Rho1 Sagittarii
Star in the constellation Sagittarius
From Wikipedia, the free encyclopedia
Rho1 Sagittarii, Latinized from ρ1 Sagittarii, is a single,[13] variable star in the southern constellation of Sagittarius. It has a white hue and is visible to the naked eye with an apparent visual magnitude that fluctuates around 3.93.[2] The distance to this star is approximately 127 light years based on parallax,[1] and it is drifting further away with a radial velocity of +1.2 km/s.[5] It is positioned near the ecliptic and so it can be occulted by the Moon.[14]
 | |
| Observation data Epoch J2000 Equinox ICRS | |
|---|---|
| Constellation | Sagittarius |
| Right ascension | 19h 21m 40.35942s[1] |
| Declination | −17° 50′ 49.9168″[1] |
| Apparent magnitude (V) | 3.93[2] |
| Characteristics | |
| Spectral type | A9IV[3] |
| U−B color index | +0.14[2] |
| B−V color index | +0.22[2] |
| Variable type | δ Sct[4] |
| Astrometry | |
| Radial velocity (Rv) | +1.20[5] km/s |
| Proper motion (μ) | RA: −25.87[1] mas/yr Dec.: +21.46[1] mas/yr |
| Parallax (π) | 25.69±0.19 mas[1] |
| Distance | 127.0 ± 0.9 ly (38.9 ± 0.3 pc) |
| Absolute magnitude (MV) | 0.97[6] |
| Details | |
| Mass | 1.91[7] M☉ |
| Radius | 3.31+0.24 −0.26[8] R☉ |
| Luminosity | 30.7±0.8[8] L☉ |
| Surface gravity (log g) | 3.89[9] cgs |
| Temperature | 7,469+201 −261[8] K |
| Metallicity [Fe/H] | −0.02[10] dex |
| Rotational velocity (v sin i) | 68[11] km/s |
| Age | 893[9] Myr |
| Other designations | |
| ρ1 Sgr, 44 Sagittarii, BD−18°5322, GC 26694, GJ 4107, HD 181577, HIP 95168, HR 7340, SAO 162512, PPM 235882, GSC 06301-02457[12] | |
| Database references | |
| SIMBAD | data |
This object has a stellar classification of A9IV,[3] matching a subgiant star that is evolving away from the main sequence. It is a low amplitude Delta Scuti variable, ranging from 3.94 to 3.90 magnitude with a period of 0.05 days.[4] The star is 893[9] million years old and is spinning with a projected rotational velocity of 68 km/s.[11] It has 1.9[7] times the mass of the Sun and 3.3[8] times the Sun's radius. The star is radiating 31 times the luminosity of the Sun from its photosphere at an effective temperature of 7,469 K.[8]