Atlas (star)

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Atlas A
Observation data
Epoch J2000
Constellation
(pronunciation)
Pleiades
Right ascension 03h 49m 09.7s
Declination +24° 03′ 12″
Apparent magnitude (V) 3.62
Characteristics
Spectral type B8 III
U-B color index -0.36
B-V color index -0.09
Variable type Suspected
Astrometry
Radial velocity (Rv) +8.5 km/s
Proper motion (μ) RA: 17.77 mas/yr
Dec.: -44.7 mas/yr
Parallax (π) 8.57 ± 1.03 mas
Distance 381 ly (117 pc)
Absolute magnitude (MV) -2.55
Other designations
27 Tauri, HR 1178, BD +23°557, HD 23850, SAO 76228, FK5 142, GC 4586, ADS 2786, CCDM 03492+2403, NSV 01345, HIP 17847.

Atlas is a triple star system in the Pleiades open cluster (M45). It is also known as 27 Tauri.

The primary component, Atlas A, is a blue-white B-type giant with an apparent magnitude of +3.62. It is a spectroscopic binary whose components have magnitudes of +4.1 and +5.6. The binary makes one orbit every 1250 days. Atlas also has a dimmer magnitude +6.8 companion, Atlas B, at a separation of 0.4 arcseconds or at least 52 Astronomical Units away.

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