Messier 31: The Andromeda Galaxy

Next to our own Milky Way galaxy, Andromeda is the most well-known galaxy in our universe. At the distance of 2.5 million light-years away, it is the most distant thing we can see with our naked eye. A spiral galaxy, approximately 260,000 light-years across, is the largest of our local group of galaxies, which includes our own Milky Way spanning 100,000 light-years across. On a clear and dark winter night, M31 can be seen as a fuzzy patch of light. It’s an inviting target for binoculars or a telescope. We are best able to see it starting in the fall when it’s high enough in the sky to be seen from nightfall until daybreak. In late September and early October Andromeda shines in the eastern sky at nightfall and stands high in the west at the onset of dawn. Winter evenings are also good for viewing.

How do we find the Andromeda galaxy? The easier way I have found is to use the constellation Cassiopeia, the Queen. It’s easy to recognize because it is in the shape of a “W.” I generally look northward on the sky’s dome to find this constellation. By finding Polaris (the North Star) and by finding the Big Dipper nearby, I can easily see that the Big Dipper and Cassiopeia move around Polaris like hands on a clock. In Cassiopeia, the star “Schedar” points right to Andromeda. Schedar is the second bottom star in the “W.”

When Andromeda was first photographed in 1900 it was thought to be a cloud of gas within our Milky Way and called the Andromeda Nebula. It wasn’t until the 1920’s that Edwin Hubble determined that Andromeda was outside the Milky Way, that it was an individual galaxy, and that these points of light were indeed stars. It wasn’t until 2006 that the Spitzer Space Telescope revealed that Andromeda contained one trillion stars. That’s over twice the amount of stars in the Milky Way, which is estimated to be 200-400 billion.

So what have we learned since 964 when a Persian astronomer found Andromeda and described it as a “small cloud?”  Well, new stars, as well as old stars, could be found there with a dense concentration toward the center. It has a double nucleus, which I interpret as a double “massive black hole,” at the center. As a matter of fact, 26 black holes have been found in the galaxy to date, but not all are massive. There are 450 globular clusters orbiting in and around Andromeda. More recently the KELT North Telescope has detected two large planets in this galaxy: KELT-1b and KELT-1ab. An ancient companion galaxy was ripped up and consumed by Andromeda; the clouds are the remains of the stars of this prior galaxy. There are 14 dwarf galaxies nearby that it regularly bullies. Andromeda is blue-shifted, which means that it and the Milky Way galaxies are on a collision course. But we needn’t worry; this won’t happen for another 4 billion years.  

Images and more information:  http://wise.ssl.berkeley.edu/gallery_andromeda.html

References: EarthSky.org, NASA.org, Space.com, HubbleSite, AstronomyNow.com, CalTech, WISE.ssi.berkley.edu, and Wikipedia.org.  

Jean E. Lane's Imagine This: ALMA: InSearch of Cosmic Knowledge ALMA, short fo...

Jean E. Lane's Imagine This: ALMA: InSearch of Cosmic Knowledge 
ALMA, short fo...: ALMA: In Search of Cosmic Knowledge   ALMA, short for “Atacama Large Millimeter Array,” is the largest observatory ever built. The ob...

ALMA: In Search of Cosmic Knowledge 

ALMA, short for “Atacama Large Millimeter Array,” is the largest observatory ever built. The observatory is located at an altitude of 3.1 miles high on the Chajnantor plateau in the Chilean desert near San Pedro De Atacama, in a place so dry and red it appears that it could be Mars. Dozens of antennas stare at the sky in unison. There is an array of 66 radio telescopes with a diameter of 39 feet and 23 feet observing the sky at millimeter and sub-millimeter wavelengths. They can see deeper and farther in this light than any telescope before. ALMA’s purpose is to provide insight on the birth of stars as well as detailed imaging of local star and planet formation.

As you might expect, a project like this was an international partnership between Europe, the United States, Canada, several countries from East Asia and the Republic of Chile. With 30 years of planning and 10 years of construction the entire project took thousands of scientists and engineers from around the world to complete. The total price tag was approximately $1.3 billion dollars and was split by the three sponsoring regions. Of the total cost the United States taxpayers contributed about $500 million.

The Llano de Chajnantor Observatory in Chile has been fully operational since March of 2013. ALMA combines dozens of these individual radio telescope dishes into a single observing instrument. What is amazing to me is that the resolution will be five times greater than that of the Hubble Space Telescope.   

Some facts about ALMA that intrigued me:

·         The observatory is accurate enough to detect a golf ball nine miles away.

·         This high altitude is one of the driest places on Earth. This means no clouds.

·         The dish design is almost perfect which prevent any loss of incoming radio waves.

·         Each ALMA antenna must be kept at a chilling -452 degrees Fahrenheit to prevent noise.

·         This will allow astronomers to see into distant gas clouds to study star and planet formation.

ALMA means “soul” in Spanish and “learned” or “knowledgeable” in Arabic. It will be interesting to see what information we can learn from our collective efforts in our search for knowledge about our universe. I find it a bit ironic that ALMA, in her otherworldly setting, sitting high atop a snow-capped plateau, surrounded by volcanoes, is also stepping up the search for alien life…somewhere…out there.

For images and information visit: http://www.almaobservatory.org/

My sources: Alma Observatory, Space.com, The Telegraph UK, www.phys.org, www.eso.org, , The Planetary Society, and en.wikipedia.org.  

Quintenary Star System: Anything But Ordinary

We’ve all heard about binary stars (one star revolving around another). The most popular binary stars are Mizar and its fainter companion star Alcor. To find them, look for the Big Dipper and find the handle; you’ll spot Mizar first as the middle star of the Big Dipper’s handle. Look closely and you’ll see Alcor right next to Mizar.

Harder to find are the trinary star systems, or triple star systems. It’s interesting to me because usually two of the stars form a close binary system while the third star orbits this pair at a distance in a much larger orbit. One such system is the Alpha Centauri star system with Proxima Centauri at a distance of 4.22 light years. It is the closest star to Earth beyond our own Sun.   

The Kepler Space Telescope observed KIC 2856960 for four straight years before astronomers seemed to have enough data to make a determination. But when three astronomers, Marsh, Armstrong, and Carter in the UK started digging into the numbers, they discovered the system was anything but ordinary. First they observed two stars in close orbit of one another: a binary system. The smaller star seemed to orbit the larger one every 6 hours. However, there appeared to be a third star that entered into the equation every 204 days. This was throwing off their results. As they diligently worked out their dilemma on paper, other astronomers became involved. It’s the fact that they could not find a precise set of masses and radii for the component stars. We can’t explain why this star system is producing an ‘impossible’ light curve.

As the team studied the data from KIC 2856960 they saw a small dip in brightness about 4 times a day and a larger dip every 204 days. Okay, not a big deal; it’s a triple star system, so let’s move on to other data. But they were drawn back to their results to look at it with even more detail. After all, this was tricky, and there were all sorts of things that threw off results, such as starspots and other stellar activity. The more they looked at the data, the more confusing things got. At first glance, it looked like a triple star system, but the stars’ orbits didn’t seem to fit. They kind of fit, but there were fluctuations in the data. So the team tried another scenario and found that a four-star system worked—a quintenary system—two sets of binary stars!

This is anything but ordinary, and further data needs to be collected, but it’s clear that this is not a simple, boring triple-star system. We just don’t understand it yet. Perhaps the Transiting Exoplanet Survey Satellite, or TESS, will be able to shed some light on this. TESS is scheduled to launch in 2017. Until then KIC 2856960 is likely to remain a mystery. Is this a quintenary star system? Is there a planet hidden in this system? Don’t you love a good mystery?

Recommended link:  http://www.atlasoftheuniverse.com/orbits.html

My sources: AtlasoftheUniverse.com, space.com, phys.org, pbs.org, atrobites.org, astronomy.com, and American Association of Variable Star Observers (AAVSO)  

Mordor Macula, Vader Crater, Nostromo Chasma…

By Jean E. Lane

New Horizons’ flyby of Pluto and Charon, its largest moon provided us with many incredible images. But the highly detailed images gave the New Horizons team an unanticipated problem: What do they call all those mountain ranges, plains, and craters?

What happens next is that the team intends to submit them to the International Astronomical Union (IAU), who is the official governing body for names of celestial objects. Here’s what’s currently being proposed to the committee; how about choosing names from Star Trek, Star Wars, Doctor Who, Firefly, Alien, and Lord of the Rings? The New Horizons team actually asked for submissions from the public, and they were only too happy to oblige. 

Since Pluto was named after a god of the underworld, the names must be drawn from underworld mythology. NASA offered the Cthulu regio (a large region with color variances). Also chosen was the name Balrog macula (meaning dark spot) which honored Lovercraft’s dark god and the underground demons from stories by J.R.R. Tolkein. 

All that’s wonderful news, but it’s Charon, Pluto’s moon, and the IAU rules permit names that reference “destinations and milestones of fictional space” as well as fictional spaceships and travelers. This notion grabbed the imaginations of many space fans, and their thoughts went directly to the iconic science fiction shows and movies that they revere.  

Thus, the suggestions were presented, and the unofficial names, of craters are Vader, Skywalker and Leia Organa. For the plains they propose names of Spock, Kirk, Sulu, and Uhura, which would dot the Vulcan Planum. How about the Tardis chasma that crosses the Gallifrey macula?  This name, of course is in reference to The Doctor’s (Doctor Who) vessel and planet. It also has been proposed that names from Alien, such as Ripley crater and Nostromo chasma, would be excellent choices. The name Serenity chasma in respect for Firefly also has a chance to become a real place on Charon. There’s room for one from Lord of the Rings, the giant Mordor macula at Charon’s North Pole.

Although they are nevertheless provisional, “We still have a decent chance of getting these names approved,” stated New Horizons planetary scientist Mark Showalter.  After all, the IAU has previously approved features on Saturn’s moon, Titan, named Frodo and Bilbo, and the first landing site on Mars is now called Bradbury’s Landing!

Ah, this is news that stirs the creative abyss of a science fiction or science “faction” heart!

References: NASA, The Planetary Society, Mashable.com, International Astronomical Union, EarthSky, Washington Post, and National Geographic

GLOBULAR CLUSTERS…What are they?

You may have heard the term “Globular Clusters” before, but exactly what are they?  According to the Planetary Society: “Like stellar time capsules adorning the periphery of galaxies, globular clusters contain some of the oldest stars in the universe.” Some of these star clusters may seem to have the appearance of galaxies. This is because they are a symmetrical system of stars with the highest concentration of stars near their own center and bound together by gravity. Imagine yourself on a world where the sky is always ablaze with the sight of hundreds of thousands of stars as bright as the full Moon. Most likely these stars would be the older, fainter, red and yellow stars.

The more dense globular clusters can be found in the halo of a galaxy, whereas the less dense galactic, or open, clusters are located in the disk of a galaxy. The clusters in the halo contain considerably more stars than the open clusters. Globular clusters are fairly common; there are about 157 of them currently known in the Milky Way Galaxy. Larger galaxies, such as our neighbor Andromeda, may have as many as 500. Moreover, the giant elliptical galaxies may have as many as 13,000 globular clusters.

The first globular cluster discovered was M22 in 1665 by Abraham Ihle, a German amateur astronomer. However, given the poor aperture ability of early telescopes, individual stars within a globular cluster were not resolved until Charles Messier observed M4, discovered in 1746. The designation before a number refers to the catalog where the discovery is listed. The letter “M” tells us it is listed in the Messier catalog, whereas “NGC” tell us it could be found in the New General Catalog by John Dreyer. The designation letter is something that I’ve wondered about and just learned more details in this research.

We have 157 cataloged globular clusters right in our own galactic neighborhood, the Milky Way. There are too many to list here, but our largest cluster is Omega Centauri (NGC5139) and second is 47 Tucanae, both of which can be observed with the naked eye under the right conditions., M4 and NGC6397 are both 7200 light years away. Some other noteworthy clusters are NCG104, NGC4833, M55, M69, and M13. There are so many of these beautiful star clusters - out there, waiting for you to discover.

Stunning images and more info at: http://www.astro.keele.ac.uk/workx/globulars/globulars.html

My sources: NASA.gov, en.wikipedia.org, spider.seds.org, astrosociety.org, hyperphysicis.phy-astr.gsu.edu, astro.keele.ac.uk, Britannica.com, The Planetary Society, ned.ipac,caltech.edu, and astronomy.com.          

 

 

 

 

 

 

 

 

 

                             

Does a Real-Life Death Star Exist?

Does a Real-Life Death Star Exist?

 

No, I’m not talking about something from the movies. That star would need to get close to a planet to destroy it. WR104, however, has the potential to burn worlds from thousands of light years away. This is Wolf-Rayet 104 located in the constellation of Sagittarius about 2,222 parsecs away. Okay, that’s about 8,000 light-years from us which may seem like a safe distance, but consider that WR104 is 25 times the size of our sun, very dense, and much, much hotter. Add to that mix the fact that this star is rotating rapidly and expelling its gases creating a spiral around it; it is dying.

At this level of brightness the radiation field around the star takes on a life of its own and plays a most unusual role; it sheds off the outer atmosphere of the star by photon pressure. Therefore, Wolf-Rayet stars are so luminous that they are literally flying apart! This creates a high-velocity stellar wind surrounding the star which first grabbed the attention of astronomers. Wolf-Rayet stars are very rare, only 230 have been discovered, so far, in our Milky Way Galaxy. Of these stars, half of them have a binary companion star which burns just as hot as the main star.

First discovered in 1998 by the Keck 1 Telescope, this star was photographed, studied, measured, and cataloged. Scientists were first taken by the size and beauty of this spiral image. They determined the diameter to be 160AU (Astronomical Units), which is 160 times the distance from Earth to the sun. Peter Tuthill, at the University of Sydney in Australia, has been studying WR104 for years. He realized it rotated in a circle every eight months and found one devastating fact: Earth looks down the axis of the system. We are not looking at it from an angle, but dead-on, like looking down the barrel of a rifle.  

Another fact which concerns astronomers is that WR104 is not a single star system, rather a binary system. It has another Class OB star locked in orbit with it. As they circle one another, plumes of streaming gas are driven from their surfaces creating a fiery, colorful pinwheel in space. Astronomers fear the fuse for this star is very short; it may explode within the next few hundred thousand years. When it does it may emit an intense beam or ‘gamma ray burst.’ It is impossible to predict whether or not it will actually create the dreaded gamma ray beam directed at Earth; the exact outcome is still unknown. Some reports say, “Not to worry,” others say, “Earth is in line with a death-star.”  I say, it’s a long time away; we have more important things to worry about until then.

For an image of WR104 visit: http://www.space.com/5081-real-death-star-strike-earth.html

My Sources: Astro Dept. at University of Michigan, nature.com/news, dailygalaxy.com, popsci.com, science.time.com, universetoday.com, space.com, and en.wikipedia.org