Delta Andromedae
Location of δ Andromedae (circled) | |
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Andromeda |
| Right ascension | 00h 39m 19.67518s[1] |
| Declination | +30° 51′ 39.6783″[1] |
| Apparent magnitude (V) | 3.28[2] |
| Characteristics | |
| Spectral type | K3 III[3] + K4 ± 2[4] |
| U−B color index | +1.48[2] |
| B−V color index | +1.28[2] |
| R−I color index | +0.66[5] |
| Astrometry | |
| Radial velocity (Rv) | −9.88±0.15[6] km/s |
| Proper motion (μ) | RA: +114.45[1] mas/yr Dec.: −84.02[1] mas/yr |
| Parallax (π) | 30.91±0.15 mas[1] |
| Distance | 105.5 ± 0.5 ly (32.4 ± 0.2 pc) |
| Absolute magnitude (MV) | +0.8[7] |
| Orbit[8] | |
| Period (P) | 15,000 d |
| Eccentricity (e) | 0.34±0.14 |
| Periastron epoch (T) | 2415568 JD |
| Argument of periastron (ω) (primary) | 356.1±5.2° |
| Semi-amplitude (K1) (primary) | 4.0±2.7 km/s |
| Details[4] | |
| δ And Aa | |
| Mass | ~1.3[9] M☉ |
| Radius | 13.6±0.3 R☉ |
| Luminosity | 68±4 L☉ |
| Surface gravity (log g) | 2.0±0.3[3] cgs |
| Temperature | 4,315±9 K |
| Metallicity [Fe/H] | 0.04 dex |
| Rotational velocity (v sin i) | 6.5[6] km/s |
| Age | 3.2 Gyr |
| δ And Ab | |
| Mass | 0.6–0.8 M☉ |
| Other designations | |
| δ And, Delta Andromedae, Delta And, 31 Andromedae, 31 And, NSV 15142, BD+30 91, FK5 20, HD 3627, HIP 3092, HR 165, SAO 54058, PPM 65514, WDS 00393+3052A[10][11] | |
| Database references | |
| SIMBAD | data |
Delta Andromedae is a triple star[12] system in the northern constellation of Andromeda. Its identifier is a Bayer designation that is Latinized from δ Andromedae, and abbreviated Delta And or δ And, respectively. The system is visible to the naked eye as a point of light with a combined apparent visual magnitude of 3.28.[2] Based upon parallax measurements, it is located at a distance of approximately 105.5 light-years (32.3 parsecs) from the Sun.[1] The system is drifting closer with a radial velocity of −10 km/s.[6]
In Chinese, 奎宿 (Kuí Sù), meaning Legs (asterism), refers to an asterism consisting of δ Andromedae, η Andromedae, 65 Piscium, ζ Andromedae, ι Piscium, ε Andromedae, π Andromedae, ν Andromedae, μ Andromedae, β Andromedae, σ Piscium, τ Piscium, 91 Piscium, υ Piscium, φ Piscium, χ Piscium and ψ1 Piscium. Consequently, the Chinese name for δ Andromedae itself is 奎宿五 (Kuí Sù wǔ, English: the Fifth Star of Legs.)[13] Apart from its Bayer designation, it was also given the title Delta by Elijah H. Burritt in his star atlas.[14]
This is a long-period spectroscopic binary with an orbital period of approximately 15,000 days (41 years). The primary of the spectroscopic binary, component Aa, has a stellar classification of K3 III, indicating that it is an aging giant star.[3][8] It most likely evolved from a F-type main sequence star after consuming the hydrogen at its core.[15] The secondary, component Ab, is a relatively faint K-type dwarf, which has been imaged using a stellar coronagraph. The pair have a physical separation of 11.55±0.13 AU.[4]
The system has two companions, the closest of which is an orbiting red dwarf of class M3 with a separation of at least 940 astronomical units.[16][17]
An excess of infrared emission from δ Andromedae suggested that it may be surrounded by a shell of dust.[3][18] In 2003 it was determined that this is more likely a circumstellar debris disk.[15]
References
[edit | edit source]- ^ a b c d e f Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ a b c d Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ a b c d Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value)..
- ^ a b c Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value)..
- ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value). ID V/50. Accessed on line August 28, 2008.
- ^ a b c Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ a b Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value)..
- ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value)..
- ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ (in Chinese) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 5 月 19 日 Archived 2016-03-03 at the Wayback Machine
- ^ Richard Hinckley Allen (1899) Star-names and Their Meanings, p. 38.
- ^ a b Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
External links
[edit | edit source]- The Constellation Andromeda: The Chained Maiden Archived 2021-02-13 at the Wayback Machine, web page, European Southern Observatory outreach.
- Image Delta Andromedae
