NO Aurigae
 Location of NO Aurigae (circled) |
|
| Observation data Epoch J2000 Equinox J2000 |
|
|---|---|
| Constellation | Auriga |
| Right ascension | 05h 40m 42.05023s[1] |
| Declination | +31° 55′ 14.1920″[1] |
| Apparent magnitude (V) | 6.21[2] (6.06 - 6.44[3]) |
| Characteristics | |
| Spectral type | M2Iab[2] |
| U−B color index | +2.22[4] |
| B−V color index | +2.09[4] |
| R−I color index | +1.41[4] |
| Variable type | LC[3] |
| Astrometry | |
| Radial velocity (Rv) | 7.21 ± 0.45[5] km/s |
| Proper motion (μ) | RA: 0.13 ± 0.47[1] mas/yr Dec.: -3.65 ± 0.26[1] mas/yr |
| Parallax (π) | 1.68 ± 0.47 mas |
| Distance | 1,380[6] pc |
| Absolute magnitude (MV) | −5.88[2] |
| Details | |
| Mass | 4.93[7] M☉ |
| Radius | 630[2] R☉ |
| Luminosity | 75,000[2] L☉ |
| Surface gravity (log g) | 0.1[2] cgs |
| Temperature | 3,700[2] K |
| Other designations | |
| Database references | |
| SIMBAD | data |
| Data sources: | |
| Hipparcos Catalogue, CCDM (2002), Bright Star Catalogue (5th rev. ed.) |
|
NO Aurigae is a pulsating variable star in the constellation Auriga.
Variability
NO Aurigae is listed in the General Catalogue of Variable Stars as a slow irregular variable, indicating that no regularity could be found in the brightness variations. Other studies have suggested possible periods of 102.1, 173, and 226 days, and would classify it as a semiregular variable star.[8] The maximum visual magnitude range is 6.05 - 6.50.[8]
Properties
Most studies of NO Aurigae treat it as a supergiant member of the Auriga OB1 stellar association at about 1.4 kpc.[6][9] On this basis it has a luminosity around 75,000 L☉ and a radius of 630 R☉.
NO Aurigae is an MS star, intermediate between spectral type M and S. These are typically Asymptotic Giant Branch stars which can appear with supergiant spectra due to their large size and low mass.[10] Possible detection of Technetium in the spectrum is a symptom of the third dredge-up which occurs only in late AGB stars.[9] The revised Hipparcos parallax places it at 420 pc, around the third of the distance of Aur OB1, suggesting about a tenth of the derived luminosity for NO Aur. Calculations using this distance give luminosities of 15,600 L☉, 7,938 L☉,[11] or 6,968 L☉.[7]
References
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- ↑ 2.0 2.1 2.2 2.3 2.4 2.5 2.6 Lua error in package.lua at line 80: module 'strict' not found.
- ↑ 3.0 3.1 Lua error in package.lua at line 80: module 'strict' not found.
- ↑ 4.0 4.1 4.2 Lua error in package.lua at line 80: module 'strict' not found.
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- ↑ 6.0 6.1 Lua error in package.lua at line 80: module 'strict' not found.
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