PK38-25.1 with a background galaxy.
I subscribe in email to a wonderful service really designed by graduate students for undergraduate students. Many of the articles they post are really interesting and I love following Astrobites. Today, in this article, they discuss planetary nebula and specifically a study done on Abell 70 a very interesting planetary nebula that is a binary system and as a side note it has a background galaxy at the top of it. You can see this at this APOD image here. What is fascinating is that in this system the central stars are a solar-temperature main sequence or subgiant star (G8IV-V) and a hot white dwarf (WD) companion. The white dwarf is really faint and was identified not by optical spectroscopy, but by UV imaging (see the article please).
This planetary nebula is in the constellation of Aquila and is primed for both visual observing and astro-photographic. It has a visual magnitude of 14.3 so in the right size scope, but it is challenging because of the star field and neither a OIII or Ultrablock filer helps much here. Here are some links about viewing these:
Jay McNeil Data found here.
Info on an observation found here. Here is a copy of the information from that site, Adventures in Deep Space:
|20 31 33.6; -07 05 19||Aql||Urano: 298||Mag: 14.3||Size: 42"|
|Another very curious planetary, not the least of it due to a galaxy shining through its northern edge (top in image to the right). |
Probably the toughest to find of Jay's list, due to an amalgam of stars in finder and eyepiece which would not lend themselves to easy asterisms; at least to my mind's eye! Neither my OIII or Ultrablock filters helped with this one. 4.8 Nagler (417x) used to bring out detail: Annularity glimpsed only with averted vision (otherwise a circular "blur"); northern edge only slightly brighter. No sign of central star. A very rewarding and challenging object.
So if your in for a challenge this summer and like planetary nebula then this can be a good challenge object for you. I am going to try for it this weekend and will hopefully have a succesful hunt. Here are some finder charts from Starry Night Pro to help. It is just above the Saturn Nebula (another great planetary nebula to view) and Messier 72 & Messier 73. Click on the image to make it larger. The star hops are from Al Bali, the end star in Aquarius. Good luck!