SN 2011fe

 DSO, Galaxy  No Responses »
Aug 282011
 

On 24 Aug 2011  the Palomar Tansient Factory detected a ‘star’ that wasn’t there the night before.  What the fully automated system found was the closest type Ia supernova in decades.  As the image below shows, the supernova is in Ursa Major’s Pinwheel galaxy (M 101).  (Click the thumbnail to blink the supernova.)

There are a couple of things that make this discovery special.  The first is how ‘young’ the supernova is.  Since the galaxy was imaged the night before and nothing was visible at that location, the supernova was caught within 24 hours of ignition.  Subsequent imagery shows the supernova is, as expected, continuing to brighten. 

The second thing that makes it special is its proximity.  The Pinwheel galaxy is only 21 million light years away.  The relatively close distance and the resultant increase in apparent brightness (the discovery image measured a 17.2) brings the object into the range of many more scientific instruments.  More telescopes equals more coverage.  Quickly changing events, such as associated with a supernova, could be missed waiting for the earth to rotate a large enough telescope into view. 

I took the supernova image Friday night.  It is a stack of nine 300 second exposures.  The stars magnitude at that time was 13.34.  The other image is an archive image of M 101 that I took in May 2009.  It is also a stack of nine 300 second exposures.

 Posted by at 12:43

The Queen’s hair pin

 DSO, Galaxy  No Responses »
Jun 132011
 

Coma Berenices is one of the few constellations that is named for an actual historical figure.  The story goes that after King Ptolemy of Egypt ( 246-221 BC ) left for battle, his new wife pledged to the goddess Aphrodite that she would cut off her long blonde hair as a sacrifice if he came home safe.  As word came that he was returning, she cut off her hair and placed the locks in Aphrodite’s temple.  The next day they were gone.  Once the King returned and saw that his wife had cut her hair he was furious, but the court astronomer/astrologer announced that the offering had so pleased the goddess that she had taken the hair and placed it in the sky for all to see.

Although the constellation Coma Berenices is rather small it is home to 8 Messier objects and a sizeable chunk of the Virgo cluster of galaxies.  It also has its own much more distant cluster of galaxies.  However, the galaxy in this image is not a member of either of those groups.   This is the ‘Needle Galaxy’ also known as NGC 4565. 

”]Conflicting data show the galaxy’s distance is between 20 and 50 million light years away.  Its total light is equal to about 3 billion suns.  Obvious in the image is the prominent dust lane that runs the length of the disk. This material appears to be a standard feature of spiral galaxies.  The Milky Way also has this obscuring dust lane; it is known as ‘The Great Rift’.  Also visible in the image is galaxy NGC 4562 at center bottom.

 This image is a stack of thirty 30 second exposures taken on the night of the 15th of May.

 Posted by at 19:39

In a galaxy far, far away…

 DSO, Galaxy  1 Response »
May 072011
 

This spiral galaxy (NGC 3972) is in the Ursa Major constellation.  In fact several galaxies are visible in the image.  Of course, all those galaxies lie well outside ours.  But, all the stars that you see in the image are members of the Milky Way.  All but one. 

”]The distance to NGC 3972 is estimated to be 13.6 Mpc. That’s about 44,363,200 light years.  At that distance NGC 3972’s stars are so far from us that their combined light merge into the spiral form that we see.    However, the star indicated by the tick marks is a member of NGC 3972.   The only reason that we see that individual star is that it has very violently exploded as a supernova.

SN 2011by, a type 1a supernova, was discovered by Chinese astronomers on April 26th 2011.

This image was taken last night (6 May 2011).  It is a stack of 20 thirty second exposures.

 Posted by at 09:02
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