Galactic Nebula IC 2120

IC 2120
IC 2120: H-II region, no PN in Auriga; 500 mm Cassegrain f=3625mm / f7.2; SBIG STL11K; 105+3*30 min LRGB; Bernese Highlands; © 2011 Radek Chromik [32]


The French astronomer Camille Guillaume Bigourdan discovered this nebula on 8 December 1890 using the 12.4 inch refractor at Paris Observatory. He cataloged the nebula as number 262 and noted: «Magnitude 13.4-13.5, clearly nebulous. It was found on 8 December 1890 and was originally thought to be the comet Spitaler (1890 VII).» [363] John L. E. Dreyer included the nebula 1910 as IC 2120 in his «Second Index Catalogue of Nebulae and Clusters of Stars». [315]

IC 2120
IC 2120: Same image section in four different photographic surveys [147]

Physical Properties

This object caused a bit of confusion: The «Strasbourg-ESO Catalog of Galactic Planetary Nebulae» published in 1992 lists IC 2120 as a possible planetary nebula under the designation PK 169-0.1. [141] In the 2001 edition of the same IC is listed as a misclassified PN with the note «compact H-II region». [146] Simbad also offers this version. [145] The «NASA/IPAC Extragalactic Database» (NED) still explains IC 2120 as a sighting of comet 113P/Spitaler, which was mistakenly mistaken for a nebula. [194]

As you can see in the pictures, the small, round shape of IC 2120 with the star in the middle really looks like a planetary nebula, but it is a compact H-II region. Simbad gives 1388 parsecs (about 4500 light years) as the distance. [145] Other sources give 0.9 kpc to 1.86 kpc. [365]

Revised+Historic NGC/IC Version 22/9, © 2022 Dr. Wolfgang Steinicke [277]
Designation IC 2120
Type NF
Right Ascension (J2000.0) 05h 19m 10.3s
Declination (J2000.0) +38° 11' 06"
Identification, Remarks Comet Spitaler 1890!

Finder Chart

The galactic nebula IC 2120 is located in the constellation Auriga, which is best visible from August to April.

Finder Chart Galactic Nebula IC 2120
Galactic Nebula IC 2120 in constellation Auriga. Charts created using SkySafari 6 Pro and STScI Digitized Sky Survey. Limiting magnitudes: Constellation chart ~6.5 mag, DSS2 close-ups ~20 mag. [149, 160]

Objects Within a Radius of 15°