27 Aquilae
 Location of 27 Aquilae (circled) |
|
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) |
|
|---|---|
| Constellation | Aquila |
| Right ascension | 19h 20m 35.68321s[1] |
| Declination | −00° 53′ 31.8067″[1] |
| Apparent magnitude (V) | 5.49[2] |
| Characteristics | |
| Spectral type | B9 III[3] |
| U−B color index | −0.23[2] |
| B−V color index | −0.04[2] |
| Astrometry | |
| Radial velocity (Rv) | −27[4] km/s |
| Proper motion (μ) | RA: 5.42[1] mas/yr Dec.: 2.83[1] mas/yr |
| Parallax (π) | 7.45 ± 0.28[1] mas |
| Distance | 440 ± 20 ly (134 ± 5 pc) |
| Absolute bolometric magnitude (Mbol) |
2.04–2.27[5] |
| Details | |
| Surface gravity (log g) | 3.61 ± 0.50[6] cgs |
| Temperature | 11,500[6] K |
| Rotational velocity (v sin i) | 55[7] km/s |
| Other designations | |
27 Aquilae (abbreviated 27 Aql) is a star in the equatorial constellation of Aquila. 27 Aquilae is its Flamsteed designation though it also bears the Bayer designation d Aquilae. It has an apparent visual magnitude of 5.49,[2] which is faintly visible to the naked eye. Based upon parallax measurements made during the Hipparcos mission, this star is at a distance of 440 light-years (130 parsecs) from Earth, give or take a 20 light-year margin of error.[1] At this distance, the brightness of the star is diminished from extinction caused by interstellar gas and dust.[5]
The spectrum of 27 Aquilae fits a stellar classification of B9 III,[3] with the luminosity class of III typically indicating this is an evolved giant star. As it lies within the field of view of the CoRoT satellite,[6] close observation have been made of its luminosity. The star shows a multiperiodic variability with at least six pulsation frequencies discovered.[9] It has a high rate of rotation with a projected rotational velocity of 55 km/s.[7] The outer atmosphere is radiating energy into space at an effective temperature of around 11,500 K,[6] giving it the blue-white hue of a B-type star.
References
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- ↑ 2.0 2.1 2.2 2.3 Lua error in package.lua at line 80: module 'strict' not found.
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- ↑ 5.0 5.1 Lua error in package.lua at line 80: module 'strict' not found.
- ↑ 6.0 6.1 6.2 6.3 Lua error in package.lua at line 80: module 'strict' not found.
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