Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Ara |
Right ascension | 16h 47m 08.92s [1] |
Declination | −45° 49′ 58.5″ [1] |
Apparent magnitude (V) | 16.7 |
Characteristics | |
Evolutionary stage | Red supergiant |
Spectral type | M1 [2] - M4Ia [3] |
Apparent magnitude (J) | 6.933 [4] |
Apparent magnitude (H) | 4.673 [4] |
Apparent magnitude (K) | 3.28 [4] |
Astrometry | |
Radial velocity (Rv) | −50.6±2.9 [1] km/s |
Proper motion (μ) |
RA: −2.029
[1]
mas/
yr Dec.: −4.248 [1] mas/ yr |
Parallax (π) | 0.0893 ± 0.1477 mas [1] |
Distance | 4,120+660 −330 [5] pc |
Details | |
Radius | 722±36 [2] R☉ |
Luminosity | 120,000±14,000 [2] L☉ |
Temperature | 3,600 [6] - 4,000 [2] K |
Other designations | |
Westerlund 1 BKS E,
2MASS J16470892-4549585, Gaia DR3 5940199877892579584 | |
Database references | |
SIMBAD | data |
Westerlund 1 W75 or Wd 1-75 is a red supergiant (RSG) located in the Westerlund 1 super star cluster. Its radius is calculated to be around 668 solar radii [6] (4.65 × 108 km, 3.10 au). This corresponds to a volume 298 million times bigger than the Sun. If placed at the center of the Solar System, Westerlund 1-75 would engulf the inner limits of the asteroid belt.
The star is classified as a luminous cool supergiant emitting most of its energy in the infrared spectrum. [7] It occupies the upper right corner of the Hertzsprung-Russell diagram. Using the effective temperature of 3,600 K, [6] the bolometric luminosity of 68,000 L☉ [6] and the solar effective temperature of 5,772 K, [8] the radius of Westerlund 1-75 can be calculated using the Stefan-Boltzmann law at 668 R☉. [a]
Like Westerlund 1-20, Westerlund 1 W26 and Westerlund 1-237, Westerlund 1-75 was observed to be a radio source, however it is weakest along the RSGs in its cluster and remains unresolved at any wavelength. [9]
Westerlund 1-75 is surrounded by extended nebula, although it appears less massive than nebulae around typical red supergiant stars. [10]
Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Ara |
Right ascension | 16h 47m 08.92s [1] |
Declination | −45° 49′ 58.5″ [1] |
Apparent magnitude (V) | 16.7 |
Characteristics | |
Evolutionary stage | Red supergiant |
Spectral type | M1 [2] - M4Ia [3] |
Apparent magnitude (J) | 6.933 [4] |
Apparent magnitude (H) | 4.673 [4] |
Apparent magnitude (K) | 3.28 [4] |
Astrometry | |
Radial velocity (Rv) | −50.6±2.9 [1] km/s |
Proper motion (μ) |
RA: −2.029
[1]
mas/
yr Dec.: −4.248 [1] mas/ yr |
Parallax (π) | 0.0893 ± 0.1477 mas [1] |
Distance | 4,120+660 −330 [5] pc |
Details | |
Radius | 722±36 [2] R☉ |
Luminosity | 120,000±14,000 [2] L☉ |
Temperature | 3,600 [6] - 4,000 [2] K |
Other designations | |
Westerlund 1 BKS E,
2MASS J16470892-4549585, Gaia DR3 5940199877892579584 | |
Database references | |
SIMBAD | data |
Westerlund 1 W75 or Wd 1-75 is a red supergiant (RSG) located in the Westerlund 1 super star cluster. Its radius is calculated to be around 668 solar radii [6] (4.65 × 108 km, 3.10 au). This corresponds to a volume 298 million times bigger than the Sun. If placed at the center of the Solar System, Westerlund 1-75 would engulf the inner limits of the asteroid belt.
The star is classified as a luminous cool supergiant emitting most of its energy in the infrared spectrum. [7] It occupies the upper right corner of the Hertzsprung-Russell diagram. Using the effective temperature of 3,600 K, [6] the bolometric luminosity of 68,000 L☉ [6] and the solar effective temperature of 5,772 K, [8] the radius of Westerlund 1-75 can be calculated using the Stefan-Boltzmann law at 668 R☉. [a]
Like Westerlund 1-20, Westerlund 1 W26 and Westerlund 1-237, Westerlund 1-75 was observed to be a radio source, however it is weakest along the RSGs in its cluster and remains unresolved at any wavelength. [9]
Westerlund 1-75 is surrounded by extended nebula, although it appears less massive than nebulae around typical red supergiant stars. [10]