62 Sagittarii is a single,[10] variable star in the constellationofSagittarius. It has the Bayer designation c Sagittarii and the variable star designation V3872 Sagittarii, while 62 Sagittarii is its Flamsteed designation. This object forms the southwest corner of the asterism called the Terebellum. It is visible to the naked eye with an apparent visual magnitude that varies between 4.45 and 4.64,[2] and, at its peak, it is the brightest of the four stars in the Terebellum. 62 Sagittarii is the star in the Terebellum which is most distant from its centre; it is 1.72° from its northwest corner, 60 Sagittarii, and 1.37° from its southeast corner, 59 Sagittarii. This star is located approximately 450 light-years from the Sun based on parallax,[1] and is drifting further away with a radial velocity of +10 km/s.[5]
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Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
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Constellation | Sagittarius |
Right ascension | 20h02m 39.48097s[1] |
Declination | −27° 42′ 35.4443″[1] |
Apparent magnitude (V) | 4.45 to 4.64[2] |
Characteristics | |
Spectral type | M4.5III[3] |
U−B color index | +1.80[4] |
B−V color index | +1.65[4] |
R−I color index | +1.56[4] |
Variable type | LB[2] |
Astrometry | |
Radial velocity (Rv) | +9.9±0.8[5] km/s |
Proper motion (μ) | RA: +32.97[1] mas/yr Dec.: +14.00[1] mas/yr |
Parallax (π) | 7.27 ± 0.18 mas[1] |
Distance | 450 ± 10 ly (138 ± 3 pc) |
Absolute magnitude (MV) | −1.26[6] |
Details | |
Radius | 72+16 −6[7] R☉ |
Luminosity | 1,107±74[7] L☉ |
Temperature | 3,915+168 −380[7] K |
Rotational velocity (v sin i) | 1.5±1.5[8] km/s |
Other designations | |
c Sgr, 62 Sgr, V3872 Sagittarii, CD−28°16355, CPD−28°7105, FK5 753, GC 27763, HD 189763, HIP 98688, HR 7650, SAO 188844, PPM 270603[9] | |
Database references | |
SIMBAD | data |
This is an aging red giant with a stellar classification of M4.5III,[3] a star that has exhausted the supply of hydrogen at its core and expanded to around 72[7] times the Sun's radius. It is a slow irregular variable with multiple pulsation periods.[11] The star is radiating about 1,100[7] times the luminosity of the Sun from its swollen photosphere at an effective temperature of 3,915 K.[7]
Period (days) | 24.0 | 30.4 | 31.3 | 42.8 | 50.5 | 234.7 |
Amplitude (mag.) | 0.027 | 0.019 | 0.043 | 0.042 | 0.022 | 0.018 |