The UFO Galaxy (NGC 2683)[C:199x60s]
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Once again the diminutive FOV of my system does not lend itself to extended objects. Thus, it does not do the Heart Nebula justice. In fact this image only shows the central part of the heart shaped portion of IC 1805. However, it does show the small very young cluster of stars (Melotte 15) that ‘lights up’ the nebula. Several of the stars have estimated masses in excess of 50 times that of the Sun and it is those stars whose extreme output provides the energy to excite the surrounding hydrogen cloud into emitting the familiar red light. The energy is also what is sculpting the surrounding cloud into the fanciful shapes visible in the image.
![The Heart Nebula (IC 1805 detail) [Ha:67x120s ]](https://ptobservatory.com/wp-content/uploads/2016/11/str_crv_dcv_ddp_IC-1805.jpg)
The Heart Nebula (IC 1805 detail) [Ha:67x120s ]
Chart generated with Cartes du Ciel
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The constellation Cygnus (the Swan) has 5 bright stars that forms the shape of the bird in flight. The star at the intersection of the swan’s wings and body is named Sadr; the Arabic word for chest. The Bayer designation is Gamma Cygni (γ Cyg, γ Cygni).
The constellation is bright and easy to identify in the Northern sky. What is not so easy to see is the very large emission nebula located near γ Cyg. Although γ Cyg lies near the center of the nebula, it is only a chance alignment. The star lies about 1,500 ly’s from Earth but the estimated distances to the nebula average about 3,000 ly’s. |
 By IAU and Sky & Telescope magazine (Roger Sinnott & Rick Fienberg) |
![(IC 1318)[C:60x60s]](https://ptobservatory.com/wp-content/uploads/2016/09/lvl_crv_ddp_IC-1318.jpg)
(IC 1318)[C:60x60s]
Since γ Cyg is so bright, I positioned it out of the FOV to prevent it overwhelming the image. Also, this image is only a small part of the nebula since my telescopic field of view is much too small to view the entire object. The dark area that crosses the image is not a lack of stars but is instead a very dense part of the nebula which blocks the background light from reaching us.
Chart generated with Cartes du Ciel
NGC 281 is an HII nebula in the constellation Cassiopeia. Named only ‘recently’, it has been given the common name of “Pacman Nebula” due to its remote resemblance (if rotated correctly) to the video game character. The nebula is about 80 light years in diameter at its estimated distance of 10,000 light years.
![Pacman Nebula (NGC 281) [Ha:60x120s]](https://ptobservatory.com/wp-content/uploads/2016/09/d_str_NGC-281_3.png)
Pacman Nebula (NGC 281) [Ha:60x120s]
Chart generated with Cartes du Ciel
Quite often, astronomers adopt a common name for a celestial object based on what it ‘looks’ like to them. Just as often it takes a very vivid imagination to see what the astronomer saw. Most of the common names were based on photography using fairly primitive cameras, equipment and techniques. Modern imagery taken with today’s CCD cameras and processed with computer software, look nothing like the common names associated with the celestial objects.
This is not one of those times.
This nebula quite obviously has a bubble blown in it. The star right of the bubble’s center and slightly above and right of the bright knot of gas is the guilty party. This young star has about 20 times the mass of the Sun and its energy output is several hundred thousand times that of our star. This is what is blowing the bubble in to the surrounding molecular cloud. The cloud of gas and dust is more dense on the right side of the bubble and thus is constraining the expansion more on that side.
![Bubble Nebula (NGC 7635)[Ha:76x35s]](https://ptobservatory.com/wp-content/uploads/2016/09/g_lvl_crv_dcv_ddp_NGC-7635.png)
Bubble Nebula (NGC 7635)[Ha:76x35s]
Chart generated with Cartes du Ciel