Trumpler 27 | |
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Observation data (J2000 epoch) | |
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 | |
True nature is unknown [2] | |
Other designations | C 1732-334 [1] |
Associations | |
Constellation | Scorpius |
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 |
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Trumpler 27-1 is a red supergiant star that is a member of the massive, possible open cluster Trumpler-27, where a blue giant star, a yellow supergiant star, and two Wolf–Rayet stars are also located.