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EntityQ1047055· pop 30· linked from 335 articles

open cluster

Key facts

Right ascension
06 01 06.5
Declination
+23 ° 10 ′ 20 ″
Distance
7,200 ly (2,200 pc )
Apparent dimensions v
2.5 MOA
Estimated age
10 Myr
Other designations
NGC 2129, C 0558+233, OCl 467, OCISM 10, KPR2004b 84.
Constellation
Gemini

via Wikipedia infobox

Wikidata facts

Instance of
open cluster
Constellation
Gemini
Distance from Earth
1515
Image
NGC 2129 DSS.jpg
Show 11 more facts
catalog code
[KPS2012] MWSC 0704
discoverer or inventor
William Herschel
time of discovery or invention
1784-11-16
apparent magnitude
6.7
Commons category
NGC 2129
right ascension
90.2792
declination
23.3217
radial velocity
11.8
epoch
J2000.0
right ascension component of proper motion
-0.71
declination component of proper motion
-1.53
Sources (3)

via Wikidata · CC0

~1 min read

Encyclopedic overview

NGC 2129 is an open cluster in the constellation Gemini. It has an angular diameter of 2.5 arcminutes and is approximately 2.2 ± 0.2 kpc (~7,200 light years) from the Sun inside the Local spiral arm. At that distance, the angular size of the cluster corresponds to a diameter of about 10.4 light years. NGC 2129 is a very young cluster whose age has been estimated at 10 million years. It was discovered by William Herschel on November 16, 1784

The group is dominated by two close B-Type stars, HD 250289 (B2III) and HD 250290 (B3I). With the two stars sharing the same proper motion and radial velocity it is likely that the two constitute a binary system.

Excerpted from Wikipedia’s “NGC 2129” article, available under the CC BY-SA 4.0 licence.