NGC 1252 is a metal-poor, open cluster remnant located in the constellation Horologium, containing around 20 stars. It was discovered in 1834 by John Herschel. It was described by John Louis Emil Dreyer as an 8th-magnitude star surrounded by a group of 18 or 20 stars. Stars TW Horologii and HD 20286 were once considered to be part of NGC 1252, but this is now not likely.[1]
| NGC 1252 | |
|---|---|
 NGC 1252 as observed by the Digitized Sky Survey | |
| Observation data (J2000 epoch) | |
| Right ascension | 03h 10m 47s[1] |
| Declination | −57° 45′ 18″[1] |
| Distance | 2,100 ly (640 pc)[2][note 1] |
| Apparent magnitude (V) | 12.58[3][note 2] |
| Apparent dimensions (V) | 7.2″[4] |
| Physical characteristics | |
| Radius | ~13 ly (4.0 pc)[5] |
| Estimated age | 3000.00±1000.00 Ma[6] |
| Other designations | ESO 116-11[7] |
| Associations | |
| Constellation | Horologium[4] |
| Galaxy | Milky Way |
Due to the nature of the object, it has been given different classifications: according to Bouchet & Thé (1983), it is an open cluster at around 500 million years old located 470 parsecs away, with a diameter of 8 parsecs,[5] while Baumgardt (1998) found it to be an asterism.[8] Pavani, Bica, and Dutra et al. (2001) put the age at 3 billion years old and distance at 1,000 parsecs.[6] It is also approximately 900 parsecs below the galactic disc.[1]
Two structures are located nearby: the Tucana-Horologium association and the Hyades Stream.[1]
Notes
editReferences
edit- ^ a b c d e de la Fuente Marcos, R.; de la Fuente Marcos, C.; Moni Bidin, C.; Carraro, G.; Costa, E. (4 July 2013). "NGC 1252: a high altitude, metal poor open cluster remnant". Monthly Notices of the Royal Astronomical Society. 434 (1): 194–208. doi:10.1093/mnras/stt996. Archived from the original on 5 June 2018. Retrieved 11 October 2024.
- ^ "WEBDA page for open cluster NGC 1252". WEBDA. Archived from the original on 17 July 2024. Retrieved 17 July 2024.
- ^ de la Fuente Marcos, et al., table 4.
- ^ a b "NGC 1252 - Open Cluster in Horologium". The Sky Live. Apparent Size. Archived from the original on 3 July 2022. Retrieved 18 July 2024.
- ^ a b Bouchet, P.; Thé, P. S. (5 April 1983). "Notes on the open cluster NGC 1252 with the variable carbon star TW Horologii as a probable member" (PDF). The Astronomical Society of the Pacific. 95 (570): 474. Bibcode:1983PASP...95..474B. doi:10.1086/131195. Archived from the original on 4 May 2019. Retrieved 11 October 2024.
- ^ a b Pavani, D. B.; Bica, E.; Dutra, C. M.; Dottori, H.; Santiago, B. X.; Carranza, G.; Díaz, R. J. (15 August 2001). "Open clusters or their remnants: B and V photometry of NGC 1901 and NGC 1252" (PDF). Astronomy and Astrophysics. 374 (2): 554–563. arXiv:astro-ph/0106026. Bibcode:2001A&A...374..554P. doi:10.1051/0004-6361:20010741. Archived (PDF) from the original on 13 February 2024. Retrieved 11 October 2024.
- ^ "NGC 1252". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 21 July 2024.
- ^ Baumgardt, H. (3 September 1998). "The Nature of Some Doubtful Open Clusters as Revealed by Hipparcos". Astronomy & Astrophysics. 340. Springer Science+Business Media: 404. Bibcode:1998A&A...340..402B – via Astrophysics Data System.