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NGC 129
Sign in to saveAlso known as New General Catalogue 129
open cluster of the constellation Cassiopeia
Key facts
- Right ascension
- 00 30 00
- Declination
- +60 ° 13 ′ 06 ″
- Distance
- 5,450 ly (1,670 pc )
- Apparent dimensions v
- 21'
- Estimated age
- 76 millions years
- Other designations
- Collinder 2
- Constellation
- Cassiopeia
via Wikipedia infobox
Wikidata facts
- Instance of
- open cluster
- Part of
- Milky Way
- Constellation
- Cassiopeia
- Distance from Earth
- 1625
- Image
- NGC 0129 DSS.jpg
Show 11 more facts
- apparent magnitude
- 6.5
- catalog code
- [KPS2012] MWSC 0053
- Commons category
- NGC 129
- discoverer or inventor
- William Herschel
- time of discovery or invention
- 1788-12-16
- right ascension
- 7.5000
- declination
- 60.2183
- radial velocity
- -36.0
- epoch
- J2000.0
- right ascension component of proper motion
- -0.51
- declination component of proper motion
- 0.10
Sources (1)
via Wikidata · CC0
~1 min read
Encyclopedic overview
NGC 129 is an open cluster in the constellation Cassiopeia. It was discovered by William Herschel in 1788. It is located almost exactly halfway between the bright stars Caph (β Cassiopeiae) and γ Cassiopeiae. It is large but not dense and can be observed by binoculars, through which the most obvious component is a small triangle of stars of magnitude 8 and 9, located in the center of the cluster.
NGC 129 contains several giant stars. The brightest member of the cluster is DL Cassiopeiae, a binary system which contains a Cepheid variable with a 8,00 day period. Using the fluctuations of the brightness of DL Cassiopeia from 8,7 to 9,28, Gieren et al. in 1994 determined the distance of NGC 129 to be 2034 ±110 pc (6.630 ±360 ly), much larger than the distance obtained by Turner et al. (1992), who obtained a distance of 1,670 ±13 pc from ZAMS fitting of the cluster. A possible cause of this difference is the different level of obstruction of light and star reddening of the stars of the cluster. One more cepheid variable, V379 Cas, is also a possible member of NGC 129.
Excerpted from Wikipedia’s “NGC 129” article, available under the CC BY-SA 4.0 licence.