Monkey Head Nebula (NGC 2175)

NGC 2175
NGC 2175: Galactic nebula in Orion; 500 mm Cassegrain f=3625mm / f7.2; SBIG STL11K; 90+3*30 min LRGB; Bernese Highlands; © 2011 Radek Chromik
NGC 2174
NGC 2174: Monkeyhead Nebula in Orion; Takahashi TSA-120 f=900 mm; Canon EOS 20Da; 8 x 8 min, ISO 800; Glaubenberg; © 5. 2. 2011 Jonas Schenker [34]

History

NGC 2175 was probably sighted before 1654 by the Italian astronomer Giovanni Battista Hodierna. Hodierna discovered many of the nebulae known today, but his 1654 publication was little known outside of Sicily, so it was not known by Messier, the Herschels, and Dreyer. It was only rediscovered in 1980.

In 1857, the nebula-shrouded open star cluster was rediscovered by the German astronomer Christian Bruhns. According to John L. E. Dreyer he described it as an 8th magnitude star shrouded in a nebula. On 6 February 1877, French astronomer Édouard Stephan pointed his telescope at this point in the sky and discovered «a very faint nebula between three very faint stars», which later was recorded as NGC 2174. Its coordinates and description match a bright node in the northwestern part of the nebula. NGC 2174 is often mistakenly used for the entire nebula and NGC 2175 for the open star cluster. On 11 February 1890, the French astronomer Guillaume Bigourdan recorded a «very faint, very large, diffuse nebula» whose coordinates with IC 2159 point to a southern part of the whole nebula. He mistakenly believed that the nebula NGC 2175 listed in the New General Catalogue, published two years earlier, referred to the bright node east of the star HD 42088 and corrected its right ancension in the second Index Catalogue, published in 1910. [196, 313, 315]

Physical Properties

NGC 2175 is a young star cluster and active star-forming region enveloped in an H-II region. The radio source 3C 153.1 is also located here. The distance is about 1.6 to 2.2 kpc, about 5200 to 7100 light years. [146]

Revised+Historic NGC/IC Version 22/9, © 2022 Dr. Wolfgang Steinicke [277]
Name RA Dec Type bMag vMag B-V SB Dim PA z D(z) MD Dreyer Description Identification, Remarks
NGC 2174 06 09 00.3 +20 38 26 EN 3.5 × 2 2.000 eF, bet 3 vF st CED 67A; knot in N 2175
NGC 2175 06 09 38.6 +20 29 18 EN 40 × 30 2.000 * 8 m in neb (Auw No 21) GC 1366; LBN 854; OCL 476
NGC 2175 S 06 10 54.0 +20 36 36 OCL 5 * 8 m in neb (Auw No 21) GC 1366; Lund 1182; near N 2175
IC 2159 06 09 57.0 +20 25 54 EN 2.000 vF, vL, dif CED 67B; in N 2175

Finder Chart

The galactic nebula NGC 2175 is located in the constellation of Orion, which is best visible from October to February. Turn the card upside down and you will see the monkey head in the DSS section.

Finder Chart Monkey Head Nebula (NGC 2175)
Monkey Head Nebula (NGC 2175) in constellation Orion. 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]

Visual Observation

300 mm Aperture: In the 21 mm Ethos eyepiece the nebula is invisible without O-III filter. In the O-III filter it turns out to be a large, diffuse, structureless nebula around the bright star HD 42088. — 300 mm f/4 Popp Newton, Titlis 3020 m. a.s.l., SQM 21.20, 30 October 2022, 00:20, Bernd Nies

Objects Within a Radius of 15°

References