32 31 30 29 28 27 26 25 24


IC 2177



Abell 31 (PK 219.1+31.2 ) Planetary Nebula in Cancer

RA= 8 hrs 54 min; Dec = 8 deg 54 min

Date & Site:

Imaged over 3 nights beginning on 2/28/17; Carlsbad, CA

Conditions: temps in the low 50's; clear, average seeing


Telescope: TEC 140 940 m at f/7

Guider: SBIG guidehead/Hutech OAG5

Mount: Losmandy G-11/Gemini I
Camera: ST-10XME; CFW10; Astrodon Ha (3nm), O3 (3nm) and N2 (3nm) filters



This object was discovered in 1955 by George Abell and appears in his catalog of planetary nebulae. Also known as Sharpless 2-290, this is a very ancient and large planetary nebula. It is also very faint and requires extremely long exposures to pull this out from the background. Abell 31 is characterized by strong molecular hydrogen and oxygen emissions, and as with many planetary nebula, ionized nitrogen (N2), particularly in the object's outer shell.

To create this false color image, I mapped red to N2, green to Ha, and blue to O3.

Exposures: 4 hrs through each narrowband filter (15 minute subs) for a total of 12 hours.

Abell 31 is 2,000 light years away.

(image reduced to 60% of original size)

FOV = 52 x 35 arc minutes

Back to Images