A broad-band optical light curve for AV Microscopii, plotted from data published by Tabur et al. (2009) [1] | |
Observation data Epoch J2000.0 Equinox J2000.0 ( ICRS) | |
---|---|
Constellation | Microscopium |
Right ascension | 20h 41m 24.66513s [2] |
Declination | −42° 08′ 01.6196″ [2] |
Apparent magnitude (V) | 6.28 [3] (6.25 – 6.35) [4] |
Characteristics | |
Spectral type | M4 III [5] |
B−V color index | 1.584±0.019 [3] |
Variable type | LC: [4] |
Astrometry | |
Radial velocity (Rv) | −22.9±0.9 [3] km/s |
Proper motion (μ) |
RA: +46.627
[2]
mas/
yr Dec.: −32.891 [2] mas/ yr |
Parallax (π) | 4.3815 ± 0.1715 mas [2] |
Distance | 740 ± 30
ly (228 ± 9 pc) |
Absolute magnitude (MV) | −1.40 [3] |
Details | |
Radius | 77.5+3.2 −16.4 [2] R☉ |
Luminosity | 849±38 [2] L☉ |
Temperature | 3,539+448 −70 [2] K |
Other designations | |
Database references | |
SIMBAD | data |
AV Microscopii is a variable star in the southern constellation of Microscopium. It is a dim, red-hued star near the lower limit of visibility to the naked eye with a baseline apparent visual magnitude of 6.28. [3] The star is located approximately 740 light years away from the Sun, based on parallax, [2] but is moving closer with a radial velocity of −23 km/s. [3] It is a member of the Milky Way's old disk population. [7]
Based upon a stellar classification of M4 III, [5] this is an aging red giant star, [5] having exhausted the supply of hydrogen at its core then expanded to around 78 [2] times the Sun's radius. Earlier it had been classed as M3 II, [8] with the luminosity class of a bright giant. Samus et al. (2017) have it tentatively classified as an irregular variable of subtype LC, suggesting this is a supergiant star. [4] It is a pulsating variable with multiple periods discovered, [1] ranging in apparent visual magnitude between 6.25 and 6.35. [4] [9] The star radiates 849 times the luminosity of the Sun from its enlarged photosphere at an effective temperature of 3,539 K. [2]
Period (days) | 22.3 | 23.3 | 30.3 | 31.0 | 32.3 | 45.0 | 110.7 |
Amplitude (mag.) | 0.038 | 0.050 | 0.017 | 0.027 | 0.019 | 0.025 | 0.018 |
A broad-band optical light curve for AV Microscopii, plotted from data published by Tabur et al. (2009) [1] | |
Observation data Epoch J2000.0 Equinox J2000.0 ( ICRS) | |
---|---|
Constellation | Microscopium |
Right ascension | 20h 41m 24.66513s [2] |
Declination | −42° 08′ 01.6196″ [2] |
Apparent magnitude (V) | 6.28 [3] (6.25 – 6.35) [4] |
Characteristics | |
Spectral type | M4 III [5] |
B−V color index | 1.584±0.019 [3] |
Variable type | LC: [4] |
Astrometry | |
Radial velocity (Rv) | −22.9±0.9 [3] km/s |
Proper motion (μ) |
RA: +46.627
[2]
mas/
yr Dec.: −32.891 [2] mas/ yr |
Parallax (π) | 4.3815 ± 0.1715 mas [2] |
Distance | 740 ± 30
ly (228 ± 9 pc) |
Absolute magnitude (MV) | −1.40 [3] |
Details | |
Radius | 77.5+3.2 −16.4 [2] R☉ |
Luminosity | 849±38 [2] L☉ |
Temperature | 3,539+448 −70 [2] K |
Other designations | |
Database references | |
SIMBAD | data |
AV Microscopii is a variable star in the southern constellation of Microscopium. It is a dim, red-hued star near the lower limit of visibility to the naked eye with a baseline apparent visual magnitude of 6.28. [3] The star is located approximately 740 light years away from the Sun, based on parallax, [2] but is moving closer with a radial velocity of −23 km/s. [3] It is a member of the Milky Way's old disk population. [7]
Based upon a stellar classification of M4 III, [5] this is an aging red giant star, [5] having exhausted the supply of hydrogen at its core then expanded to around 78 [2] times the Sun's radius. Earlier it had been classed as M3 II, [8] with the luminosity class of a bright giant. Samus et al. (2017) have it tentatively classified as an irregular variable of subtype LC, suggesting this is a supergiant star. [4] It is a pulsating variable with multiple periods discovered, [1] ranging in apparent visual magnitude between 6.25 and 6.35. [4] [9] The star radiates 849 times the luminosity of the Sun from its enlarged photosphere at an effective temperature of 3,539 K. [2]
Period (days) | 22.3 | 23.3 | 30.3 | 31.0 | 32.3 | 45.0 | 110.7 |
Amplitude (mag.) | 0.038 | 0.050 | 0.017 | 0.027 | 0.019 | 0.025 | 0.018 |