Hoag's object (Serpens)

Object: Constellation: Coordinates: Size: Brightness:
Hoag's object
(PGC 54559)
Ser 15h17m / +2135' 0.28' x 0.28' 16.4mag

The ring galaxy PGC 54559 (Hoag's object) in the constellation Serpens on May 25 / 26, 2020. The non-typical galaxy is named after the American astronomer Arthur Hoag (1921-1999) who discovered it in 1950 and identified it as either a planetary nebula or a peculiar galaxy. A ring of young hot blue stars with an apparent outer diameter of 45" (121,000 light-years) circles the older yellow nucleus with an apparent outer diameter of 6" (17,000 light-years) of this ring galaxy. Hoag's object is approximately 600 million light-years from Earth (source: Wikipedia).

Fourty-eight 3 minute exposures at ISO 800 were added for this shot with the DeepSkyStacker software (resulting in a 2 hour 26 minute exposure) and the final image processing was done in Photoshop.
Equipment: Canon EOS 450D Baader modified camera, TeleVue Paracorr Type II coma corrector, 16" f/4.5 "Ninja" dobsonian telescope riding on a dual-axis Tom Osypowski equatorial platform, Lacerta MGEN autoguider, Lacerta off axis system (field of view comparison: image of the moon with the same equipment).

Search chart 1 for Hoag's object. Map © 2020 "The Mag-7 Star Atlas Project", www.siaris.net. Map is slightly modified. The map can be downloaded here .

Search chart 2: Starhopping from the constellation Corona Borealis to Hoag's object with a 50 mm viewfinder. After closing in on Hoag's object and centering it with chart 2, use the photograph at the top of the page (which measures just 24' x 36') to identify stars close to the object. None of the stars in search chart 2 can be seen in the photograph at the top of the page (the field of view of the photograph is too small).