AS 314
Protoplanetary nebula in the constellation Scutum
From Wikipedia, the free encyclopedia
AS 314, also known as V452 Scuti, is a protoplanetary nebula[4] once believed to be a white hypergiant star or luminous blue variable located in the constellation of Scutum. It has an apparent magnitude of 9.85 and can be seen with small telescopes.
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Scutum |
| Right ascension | 18h 39m 26.10226s[2] |
| Declination | −13° 50′ 47.1597″[2] |
| Apparent magnitude (V) | 9.85[3] |
| Characteristics | |
| Spectral type | Protoplanetary nebula[4] |
| U−B color index | +0.12[3] |
| B−V color index | +0.89[3] |
| Variable type | α Cyg?[5] |
| Astrometry | |
| Radial velocity (Rv) | −77±8[2] km/s |
| Proper motion (μ) | RA: −4.416[2] mas/yr Dec.: −6.241[2] mas/yr |
| Parallax (π) | 0.5853±0.0141 mas[2] |
| Distance | 5,600 ± 100 ly (1,710 ± 40 pc) |
| Details | |
| Luminosity | 3,200[4] L☉ |
| Temperature | 10,200[6] K |
| Other designations | |
| V452 Sct, BD−13°5061, HIP 91477, 2MASS J18392610-1350470 | |
| Database references | |
| SIMBAD | data |
Characteristics
AS 314 was found to be a variable star in 1996, when the Hipparcos data was analyzed. For that reason it was given the variable star designation V452 Scuti, in 1999.[7]
AS 314 was poorly studied until the year 2000, when Miroshnichenko et al. incorrectly estimated a distance for this star of around 10 kiloparsecs (32,600 light years), a luminosity 160,000 times that of Sun (L☉), a radius 200 times the solar radius (R☉), and an initial mass of 20 solar masses (M☉). It was also estimated to be losing 2 × 10−5 M☉ each year (in other words, 1 M☉ every 50,000 years) through a very strong stellar wind.[8]
AS 314 has an infrared excess, suggesting that it is shrouded in a circumstellar envelope of dust.[8][9] However, it has not been classified as a bona fide luminous blue variable, but as a candidate.[10]
The Hipparcos parallax and proper motions are large and imply a much closer, and hence less luminous, star.[11] The Hipparcos measurement was later confirmed by the Gaia mission,[2] reclassifying AS 314 as post-AGB star.[4]