August 11, 2018

NGC 3324 and Nebula (Spring & Summer 2018)

Cluster NGC 3324 sits just northwest of Eta Carinae, from our perspective. Astronomers have wondered whether it is part of the Eta Carina nebular complex or not, because it sits so close by, but studies suggest the cluster and the Eta Carina complex are part of the same. The cluster of stars that is NGC 3324, just above center of the nebula here, contains three O-type stars known as HD 92206 B, A, and C (from left to right). 92206 A and B are type O6.5 V.  92206 C appears to be O7.5 V with a close binary companion of type BO V. These stars light up the emission nebula, hollowing out a bubble with their strong stellar winds and UV radiation. A, B, and C are each X-ray sources. Source. This study found about 500 stellar X-ray sources in the area, about 150 of which are probably young stars belonging to NGC 3324 and to another local cluster. These clusters probably comprise several hundred stars each. Only a few show up in the image above, however.

Data for this image comes from Martin Pugh's observatory, and is SHO = 10, 14, 10 x 1800" with the RCOS 12.5" telescope.

August 5, 2018

IC 5070, The Pelican's Eye (August 2018)

This image is 12x1800" with the SXVF-H9 through the Synta-ONTC8 and a 6nm Astronomik H-alpha filter.  Of course, this is the most interesting portion of the Pelican Nebula.  Those of you who know where to look can find a number of Herbig-Haro objects in this image.  Here is a good identification page from a very similar (but even deeper) image: .

NGC 6910 in H-alpha (August 2018)

This image was taken with an H-alpha filter to capture the background clouds, but the subject of the image is NGC 6910, the cluster of stars in the middle.  Sometimes it is called the Rockinghorse Cluster, and it does suggest that shape when viewed from the top right corner of the image (that is, from the northwest).

This image is 9x1200" with the SXVF-H9 through the Synta-ONTC8 at f/4.95 and an Astronomik 6nm H-alpha filter.

IC 5146, the Cocoon Nebula (August 2018)

This target in the constellation Cygnus carries emission signal, but it not strong.  What you see here is the H-alpha emission.  In full spectrum images, though, much of the nebular glow is reflection.  The bright star in the middle is a young, B-type star that powers the nebula.  It is surrounded by young stars forming from the disrupted dust and gas in this region.

This image is 9x1800" with the SXVF-H9 through the Synta-ONTC8 f/4.95 reflector.

July 29, 2018

NGC 6193 and 6188 in Ara (Spring & Summer 2018)

Here is a beautiful region of the constellation Ara in the southern hemisphere.  Near the top is star cluster NGC 6193.  The cluster is dominated by what look like two bright stars.  The lower star is HD 150135, an O-type star that burns very hot and is much larger than our sun.  The upper, brighter star of the two, however, HD 150136, is special.  HD 150136 is a triple system of O-type stars with masses of 62.6 ± 10, 39.5 ± 6.3, and 33 ± 12 solar masses, for a total of 102 ± 16 solar masses.  Source.  That's a big star.  Moreover, the two larger components are in a close orbit of 2.67454 days.  Same source.  That's so close the stars must be almost touching.  It's no wonder they generate fireworks, including X-rays.  The system generates enough UV radiation to light up this cloud, NGC 6188, including the ionization front shown in this image.

Data for this image comes from the 12.5 RCOS system in New South Wales.

July 20, 2018

Eta Carinae and Neighbors (Spring 2018)

This is such a fascinating field.  In the center shines the star Eta Carinae, a giant luminous blue variable star and its companion that together partly power up all the emission nebulae you see here.  In the upper left is cluster Trumpler 15, upper center Trumpler 14, and around and down from Eta Carinae the large cluster Trumpler 16.  Sprinkled throughout the field are Bok globules and globulettes.  In a few places, such as just to the left of Trumpler 14, you can find Herbig-Haro objects. I've studied the field quite a bit, and I'm still learning.  I recommend the entries on this area in Kanipe and Webb's Annals of the Deep Sky.

This image was constructed with excellent data gathered by my friend Martin Pugh at New South Wales, Australia.  See his website here.  The telescope is a 12.5" RCOS, the camera a SBIG 11000M, and data for this image is in narrowband as follows: 13x1800" + 3x1200" (Ha); 14x1800" (OIII); 14x1800" (SII).

July 4, 2018

Omega Centauri (Spring 2018)

Here is the Milky Way's largest star cluster: 10,000,000 or so stars and maybe a black hole (or not, a later study says), and perhaps the whole thing is the stripped core of a small galaxy.  It's also quite close, just 15,800 light years away.  The cluster is around 90 light years wide.  It is one of most amazing things I've ever seen in a telescope.  I observed it with a 15" f/5 Newtonian reflector from the HAS dark sky site in Columbus.  It is ablaze with stars!

I'm pleased that this image shows so many stars.  It gives some idea of the vastness one senses through the telescope.  This image is an LRGB= 5;6;6;8x600" with a SBIG 11000M camera through a 12.5" RCOS telescope in rural New South Wales.  Data was gathered by Martin Pugh who hosts an observatory there (details at