Galaxy – Page 2 – Pear Tree Observatory

I haven’t had the chance to do much imaging lately so I stepped into my WABAC machine and dug up an image from the archive.

M-87

The large nebulous object in the image is M87, a very large elliptical galaxy visible in the constellation Virgo. Elliptical galaxies are visually quite un-remarkable. Spherical, featureless and usually devoid of gas, these galaxies consist of very old stars. The lack of gas results in little to no stellar creation. All this leads to a fairly bland appearance.

So, why did I take a set of images of this one?

Every once in a while, I will try to image something unusual just for the challenge. Most of the time the local light pollution combined with the small aperture of my telescope prove too much for the intended target.

But, not this time.

Although discovered in 1781 by comet hunter Charles Messier it wasn’t until 1947 that the galaxy was identified as a powerful radio source. Photography showed a visible jet of material and it was suggested the jet was the source of the radio energy. Further investigation showed the galaxy was a very strong X-ray and Gamma ray source as well. Hidden deep within the halo of stars that make up M87 is a beast. A supermassive black hole at the center of the galaxy powers the jet and provides the energy for the X-ray and Gamma ray emissions. My equipment cannot image the black hole, the X-rays or Gamma rays, so my personal challenge was to image the jet.

I had tried several times before but it always seemed that I could not capture enough light. I took a lot of exposures and stretched the combined stack well beyond a pleasing image but just couldn’t find it. I kept thinking that I would have to get a larger telescope. (I do need a larger telescope.)

M-87 jet

However, this time while processing the images, I accidently slid the stretching control the wrong way.
It was then the jet revealed itself. The jet is only 5000 light years long. The galaxy is much much larger. So only by reducing the overall brightness does the jet, buried deep in the galaxies glow, finally become visible. I had been looking too far from the galaxies core.

The image is ten 300 second exposures.

Although the irregular galaxy M 82 is approximately 12 million light years from the Milky Way, it is considered a close neighbor. On the 21st of January that neighbor became the talk of the neighborhood when it was found sporting a brand new supernova. Of course, in Astronomy, brand new is a relative term. It is a sobering thought to realize this several week long pulse of light has been traveling for 12 million years and will pass us by and continue on out into the universe.

It was first noticed by students using one of the 0.35 meter reflectors at London University’s observatory. Threatening weather forced a cancellation of the regularly scheduled instruction for a quick demonstration of CCD usage. The students choose M 82 as the target. A check of the image showed a star that the instructor did not remember from earlier observations. A quick search of archival images verified the interloper as transient, and the rest is history.

SN 2014j in M 82

As the announcement of a potential supernova (PSN J09554214+6940260) spread, many telescopes turned their attention to M 82. Spectroscopic images showed it to be a type 1A supernova a couple of weeks shy of maximum brightness.

My ‘after’ image was taken on the evening of the 22nd of January. It measures a magnitude 11.2 but that is too bright as I cannot measure the star without including light from the galaxy. Measurements taken on the 31st show a magnitude of 10.5, but modeling shows that it will peak during the first couple of days in February, so it won’t get much brighter.

By pure chance I took the ‘before’ image on the 3rd of January. Since the image on the 3rd was taken for 30 seconds through a luminance filter, I used the same settings on the 22nd in an attempt to match the two for the animation. I am surprised how close the images match.

The Great Hercules Cluster, viewed through clear dark skies, is just large enough and bright enough to be visible to the naked eye. First observed by Edmond Halley (of comet fame) in 1714, and later cataloged as number 13 in Charles Messier’s list of not-comets, the cluster, as the common name implies, is located in the constellation of Hercules.

By offsetting the cluster in the image I was able to include several other objects. Each has a vastly different distance providing a somewhat three dimensional view to this small patch of the night sky.

The bright star (HIP 81848) near the upper left is an orange (K2 class) star with a magnitude of 6.86, putting it just under naked eye visibility. While none of the objects we will discuss are close to us, this star is the closest. It lies well within the Milky Way at about 1,832 light years (LY) from the sun.

Next comes the globular cluster. It lies 27,400 LYs from the center of the Milky Way, also putting it within our galaxy. Globular cluster orbits are not confined to the disk of the galaxy and M 13’s current position is above the galactic plane. Its 300,000+ stars lie about 25,100 LYs from the sun.

The Great Hercules Cluster (M 13) [C:40x30s]

Next on the hit parade is NGC 6207, the bright galaxy in the upper right corner of the image. It is classified as a SA(s)c spiral galaxy. At a magnitude of 12.2 this is a challenge to see with a small telescope but should be visible as a faint patch of light in an 8″ scope.

(NGC 6207) detail

What appears to be a very bright galactic core is, in fact, a fortuitously positioned star in our galaxy. Not visible here is NGC 6207’s own collection of globular clusters orbiting its center. The galaxy is located approximately 37 million LYs from us.

The most distant object in our discussion is IC 4617, the small faint galaxy slightly above and to the right of M 13. This Sbc class spiral galaxy comes in at a magnitude of 15.9 making it a much more challenging visual target.

(IC 4617) detail

It has a reported red shift of 0.036. I was able to get several red shift calculators to agree at a distance of about 150 mega-parsecs. And since a parsec is 3.26 light years in length, our long distance champ is roughly 489 million LYs away.

The base image is a stack of 40 thirty second exposures taken on the evening of May 28th.

It is not unusual to see grand spiral designs from inside the dome of the Pear Tree Observatory. I took this image of NGC 3938 on the 1st of March this year. Located in the constellation of Ursa Major, this spiral is located approximately 43 million light years away. With a diameter of 67,000 LYs it is about 2/3rds the diameter of the Milky Way galaxy.

[C:30x120s]

What is unusual is to see a grand spiral design inside the dome of the Pear Tree Observatory. Although the direction of rotation is opposite and the difference in scale is astronomical, the pattern is unmistakable. Obviously, some insect found the environment inviting just under the lip of the rotating portion of the dome. The eggs sit on top of individual stalks each about three sixteenths of an inch high. The diameter of this spiral is about the same as a nickel. My guess is the temperature in the uninsulated dome doomed the eggs as they have not hatched after several months.

NGC 4631 is a spiral galaxy in the northern constellation Canes Venatici (the hunting dogs) seen edge-on. It is one of a close trio of bright galaxies; two of which are visible in this image. All three have been graviationally ‘involved’ with each other in the past. That interaction is evident in the distortion of the large galaxy visible here and the third galaxy off the image to the lower left. The asymmetry about the central bulge and the prominent bright region of newly forming stars on the lower left edge has given the galaxy the common name of ‘The Whale Galaxy’.

”]This image is a stack of thirty 120 second exposures taken on the evening of the 26th of March. The dimmest star in this image is a magnitude 20.3 and nothing in this image is visible to the naked eye. Unlike most of my imagery, north is up and east to the left.

Pear Tree Observatory
temp:	43℉ (6℃)
humidity:	78%
wind (MPH):	From the NNW at 0
pressure:	30.1 inHg
station:	KFLVALPA4
hardware:	Davis Vantage Pro 2
software:	VWS V15.00
updated(L):	24-11-21 03:58
updated(Z):	24-11-21 09:58

Pear Tree Observatory

M-87

Supernova SN 2014j

Far, Farther, Farthest, Farthest-er

Patterns

NGC 4631 – Ahab’s Bane