Eta Scuti
Star in the constellation Scutum
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Eta Scuti, Latinized from η Scuti, is a single[10] star in the southern constellation of Scutum, near the constellation border with Aquila. Eta Scuti was a latter designation of 9 Aquilae before the official constellation borders were set in 1922.[11] It is visible to the naked eye as a faint, orange-hued star with an apparent visual magnitude of +4.83.[1] This object is located approximately 213 light-years from the Sun based on parallax, and is moving closer with a radial velocity of −92 km/s.[2]
 | |
| Observation data Epoch J2000 Equinox ICRS | |
|---|---|
| Constellation | Scutum[1] |
| Right ascension | 18h 57m 03.67027s[2] |
| Declination | −05° 50′ 46.7305″[2] |
| Apparent magnitude (V) | 4.83[1] |
| Characteristics | |
| Evolutionary stage | horizontal branch[3] |
| Spectral type | K1-III[4] |
| U−B color index | +1.02[5] |
| B−V color index | +1.08[5] |
| Astrometry | |
| Radial velocity (Rv) | −92.22±0.16[2] km/s |
| Proper motion (μ) | RA: +61.545[2] mas/yr Dec.: −41.429[2] mas/yr |
| Parallax (π) | 15.2960±0.1740 mas[2] |
| Distance | 213 ± 2 ly (65.4 ± 0.7 pc) |
| Absolute magnitude (MV) | 0.87[1] |
| Details | |
| Mass | 1.50[6] M☉ |
| Radius | 11.97+0.18 −0.13[2] R☉ |
| Luminosity | 62.7±0.8[2] L☉ |
| Surface gravity (log g) | 2.54[6] cgs |
| Temperature | 4,693+27 −266[2] K |
| Metallicity [Fe/H] | −0.03[6] dex |
| Rotational velocity (v sin i) | < 1.0[7] km/s |
| Age | 2.8[8] Gyr |
| Other designations | |
| η Sct, BD−06°4976, FK5 3821, GC 26013, HD 175751, HIP 93026, HR 7149, SAO 142838, GSC 05127-07358[9] | |
| Database references | |
| SIMBAD | data |
This is an aging giant star with a stellar classification of K1-III.[4] After exhausting the supply of hydrogen at its core, the star cooled and expanded until currently it has 12[2] times the girth of the Sun. It is a red clump giant, which indicates it is presently on the horizontal branch and is generating energy through core helium fusion.[3] The star is about 2.8 billion years old[8] with 1.5 times the mass of the Sun.[6] It is radiating 63[2] times the Sun's luminosity from its swollen photosphere at an effective temperature of 4,693 K.[2]