Platais 8

a Carinae Cluster
Observation data (J2000.0 epoch)
Right ascension09h 06m 52.3s[1]
Declination−58° 41′ 06″[1]
Distance440±1 ly (134.9±0.6 pc[1])
Apparent dimensions (V)3.45° × 3.45°[1]
Physical characteristics
Mass546+265
−178[2] M☉
Radius37.2 ± 4.9 ly (11.4 ± 1.5 pc)[2]
Estimated age60±15 Ma[3]
Other designationsPlatais 8, HIP 45080 Cluster, MWSC 1629
Associations
ConstellationCarina
See also: Open cluster, List of open clusters

Platais 8, also known as the a Carinae cluster or HIP 45080 Cluster is a small and faint open cluster located in the southern constellation Carina. It is estimated to be 440 light years distant based on parallax measurements.[1]

The cluster was first noticed by astronomer Imants Platais in 1998.[4] A 2005 paper suggests that Platais 8 might have formed near the area where the Scorpius-Centaurus association is located. [5] The SIMBAD database lists the cluster having 28,185 members[6] but the majority of the stars are field stars. In fact, there are only 32 members physically associated with the cluster.[1] The cluster has a combined mass of 546 M☉ and a radius of 37.2 light years. Platais 8 is rather young, with an age of only 60 million years.[3]

Members

These are the members of the cluster as identified by Canat-Gaudin et al. (2018)

Members of Cl Platais 8[7]
Name mv MK Type Dist. (ly) Notes
HD 76230 6.57 A0 V 410 Binary
HD 78802 7.33 A2 IV 467
HD 76413 7.48 A3 V 417
HD 80628 7.57 A0/1 V 442
HD 78761 7.68 A2 V 454
HD 78027 7.88 A1 V 444

The cluster also has one potential stream star located in Volans[1] and was considered to be a background object prior to 2020.

Name mv MK Type Dist. (ly) Notes
HD 71863 5.94 G8/K0 III 421 HR 3346

References

  1. ^ a b c d e f g Cantat-Gaudin, T.; Anders, F. (January 2020). "Clusters and mirages: cataloguing stellar aggregates in the Milky Way". Astronomy & Astrophysics. 633: A99. arXiv:1911.07075. Bibcode:2020A&A...633A..99C. doi:10.1051/0004-6361/201936691. ISSN 0004-6361.
  2. ^ a b Piskunov, A. E.; Schilbach, E.; Kharchenko, N. V.; Röser, S.; Scholz, R.-D. (26 March 2007). "Towards absolute scales for the radii and masses of open clusters". Astronomy & Astrophysics. 468 (1): 151–161. arXiv:astro-ph/0702517. Bibcode:2007A&A...468..151P. doi:10.1051/0004-6361:20077073. eISSN 1432-0746. ISSN 0004-6361.
  3. ^ a b Vande Putte, D.; Garnier, T. P.; Ferreras, I.; Mignani, R. P.; Cropper, Mark (6 September 2010). "A kinematic study of open clusters: implications for their origin". Monthly Notices of the Royal Astronomical Society. 407 (4): 2109–2121. arXiv:0912.0695. Bibcode:2010MNRAS.407.2109V. doi:10.1111/j.1365-2966.2010.17025.x. ISSN 0035-8711.
  4. ^ Platais, Imants; Kozhurina-Platais, Vera; van Leeuwen, Floor (November 1998). "A Search for Star Clusters from the ]Hipparcos Data". The Astronomical Journal. 116 (5): 2423–2430. Bibcode:1998AJ....116.2423P. doi:10.1086/300606. ISSN 0004-6256.
  5. ^ Piskunov, A. E.; Kharchenko, N. V.; Röser, S.; Schilbach, E.; Scholz, R.-D. (16 December 2005). "Revisiting the population of Galactic open clusters". Astronomy & Astrophysics. 445 (2): 545–565. arXiv:astro-ph/0508575. Bibcode:2006A&A...445..545P. doi:10.1051/0004-6361:20053764. eISSN 1432-0746. ISSN 0004-6361.
  6. ^ "Cl Platais 8". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 7 January 2021.
  7. ^ Cantat-Gaudin, T.; Jordi, C.; Vallenari, A.; Bragaglia, A.; Balaguer-Núñez, L.; Soubiran, C.; Bossini, D.; Moitinho, A.; Castro-Ginard, A.; Krone-Martins, A.; Casamiquela, L.; Sordo, R.; Carrera, R. (October 2018). "A Gaia DR2 view of the open cluster population in the Milky Way". Astronomy & Astrophysics. 618: A93. arXiv:1805.08726. Bibcode:2018A&A...618A..93C. doi:10.1051/0004-6361/201833476. ISSN 0004-6361.