Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Cassiopeia |
Right ascension | 23h 20m 44.5135s [1] |
Declination | +61° 11′ 40.531″ [1] |
Apparent magnitude (V) | 8.67 [2] |
Characteristics | |
Spectral type | O6.5(f)(n)p [3] |
U−B color index | −0.62 [2] |
B−V color index | +0.41 [2] |
Astrometry | |
Radial velocity (Rv) | −26 [4] km/s |
Proper motion (μ) |
RA: −2.662
[1]
mas/
yr Dec.: 0.388 [1] mas/ yr |
Parallax (π) | 0.3341 ± 0.0152 mas [1] |
Distance | 9,800 ± 400
ly (3,000 ± 100 pc) |
Absolute magnitude (MV) | −5.5 [5] |
Details [6] | |
Mass | 44 M☉ |
Radius | 15 R☉ |
Luminosity | 398,000 L☉ |
Temperature | 37,500 K |
Rotational velocity (v sin i) | 178 - 240 km/s |
Age | 2 [7] Myr |
Other designations | |
Database references | |
SIMBAD | data |
BD+60°2522 is a bright O-type star that has produced the Bubble Nebula ( NGC 7635) with its stellar wind. The exact classification of the star is uncertain, with a number of spectral peculiarities and inconsistencies between the appearance of the star itself and the effects on the nearby nebulosity, but it is undoubtedly a highly luminous hot massive star. [5] Direct spectroscopy yields a spectral class of O6.5 and an effective temperature around 37,500 K. It is a member of the Cassiopeia OB2 stellar association in the Perseus Arm [7] of the galaxy at about 8,500 light-years' distance. [8]
Although BD+60°2522 is around two million years old, the surrounding nebula is apparently only about 40,000 years old. The bubble is expected to be formed as a shock front where the stellar wind meets interstellar material at supersonic speeds. The wind from BD+60°2522 is travelling outwards at 1,800–2,500 km/s, causing the star to lose over a millionth of the mass of the Sun every year. [7]