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NGC 2129 (4,046 of 18,816)


oc gc pln bn dn gx gxcl ast aka lost




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NGC 2129

NGC 2129, Cl Collinder 77, C 0558+233, Ocl 467, COCD 84, VIII 26, h 372, GC 1325

RA: 06h 01m 6s
Dec: +23° 19′ 24″

Con: Gemini
Ch: MSA:156, U2:136, SA:5

Ref: SIMBAD, Collinder (1931), DAML02, Archinal&Hynes (2003)

(reference key)

Type: open cluster, 13m

Mag: B=7.31, V=6.7

Size: 5′
PA: ?

Historical observations

William Herschel (c.1784)

Synonyms: H VIII-026

Discovered in 1785 by William Herschel with an 18.7-inch f/13 speculum telescope. He called it "a cluster of stars of various magnitudes, not very rich, 6' or 7' diameter."

Published comments

Trumpler, R.J. (1928)

Trumpler (Lick Obs Bul, Vol 14, No. 420) gives the diameter as 7' and the class as 2 3 p.

Photo index

Photo Index by Jim Lucyk: Observer's Guide (Astro Cards) 11-12/88 p24.

Sulentic & Tifft (1973)

The RNGC (Sulentic and Tifft 1973) notes that this is a 7.0 mag open cluster.

Modern observations

Walter Scott Houston

Houston notes that this cluster is about 7' in diameter and contains more than 40 stars, the brightest being 7.4 mag. He writes that it is "a nice sight in any telescope, with two much brighter (8th mag) stars in its midst."

Ken Reeves

Ken Reeves, in "SACNEWS On-line for February 1997", observing with a 10-inch f/4.5 scope, notes: NGC 2129 (06 01.0 +23 18) This open cluster is a nice tight knot of stars at 70X with two pretty bright stars. I counted about 20 stars with 4 levels of brightness. On the east side is a nice double star. In the center is a bright star that I saw as yellow, all the other stars looked pretty much white.

Steve Coe

Steve Coe, observing with a 13" f/5.6, notes: "Pretty bright, pretty small, not compressed, 22 stars counted at 100X. Several nice pretty bright stars involved."

Ancient City Astron.Club (1980)

Listed by the Herschel Club, described as "5' in size, 13 stars counted in this broken chain-like arrangement of stars, scattered somewhat loosely. 8-inch, 48x."

Tom Lorenzin, in the electronic version of "1000+ The Amateur Astronomers' Field Guide to Deep Sky Observing", notes: "6.7M; 7' diameter; 30-plus 7M and dimmer members; bright star to S; 30' to E is 4M 1 GEM."

Brian Skiff

6cm - two prominent m7.5 *s aligned N-S w/some hint of the rest of the cl.

15cm - fairly br but poor cl surrounding two m7,8 *s. 25-30 *s in 4' diam to radius of m10.5 * isolated on W edge. close WSW of Nrn br * is f close pair res @ 140x. nice 50x/1.2-deg fld. BS, 4Feb1991, Anderson Mesa.

25cm - 180x: 5' diam, 35 *s. m8 * on S, m8.5 N end. nice & br.

30cm - 21 *s in 4' area. loose & poorly concen.

Contemporary observations

Magda Streicher

31 Jan 2008

NGC: 2129 - Gemini

Open Cluster

RA: 06h00m41.0 - DEC: +23o19'04"

Magnitude: 6.7 Size: 7'

Tel: 12" S/C 218x Date: 31 Jan 2008 Site: Alldays - good

Lovely face looking back at you, amazing. Two lovely blue white stars around 7.5 magnitude in a NS direction stand out against a field of fainter stars. Very much in a round shape, contains more or less 15 stars in total. Beautiful.

(no date)

Alldays (22.50S, 20.12E, 770m).

12-inch f/10 SCT (95x, 218x)

Lovely cluster which had two 7 magnitude star dominate the heart. Resolved into a loose scattering of a dozen or so faint stars. The cluster is cut in two groupings, with a dark area with the southern part slightly bigger and brighter. The east more cut down in star light.

Tom Bryant

2010 2 20 21:16:46

Observing site: Little Tycho Observatory

Telescope: C-8

[6h 1m 0s, 23 18m 0s] Three bright stars, with a backgound haze of much fainter ones.

Richard Ford

2013 February 6th, Wednesday

Location:Blesfontein Guest Farm,Sutherland.


Sky Conditions:The most crystal clear sky possible.Dark moon and stars magnitude 6 and fainter are visible with the naked eye.Excellent clean sky,limited star flickering and brilliant objects.

Instrument:12-inch Dobsonian.

This open cluster is an irregular cluster which consists of 7.5 magnitude to 8.2 magnitude stars which is running in an east-west direction and that the stars in this cluster is well detached with three 7.4 magnitude stars running in the shape of a triangle.In this open cluster most of the stars are nearly the same brightness as each other.This open clusters stars are slightly concentrated towards each other.This open cluster measures 12'x 9.2'with P.A:East/West.Chart No.207,NSOG Vol.1.

Favourite lists

Lacaille's catalogue

The Messier objects

Dunlop's catalogue

The Bennett objects

The Caldwell list

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