Astronomy:Trumpler 27
Coordinates: 
17h 36m 20s, −33° 31′ 00″
| Trumpler 27 | |
|---|---|
 | |
| Observation data (J2000 epoch) | |
| Constellation | Scorpius |
| Right ascension | 17h 36m 20s[1] |
| Declination | −33° 31.0′[1] |
| Apparent magnitude (V) | 6.7[1] |
| Apparent dimensions (V) | 6′ × 6′[1] |
| Physical characteristics | |
| Notable features | True nature is unknown[2] |
| Other designations | C 1732-334[1] |
Trumpler 27 is a possible open cluster in the southern constellation Scorpius. If it exists, it is a few thousand light-years away from the Sun, with estimates ranging from 3,900 light-years (1,210 kiloparsecs)[3] to 6,800 light-years (2,100 kiloparsecs)[4] The name refers to Robert Julius Trumpler's catalog of open clusters, published in 1930.[5]
It was originally thought to be young open cluster in the outer edge of the Sagittarius Arm, still surrounded by interstellar matter.[5] The light from the stars is heavily extinguished and reddened by intervening interstellar dust.[4] The light coming from the stars is also significantly polarized.[6] However, a close study in 2012 could not confirm whether the stars truly form a cluster, or if they are a close alignment of bright stars.[2]
Several member stars have been studied in closer detail. Star #1 of Trumpler 27 is CD−33°12241, a red supergiant star with a spectral type of M0Ia. Stars #28 and #105 are Wolf-Rayet stars.[4][7] Star #27, a blue giant star with a spectral type of O8III((f)), may be one of the most luminous stars known, with a bolometric magnitude of −10.5.[7] Star #102 is known as V925 Scorpii or HD 159378,[8] and is a rare yellow supergiant star.[9]
| Star name | Temperature (K) |
Absolute magnitude |
Bolometric magnitude |
Mass (M☉) |
Spectral type |
|---|---|---|---|---|---|
| Trumpler 27-1 | 3,790 | -8.57 | -8.78 | 5.86 | M0Ia |
| Trumpler 27-28 (WR 95) | 44,000 | -5.25 | -8.3 | 10.7 | WC9d |
| Trumpler 27-105 (WR 98) | 40,000 | -6.62 | -10.1 | WN8/WC7 | |
| Trumpler 27-102 | 5,980 | -6.8 | -7 | G0Ia | |
| Trumpler 27-27 | 37,200 | -6.9 | -10.5 | 81 | O8III((f)) |
| Trumpler 27-23 | 27,500 | -7.5 | -10.2 | 64 | B0.5I |
| Trumpler 27-2 | 28,800 | -6.5 | -9.4 | 42 | B0Ia |
| Trumpler 27-46 | 11,200 | -8.7 | -9.3 | 35 | B8I |
| Trumpler 27-104 | 35,700 | -5.1 | -8.6 | 32 | O8.5III |
| Trumpler 27-43 | 11,200 | -8.2 | -8.9 | 29 | B8I |
| Trumpler 27-14 | 28,800 | -5.7 | -8.5 | 27 | B0Ib |
| Trumpler 27-16 | 27,500 | -5.7 | -8.5 | 26 | B0.5Ia |
| Trumpler 27-1a | 36,600 | -3.8 | -7.4 | 23 | |
| Trumpler 27-103 | 26,300 | -5.4 | -7.9 | 21 | B1I |
See also
References
- ↑ 1.0 1.1 1.2 1.3 1.4 "Cl Trumpler 27". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=Cl+Trumpler+27.
- ↑ 2.0 2.1 Perren, G.; Vázquez, R. A.; Carraro, G. (2012). "Photometric distances to young stars in the inner Galactic disk. II. The region towards the open cluster Trumpler 27 at L = 355°". Astronomy and Astrophysics 548: A125. doi:10.1051/0004-6361/201219653. Bibcode: 2012A&A...548A.125P.
- ↑ Morales, Esteban F. E.; Wyrowski, Friedrich; Schuller, Frederic; Menten, Karl M. (2013). "Stellar clusters in the inner Galaxy and their correlation with cold dust emission". Astronomy and Astrophysics 560: A76. doi:10.1051/0004-6361/201321626. Bibcode: 2013A&A...560A..76M.
- ↑ 4.0 4.1 4.2 Moffat, A. F. J.; Fitzgerald, M. P.; Jackson, P. D. (1977). "Trumpler 27: A heavily reddened young open cluster with blue and red supergiants". The Astrophysical Journal 215: 106. doi:10.1086/155338. Bibcode: 1977ApJ...215..106M.
- ↑ 5.0 5.1 The, P. S.; Stokes, N. (1970). "A study of the southern open clusters : TR 27, TR 28, NGC 6416, NGC 6425". Astronomy and Astrophysics 5: 298. Bibcode: 1970A&A.....5..298T.
- ↑ Feinstein, Carlos; Baume, Gustavo; Vazquez, Ruben; Niemela, Virpi; Cerruti, Miguel Angel (2000). "The Highly Polarized Open Cluster Trumpler 27". The Astronomical Journal 120 (4): 1906. doi:10.1086/301562. Bibcode: 2000AJ....120.1906F.
- ↑ 7.0 7.1 Cite error: Invalid
<ref>tag; no text was provided for refs namedMassey - ↑ "HD 159378". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=HD+159378.
- ↑ Bakker, R.; The, P. S. (1983). "An investigation of the heavily reddened young open cluster TR 27 on the Walraven photometric system". Astronomy and Astrophysics Supplement Series 52: 27. Bibcode: 1983A&AS...52...27B.
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