NGC 1252
NGC 1252 from 2MASS
NGC 1252 from 2MASS
Observation data (J2000 epoch)
Right ascension03h 10m 47s[1]
Declination−57° 45′ 18″[1]
Distance2,100 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[5]
Estimated age3000.00±1000.00 Ma[6]
Other designationsESO 116-11[7]
Associations
ConstellationHorologium[4]
GalaxyMilky Way
See also: Open cluster, List of open clusters

NGC 1252 is a possible open cluster or open cluster remnant in the constellation of Horologium. Discovered in 1834 by Sir John Herschel, it was included in the New General Catalogue as a single star surrounded by 18 to 20 other stars. In 1973, the Revised New General Catalogue included it as an unverified southern object.[8] Since then, it has been classified as an open cluster, open cluster remnant, asterism (astronomy), or non-existent. Its membership, location, and proper motion are also uncertain. This uncertainty is due to its proximity to the Tucana-Horologium association and Hyades Stream.[9]

History

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Initially discovered in 1834 by John Herschel, NGC 1252 was included in his paper "Results of Astronomical Observations Made During the Years 1834, 5, 6, 7, 8, at the Cape of Good Hope" as h 2515.[10] It was subsequently included in Herschel's expansion of his father's Catalogue of Nebulae and Clusters of Stars as h 663.[11] John Louis Emil Dreyer included it in the New General Catalogue of Nebulae and Clusters of Stars in 1888.[12]

NGC 1252 was largely unobserved until 1973,[9] when Jack W. Sulentic and William G. Tifft published the Revised New General Catalogue. Although Sulentic and Tifft found NGC 1252 to be an unverified southern object, they also found that most of the approximately 90 objects labeled as such likely exist.[13]

In 1983, Patrice Bouchet and P. S. Thé made the first detailed study of NGC 1252.[9] They found that it is a possible open cluster that, if existent, possesses a main sequence and a giant branch, and consists of 14 probable members, including TW Horologii.[14] Olin J. Eggen published a rebuttal to Bouchet and Thé (1983) in 1984, finding that NGC 1252 is probably not an open cluster and that TW Horologii is part of the Hyades Supercluster.[15]

In 1998, Holger Baumgardt determined that NGC 1252 does not exist, using data from the Hipparcos and ACT catalogues.[16]

In 2000, a team at the Federal University of Rio Grande do Sul included NGC 1252 in a survey of late-stage open clusters. NGC 1252 was found to be a Possible Open Cluster Remnant (POCR) at right ascension 3h 10m 49s, declination −57° 46′ 00″, major and minor diameters of 14′ and 11′ respectively, and a reddening value of 0.02. It was also determined to have 8 member stars, only one of which (No. 1, HD 20059) was included in Bouchet and Thé's study.[17] In 2004, Y. Xin and Li-Cai Deng found NGC 1252 to consist of a single blue straggler and seven stars within two magnitudes of the cluster's turnoff point, based on data from J. Ahumada and E. Lapasset (1995).[18]

In July 2003, the second US Naval Observatory (USNO) CCD Astrograph Catalog was released, containing positions and proper motions of 48,330,571 sources, primarily stars, including NGC 1252.[19] These data were subsequently used by Dias et al. (2006) to determine the proper motions of 630 open clusters. NGC 1252 was found to have proper motion components of μα cos δ 14.28 and μδ 9.07,[note 3] with an error of 1.41. It was also found to have a membership of 25 stars and radius of 15 arcminutes.[20]

Location and proper motion

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Membership

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TW Horologii

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Classification

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Notes

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  1. ^ Estimates range from ~1,500 ly (470 pc) (Bouchet and Thé (1983)) to ~2,600 ly (790 pc) (Pavani and Bica (2007)); see text for a more complete discussion.
  2. ^ Average of the 13 stars that de la Fuente Marcos et al. include as members.
  3. ^ Proper motion is given in two parts, in the direction of right ascension (μα) and direction of declination (μδ).

References

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  1. ^ a b de la Fuente Marcos, R; de la Fuente Marcos, C.; Bidin, C. Moni; Carraro, G.; Costa, E. (2013). "NGC 1252: a high altitude, metal poor open cluster remnant". Monthly Notices of the Royal Astronomical Society. 434 (1). Oxford University Press. Proper Motions: Candidate Member Selection. arXiv:1306.1643. Bibcode:2013MNRAS.434..194D. doi:10.1093/mnras/stt996. Archived from the original on 5 June 2018. Retrieved 18 August 2024.{{cite journal}}: CS1 maint: unflagged free DOI (link)
  2. ^ "WEBDA page for open cluster NGC 1252". WEBDA. Archived from the original on 17 July 2024. Retrieved 17 July 2024.
  3. ^ de la Fuente Marcos, et al., table 4.
  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.
  5. ^ Bouchet, P.; Thé, P. S. (1983). "Notes on the Open Cluster NGC 1252 with the Variable Carbon Star TW Horologii as a Probable Member" (PDF). Publications of the Astronomical Society of the Pacific. 95. IOP Publishing: 477. doi:10.1086/131195. Archived from the original on 4 May 2019. Retrieved 6 August 2024.
  6. ^ Pavani, D. B.; Bica, E.; Dutra, C. M.; et al. (2001). "Open clusters or their remnants: B and V photometry of NGC 1901 and NGC 1252" (PDF). Astronomy and Astrophysics. 374. EDP Sciences: 554. 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 21 July 2024.
  7. ^ "NGC 1252". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 21 July 2024.
  8. ^ Sulentic, Jack W.; Tifft, William G. (1973). The Revised New General Catalogue of Nonstellar Astronomical Objects. University of Arizona Press. pp. ix, 58. Bibcode:1979rngc.book.....S. ISBN 9780816504213.
  9. ^ a b c de la Fuente Marcos, et al. "NGC 1252: A controversial object."
  10. ^ Herschel, John F. W. (1847). Results of Astronomical Observations Made During the Years 1834, 5, 6, 7, 8, at the Cape of Good Hope. Smith, Elder & Co. p. 60. Bibcode:1847raom.book.....H. ISBN 9781018783345. LCCN 07005139. Retrieved 25 July 2024.
  11. ^ Herschel, John Frederick William (1864). "Catalogue of Nebulae and Clusters of Stars". Philosophical Transactions of the Royal Society. 154 (1). The Royal Society: 58. Bibcode:1864RSPT..154....1H. JSTOR stable/108864. Retrieved 25 July 2024 – via JSTOR.
  12. ^ Dreyer, J. L. E. (1888). "A New General Catalogue of Nebulæ and Clusters of Stars, being the Catalogue of the late Sir John F. W. Herschel, Bart, revised, corrected, and enlarged" (PDF). Memoirs of the Royal Astronomical Society. 49: 45. Bibcode:1888MmRAS..49....1D. Archived from the original on 19 November 2022. Retrieved 3 August 2024 – via Astrophysics Data System.
  13. ^ Sulentic, Jack W.; Tifft, William G. (1973). The Revised New General Catalogue of Nonstellar Astronomical Objects. University of Arizona Press. p. xviii. Bibcode:1979rngc.book.....S. ISBN 9780816504213. Southern clusters and nebulae are well catalogued; thus, little difficulty was encountered in obtaining basic data for these objects. Few literature sources, however, exist for far southern NGC galaxies. The primary source is the 1956 survey by de Vaucouleurs. After employing available literature sources, there remained about 150 objects for which no reference could be found in the literature except in the original NGC. One-third of these objects were identified with the assistance of W. Stonaker, who obtained a series of plates using the 24-inch Michigan Curtis-Schmidt at Cerro Tololo Inter-American Observatory. On these plates, 48 of 50 possible objects were identified. An additional 10 objects were identified with the aid of plates available at the Cordoba and Radcliffe observatories. From this study it is apparent that most of the approximately 90 remaining unverified objects do in fact exist and will lie within 5' of their NGC positions. These objects are listed with a 0 in the type column.
  14. ^ Bouchet and Thé (1983), pp. 476-478
  15. ^ Eggen, O. J. (1984). "TW Horologii and NGC 1252. A Rebuttal" (PDF). Publications of the Astronomical Society of the Pacific. 96. IOP Publishing: 71. doi:10.1086/131303. Archived from the original on 27 July 2018. Retrieved 6 August 2024.
  16. ^ Baumgardt, H. (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.
  17. ^ Bica, E.; Santiago, B. X.; Dutra, C. M.; et al. (2001). "Dissolving Star Cluster Candidates" (PDF). Astronomy & Astrophysics. 366. EDP Sciences: 829. arXiv:astro-ph/0011280. Bibcode:2001A&A...366..827B. doi:10.1051/0004-6361:20000248. Archived (PDF) from the original on 20 September 2022. Retrieved 14 August 2024.
  18. ^ Xin, Y.; Deng, L (15 September 2004). "Blue Stragglers in Galactic Open Clusters and Integrated Spectral Energy Distributions" (PDF). The Astrophysical Journal. 619 (2). IOP Publishing: 825, 832. arXiv:astro-ph/0410325. Bibcode:2005ApJ...619..824X. doi:10.1086/426681. Archived from the original on 12 May 2023. Retrieved 22 September 2024.
  19. ^ Zacharias, N.; Urban, S. E.; Zacharias, M. I.; Wycoff, G. L.; Hall, D. M.; Monet, D. G.; Rafferty, T. J. (17 February 2004). "The Second US Naval Observatory CCD Astrograph Catalog (UCAC2)" (PDF). The Astronomical Journal (127). IOP Publishing. Abstract. arXiv:astro-ph/0403060. Bibcode:2004AJ....127.3043Z. doi:10.1086/386353. Archived from the original on 23 January 2023. Retrieved 26 October 2024.
  20. ^ Dias, W. S.; Assafin, D.; Flório, V.; Alessi, B. S.; Líbero, V. (16 September 2005). "Proper motion determination of open clusters based on the UCAC2 catalogue" (PDF). Astronomy & Astrophysics. 446. EDP Sciences. Table 1. Bibcode:2006A&A...446..949D. doi:10.1051/0004-6361:20052741. Archived (PDF) from the original on 30 November 2023. Retrieved 26 October 2024.
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Table 1 for Dias, Assafin, and Alessi et al. (2005).