implications of this surveillance spacecraft see the article on Spaceflightnow.com.

January 22, 2009December 24, 2015 by Tammy Plotner

Triangulum

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Triangulum, located just north of the ecliptic plane, was one of the 48 original constellations listed by Ptolemy, and remains one of the 88 modern constellations. It spans 132 square degrees of sky and ranks 78th in size. Triangulum has 3 mains stars in its asterism and 15 Bayer Flamsteed designated stars within its confines. It is bordered by the constellations of Andromeda, Pisces, Aries and Perseus. Triangulum can be seen by all observers located at latitudes between +90° and ?60° and is best seen at culmination during the month of December.

As one of the very few constellations to be named after an object instead of a mythical figure or animal, one of the first names of this constellation was Sicilia – which represented the island of Sicily. This tale came about because it was believed that Ceres, the patron goddess, had begged Jupiter to immortalize her home in the stars. For a time, this region of sky was also known as Triangulum Minus, as recorded by Johannes Hevelius. It was formed from the southern parts of his Triangula, and the name quickly fell into disuse. It eventually simply took on the Latin term for its three primary stars the “triangle” and has been referred to as Triangulum ever since.

Let’s begin our binocular tour of Triangulum with its brightest star – Beta – the “B” symbol on our chart. Beta often goes by the name Deltotum, which is a Greek letter – Delta – which also resembles a triangle. Beta is a white A-type giant star located about 124 light years from Earth. Now switch off to the second brightest star – Alpha – the “a”. Its name is Mothallah – the head of the triangle. Guess what? It’s a binary star! While you won’t be splitting this spectroscopic yellow-white F-type subgiant binary star with any optics, it’s still fun to know that its diameter is about 3 times as large as the Sun and that its companion orbits it in less than 2 days from a distance of under 4 million miles. That’s almost touching in astronomical terms! By the way… They’re both about 65 light years away from our solar system. For a binary star you can separate in a telescope, have a look at 6 Trianguli. Its 5.3 and 6.9 components are easy to pick apart even with a small telescope because they are separated by almost 40 arc seconds.

Now, you might need to get out your telescope for the next object… A long term variable star named R Trianguli (RA 02: 34 DEC +34: 03). Depending on when you start, you may have a long time to wait to see changes, because R takes 266 days to go from stellar magnitude 5.7 to an almost invisible 12.4! R Trianguli is an “M-class” Red giant star who owes its changes to pulsations. As it expands, it becomes brighter… As it contracts, it becomes faint. What an incredible star to watch!

For binoculars and rich field telescopes, it’s time to head towards the ghostly galaxy, Messier 33 (RA 1 : 33.9 Dec +30 : 39). While this incredible spiral galaxy has an apparent magnitude of 5.7, you’re not going to find it quite as easy to find as you might think. Why? Because a lot of times you’re going to be missing the forest because you’re looking at the trees. M33 is huge! Located some approximately 3 million light-years away, the “Pinwheel Galaxy” contains a host of its own NGC objects and can often be spotted without optical aid from a dark sky location. One of the most positive ways to locate it is to use the very lowest magnification eyepiece you have available and work your way up to study each portion. It is the third largest galaxy in the Local Group, a group of galaxies that also contains the Milky Way Galaxy and the Andromeda Galaxy, and it may be a gravitationally bound companion of the Andromeda Galaxy.

The Triangulum Galaxy was probably discovered by Giovanni Batista Hodierna before 1654, who may have grouped it together with open cluster NGC 752. It was independently discovered by Charles Messier in 1764, who catalogued it as M33 on August 25. M33 was also catalogued independently by William Herschel on September 11, 1784 number H V.17. It was among the first “spiral nebulae” identified as such by Lord Rosse. Herschel also cataloged The Triangulum Galaxy’s brightest and largest H II region (diffuse emission nebula containing ionized hydrogen) as H III.150 separately from the galaxy itself, which eventually obtained NGC number 604. As seen from Earth NGC 604 is located northeast of the galaxy’s central core, and is one of the largest H II regions known with a diameter of nearly 1500 light-years and a spectrum similar to the Orion Nebula. Herschel also noted 3 other smaller H II regions (NGC 588, 592 and 595).

In 2005, using observations of two water masers on opposite sides of Triangulum via the VLBA, researchers were, for the first time, able to estimate the angular rotation and proper motion of Triangulum. A velocity of 190 to 60 km/s relative to the Milky Way is computed which means Triangulum is moving towards Andromeda. In 2007, a black hole about 15.7 times the mass of the Sun was detected in the galaxy using data from the Chandra X-ray Observatory. The black hole, named M33 X-7, orbits a companion star which it eclipses every 3.5 days. Although we can never see it, we can certainly enjoy this faint galaxy for all the mysteries it holds!

Keep your telescope handy as you head off for our next galactic designation, NGC 925 (RA 2 : 27.3 Dec +33 : 35). At magnitude 10 and nearly 10 arc minutes in size, it is also fairly easy for a small telescope and large binoculars. This face-on presentation spiral galaxy is also part of the Hubble Space Telescope project for extra-galactic distances which use Cepheid variable stars to help judge that vast expanse of space between us. Look for a bright core region with elongated wispy spiral galaxy structure!

Now try your hand, and your telescope, and NGC 672 (RA 1 : 47.9 Dec +27 : 26). At close to magnitude 11 and 7 arc minutes in size, it is a bit more of a challenge, but large telescopes will find it and interacting galaxy IC 1727 in the same field of view. The pair is believed to be separated by about 88,000 light years – or about their own diameters. While you won’t catch an outstanding amount of detail in either one, you may begin to resolve out some lumpy areas of star birth!

Last, but not least, is NGC 784 (RA 2 : 01.3 Dec +28 : 50). At magnitude 12 and about 6 arc minutes in size, it is the smallest and faintest challenge yet. It is a barred-spiral galaxy presented nearly edge-on, and it is very diffuse. In spite of its expected small distance, NGC 784 has not yet been resolved into stars and is still being studied for velocity and kinematics. Good luck!

Sources:
SEDS
Wikipedia
Chart courtesy of Your Sky.

January 22, 2009May 5, 2017 by Fraser Cain

What is the Atmosphere Like on Saturn?

Natural color images taken by NASA's Cassini wide-angle camera, showing the changing appearance of Saturn's north polar region between 2012 and 2016.. Credit: NASA/JPL-Caltech/Space Science Institute/Hampton University

Like the rest of the planet, the atmosphere of Saturn is made up approximately 75% hydrogen and 25% helium, with trace amounts of other substances like water ice and methane.

From a distance, in visible light, Saturn’s atmosphere looks more boring than Jupiter; Saturn has cloud bands in its atmosphere, but they’re pale orange and faded. This orange color is because Saturn has more sulfur in its atmosphere. In addition to the sulfur in Saturn’s upper atmosphere, there are also quantities of nitrogen and oxygen. These atoms mix together into complex molecules we have here on Earth; you might know it as “smog”. Under different wavelengths of light, like the color-enhanced images returned by NASA’s Cassini spacecraft, Saturn’s atmosphere looks much more spectacular.

Saturn has some of the fastest winds in the Solar System. As NASA’s Voyager spacecraft was approaching Saturn, it clocked winds going as fast as 1800 km/hour at the planet’s equator. Large white storms can form within the bands that circle the planet, but unlike Jupiter, these storms only last a few months and are absorbed into the atmosphere again.

The part of Saturn that was can see is the visible cloud deck. The clouds are made of ammonia, and sit about 100 km below the top of Saturn’s troposphere (the tropopause), where temperatures dip down to -250 degrees C. Below this upper cloud deck is a lower cloud deck made of ammonium hydrosulphide clouds, located about 170 km below. Here the temperature is only -70 degrees C. The lowest cloud deck is made of water clouds, and located about 130 km below the tropopause. Temperatures here are 0 degrees; the freezing point of water.

Below the cloud decks pressures and temperatures increase with depth, and the hydrogen gas slowly changes to liquid. And below that, the helium forms a liquid as well.

We have written many articles about Saturn for Universe Today. Here’s an article about long-term patterns in Saturn’s atmosphere, and here’s an article about Saturn’s southern atmosphere.

Want more information on Saturn? Here’s a link to Hubblesite’s News Releases about Saturn, and here’s NASA’s Solar System Exploration Guide.

We have recorded a podcast just about Saturn for Astronomy Cast. Click here and listen to Episode 59: Saturn.

References:
NASA APOD
NASA Saturn Fun Facts

January 22, 2009December 24, 2015 by Nancy Atkinson

Has the Moon Changed Its Face?

The far side of the moon, as seen by the Apollo 16 astronauts. Credit: NASA

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The moon’s “near side” always faces Earth, because the moon spins once on its axis in precisely the same amount of time it takes to revolve around the Earth. But things could have been different billions of years ago. A computer analysis of the amount of craters on the different hemispheres of the Moon shows that the far side may have once been facing Earth. A large asteroid impact may have caused the moon to change the way its faces Earth.

One consequence of the Moon being locked in a spin-orbit resonance of synchronous rotation is that more impacts should occur on the Moon’s western hemisphere than the eastern, as that side would be facing into orbit, making it more likely to be hit by debris.

But Mark Wieczorek and Matthieu Le Feuvre at the Paris Institute of Earth Physics in France compared the relative ages of the craters, using data about the sequence in which ejected material was deposited on the surface, and they found the opposite to be true. Although the youngest impact basins were concentrated in the western hemisphere, as expected, the older craters were mostly congregated in the east. This suggests that the eastern face had once been bombarded more than the western face.

This could have happened if a large asteroid impact caused the moon to do an about face. The researchers estimate after the impact, the moon would have appeared to turn slowly as viewed from Earth, and slowly would have come into its current position.

In looking at several of the largest lunar impact basins, there are several suspects for impacts that could have temporarily unlocked the Moon from synchronous rotation.

“We show that there is less than a 2% probability that the oldest lunar impact basins are randomly distributed across the lunar surface,” the researchers say. “Furthermore, these basins are preferentially located near the Moon’s antapex of motion, and this configuration has less than a 0.3% probability of occurring by chance.”

The team studied the relative age and distribution of 46 known craters. Wieczorek says the Chandrayaan-1 or Kaguya orbiters could provide information on more craters that would help in further research in this area.

For more information, see the abstract.

Sources: New Scientist

January 22, 2009December 24, 2015 by Nancy Atkinson

Scientists Want to Exhume Galileo’s Body

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This is not tops on my list as a good way to celebrate the International Year of Astronomy. Italian and British scientists want to exhume the body of 16th century astronomer Galileo Galilei in order to determine if his severe vision problems may have affected some of his findings. The scientists said DNA tests would help answer some unresolved questions about the health of the man known as the father of astronomy, whom the Vatican condemned for teaching that the Earth revolves around the sun. “If we knew exactly what was wrong with his eyes we could use computer models to recreate what he saw in his telescope,” said Paolo Galluzzi, director of the Museum of History and Science in Florence, the city where Galileo is buried.

Galileo, who lived from 1564 to 1642, was known to have problems with his eyes during his later years, and was totally blind for the last two years of his life. It has long been speculated that he damaged his eyes by looking at the sun through a telescope. But, now some scientists suspect Galileo may have had a form of glaucoma.

“There were periods when he saw very well and periods when he did not see very well,” said Dr. Peter Watson, president of the Academia Ophthalmologica Internationalis and consultant to Addenbrooke’s University Hospital, Cambridge.

One of the “errors” that Galileo made, which Galluzzi suspects may have been because of bad eyesight, is that he thought Saturn’s rings were “handles” or large moons on either side of the planet. Galileo wrote, “I have observed the highest planet [Saturn] to be tripled-bodied. This is to say that to my very great amazement Saturn was seen to me to be not a single star, but three together, which almost touch each other”.

With a 20-power telescope and his eyes in bad shape he might have mistaken Saturn’s rings as two moons on each side.

Or would anyone who had never seen rings around a planet before, using a first-generation telescope think the same?

If the nature of Galileo’s illness was known, Galluzzi said a mathematical model could be simulated to show what Galileo saw through his telescope. “We only have sketches of what he saw. If we were able to see what he saw that would be extraordinary,” Galluzzi said.

Galluzzi added he is waiting for permission from Florence’s Santa Croce Basilica, where Galileo is buried, to exhume the body and then would form a committee of historians, scientists and doctors to oversee the project.

What do you think? Should Galileo be exhumed in the name of science, or should the Father of Astronomy be allowed to rest in peace?

Source: Reuters

January 22, 2009December 24, 2015 by Tammy Plotner

A Twist on the “Trunk” – IC1396 and Van den Berg 142 by Takayuki Yoshida

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Out in the reaches of the constellation of Cepheus some 2400 light years from Earth, a cloud of hydrogen gas and dust harbors young star cluster IC 1396. These newborn stars emit their light upon the scene… shedding infrared radiation through a 20 light year wide corridor known as the “Elephant’s Trunk”…

Cataloged by Dreyer as far back as 1888, galactic cluster IC 1396 has long been known to have an air of nebulosity around it and perhaps a shroud of mystery as well. As telescopes improved, so did the view and observers began to notice dark patches and a bright, sinuous rim. The dark interstellar clouds took a very special observer in the late 1800s to discover them – E.E. Barnard – and he labeled his discovery B163. Nothing more than a cold area in space – obscuring dust waiting to gel into stars. Just another dark hole obscuring a mystery inside IC 1396… and tiny patch of nebula that would one day be known as Van den Berg 142.

In 1975 Robert B. Loren (et al) was the first to report on the molecular cloud structure in IC 1396. His observations were made using the Kitt Peak scope, doing their best to confirm the hypothesis that cometary like structure was the result of an ionization front as it progressed into neutral hydrogen territory. High density gases, a dark rimmed nebula… But, they still didn’t quite grasp what lay inside – a concentration of interstellar gas and dust that is being illuminated and ionized by a very bright, massive star.

And the tiny dense globules hiding from the intense ultraviolet rays…

In 1996, G. H. Moriarty Schieven was the first to announce H I “Tails” from cometary globules in IC 1396. In his reports he writes: “IC 1396 is a relatively nearby, large, H ii region ionized by a single O6.5 V star and containing bright rimmed cometary globules. We have made the first arcminute resolution images of atomic hydrogen toward IC 1396, and have found remarkable “tail” like structures associated with some of the globules and extending up to 6.5 pc radially away from the central ionizing star. These H i “tails” may be material which has been ablated from the globule through ionization and/or photodissociation and then accelerated away from the globule by the stellar wind, but which has since drifted into the “shadow” of the globules.” This report was the first results of the Galactic Plane Survey Project began by the Dominion Radio Astrophysical Observatory and opened the gateway into the twisted tale of the “Trunk”.

The Elephant’s Trunk nebula is an intense concentration of interstellar gas which contains embedded globule IC 1396A and is now believed to be the site of star formation. Located inside the opening where the stellar winds have cleared a cavity are two very young stars – their pressure driving the material outwards and revealing the presence of protostars.

In 2003, Alaina Henry picked up the ball once again. “Since emission line stars are
relatively rare, the discovery of a cluster of emission line stars is adequate proof that star formation is taking place in a cluster. In addition, young stars often display variable luminosity. It is thought that non-constant mass accretion rates cause variations in the luminosity of young stellar objects. BRC 37 is a small globule in the extended, HII region, IC 1396. It is about I’ wide and 5′ long in the optical, and has a bright rim of Ho emission in the north, due to recombination of ionized hydrogen. The source of the ionization is thought to be the 06 star, HO 206267, which lies several degrees away on the sky. The infrared source, IRAS 21388+5622 is located at the head of the globule and showed another signature of star formation in BRC 37 by discovering a bipolar molecular outflow associated with the IRAS source. We identify eight likely young stellar objects in BRC 37, based on the presence of an infrared excess. We also identify four of our observed sources with Ho emission line stars. Of these 11 sources, five are sub-stellar objects, below the hydrogen burning limit. While the eleven objects in table 1 are apparently young stellar objects, it is likely that there are many more young stellar objects in BRC 37… ”

As recently as mid-2005 even more discovery was made by Astrofisico di Arcetri at the end of a 16 year study. “In spite of the relatively high far-infrared luminosities of the embedded sources H2O maser emission was detected towards three globules only. Since the occurrence of water masers is higher towards bright IRAS sources, the lack of frequent H2O maser emission is somewhat surprising if the suggestion of induced intermediate- and high-mass star formation within these globules is correct. The maser properties of two BRCs are characteristic of exciting sources of low-mass, while the last one (BRC 38) is consistent with an intermediate-mass object.”

Around 18 months later at the beginning of 2007, Konstantin V. Getman (et al) used the Chandra X-Ray Observatory to draw conclusions on this same strange area as well: “The IC 1396N cometary globule (CG) within the large nearby H II region IC 1396 has been observed with the ACIS detector on board the Chandra X-Ray Observatory. We detect 117 X-ray sources, of which ~50-60 are likely members of the young open cluster Trumpler 37 dispersed throughout the H II region, and 25 are associated with young stars formed within the globule…. We find that the Chandra source associated with the luminous Class 0/I protostar IRAS 21391+5802 is one of the youngest stars ever detected in the X-ray band.”

Is there even more things yet to be discovered inside the twisted “Trunk”? Astronomers haven’t stopped looking. Just as recently as November 2008 yet another study was released Zoltan Bolag (et al) searching for protoplanetary discs. “Overall, our observations support theoretical predictions in which photoevaporation removes the gas relatively quickly (<=105 yr) from the outer region of a protoplanetary disk, but leaves an inner, more robust, and possibly gas-rich disk component of radius 5-10 AU. With the gas gone, larger solid bodies in the outer disk can experience a high rate of collisions and produce elevated amounts of dust. This dust is being stripped from the system by the photon pressure of the O star to form a gas-free dusty tail." What will the future hold? My many thanks to Takayuki Yoshida of Northern Galactic for turning me on to this incredible image which sparked my desire to learn and share what I’d learned about this region. Arigato!

January 22, 2009December 24, 2015 by Tammy Plotner

Telescopium

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The small constellation of Telescopium is located just south of the ecliptic plane and was originally charted by Abbe Nicolas Louis de Lacaille who named it. It was later adopted by the IAU as one of the modern 88 constellations. Telescopium spans 252 square degrees of sky – ranking 57th in size. It has 2 primary stars in its asterism and 13 Bayer Flamsteed designated stars within its confines. Telescopium is bordered by the constellations of Ara, Corona Australis, Indus, Microscopium, Pavo and Sagittarius. It is visible to observers located at latitudes between +40° and -90° and its primary stars are best seen at culmination during the month of August.

Since Telescopium is considered a “new” constellation, there is no mythology associated with it – only Abbe Nicolas Louis de Lacaille’s love of all things science and what Telescopium is meant to represent – the telescope of Sir William Herschel. In Lacaille’s time, it was called “Beta Telescopii” and when represented on Johann Bode’s charts, it pointed northwards, towards Sagittarius and Corona Australis. Since Bode actually depicted it clear up into Ophichus, he also changed the name to “Tubus Astronomicus” as well. Later, both the name – and the constellation – became more abbreviated as it was adopted by the International Astronomical Union.

Let’s begin our binocular tour of Telescopium with its brightest star – Alpha – the “a” symbol on our chart. While Alpha is far from bright to our vision, this class B (B3) blue subgiant star shines more than 900 times brighter than our own Sun from a distance of 250 light years away. It is a young star, just beginning to evolve away from a core-hydrogen-fusing dwarf. While it is rotating very slowing, Alpha is also chemically peculiar, because it is a helium rich star with very strong stellar magnetic fields. It is believed that it may someday evolve into a massive white dwarf like Sirius-B.

Now aim your binoculars towards Delta – the “8” symbol. It won’t take long to discover this designation is shared by two stars! That’s right, we’re looking at an optical double star. Delta 1 and Delta 2 are both blue-white B-type subgiant stars, but Delta 1 (slightly brighter) is approximately 800 light years from Earth, while Delta 2 is closer to 1,100 light years distant!

Are you ready for Kappa? That’s the “k” symbol on our chart. Kappa Telescopii is also a visual double star. It is a yellow G-type giant star located 293 light years from our solar system.

Get out large binoculars or a small telescope for a look at a very rare type of variable star – RR Telescopii (RA 20 04 18.54 Dec -55 43 33.2). Here we have an example of what is called a Symbiotic Nova. According to the work of F.L. Crawford: “The optical spectrum of RR Tel is very rich in emission. By comparing the results of this study with previous publications on the subject, it is found that the RR Tel system is advancing towards higher degrees of excitation. It is also shown that several nebular lines (for example, [OIII] 4363 Angstroms and NeIV 4714 Angstroms) demonstrate component structure, perhaps caused by the different densities of the emitting plasmas.” Also, infrared and optical photometric and spectroscopic observations of the symbiotic nova RR Telecopii are used to study the effects and properties of dust in symbiotic binaries containing a cool Mira component, as well as showing “obscuration events” of increased absorption, which are typical for such Mira-type variable stars. RR Telescopii erupted in 1944 and took nearly 1600 days to reach maximum. At its lowest, RR can be as dim as magnitude 11 – or as bright as magnitude 7!

Keep a telescope handy to have a look at globular cluster NGC 6584 (RA 18 : 18.6 Dec -52 : 13). At around magnitude 9, this 8 arc minute sized globular will delight you. Discovered by James Dunlop on June 5, 1826 and cataloged originally as Dunlop 376, you will pull a lot of nice resolution out of the core region with larger aperture. A lot of photometry work has been done on this particular star cluster – looking for calcium abundances, blue straggler stars and hot stars located in the galactic halo region.

Now aim your large telescope towards challenging planetary nebula IC 4699 (RA 18 : 18.5 Dec -45 : 59) At magnitude 12 and nearly stellar in size, this particular planetary nebula will be difficult to distinguish from the field without the aid of a nebula filter which will aid in revealing the small disc.

Sources:
SEDS
Wikipedia
Chart Courtesy of Your Sky.

January 22, 2009April 26, 2016 by Ian O'Neill

Top Secret: What Did That Delta IV Heavy Take into Space?

The Delta IV Heavy launch on January 17th (Chris Miller/Spaceflight Now)

[/caption]On Saturday, very little was known about the mammoth payload a Delta IV Heavy was carrying into space. Launching from Florida’s Cape Canaveral Air Force Station, the 70 metre-high rocket blasted into the atmosphere with a mystery satellite known only as the NROL-26 mission. As the acronym suggests, the mission was carrying a National Reconnaissance Office satellite. However, a little after T+7 minutes 40 seconds, shortly after the second stage engines had fired, a media blackout prevented the world from knowing where the payload was going.

Four days on from this secretive rocket launch, what do we know about NROL-26?

The Delta IV Heavy is part of Boeing’s Integrated Defense Systems division Delta IV rocket family. This monster of a launch vehicle can deliver 1.9 million pounds of thrust, carrying large payloads to geosynchronous orbit, some 22,300 miles (36,000 km) above the Earth’s surface. The Delta IV was designed with military and commercial payloads in mind.

Watching the video of Saturday’s launch, one cant help but be in awe of this rocket system. The Delta IV Heavy carried out its second fully successful flight on that day (the Delta IV Heavy first demonstration flight failed to reach the correct orbit in 2004), placing the most expensive (and most clandestine) military spacecraft into orbit. Naturally, details are rather sketchy about what the spacecraft actually is and what it is going to do, but some estimates put the total cost of the rocket plus payload at over $2 billion, so it is obviously a very important mission.

Once NROL-26 successfully reached its destination (wherever that may be), the satellite was renamed “USA 202”. We can say with some certainty that USA 202 is an advanced spy satellite of some description. According to one source, the intent of USA 202 is to act as the next generation in orbital eavesdropping technology, deploying an antenna possibly as wide as 350 feet.

According to GlobalSecurity.org (a military think-tank), USA 202 could be of an “Advanced Mentor” design. Older versions are believed to have been launched by the National Reconnaissance Office and the Central Intelligence Agency under the code name “MENTOR” from 1995 to 2003. These satellites, in geostationary orbits, collect ground-based radio emissions using very large antennae (some as wide as 100 metres). They are also thought to be very big satellites, weighing in at over five tonnes. Like USA 202, these older satellites are highly classified and there is no official word confirming or denying any of the specifications.

Last weekend’s successful Delta IV Heavy launch will come as a relief to the security services operating the top secret satellite as launches have fallen behind schedule through failures and technical challenges. These spy satellites are critical to the White House and Pentagon, as the information gathered by USA 202 aid military decisions and shape foreign policy. In this case, it is thought Saturday’s Delta IV Heavy launch will enhance the ability to intercept communications from rogue states and terrorist organizations around the planet.

Let’s hope USA 202 remains operational for its designated lifespan, as we know what happens to spy satellites that don’t behave…

Sources: Space Flight Now, Space.com, Boeing, Florida Everyone Forgot,