Observation data Epoch J2000.0 Equinox J2000.0 | |
---|---|
Constellation | Hercules |
Right ascension | 16h 28m 25.0031s [1] |
Declination | +36° 46′ 15.847″ [1] |
Apparent magnitude (V) | 13.83 [2] |
Characteristics | |
Evolutionary stage | white dwarf |
Spectral type | DZA5.5 [3] |
Astrometry | |
Proper motion (μ) |
RA: −494.230(15)
mas/
yr
[1] Dec.: 746.698(18) mas/ yr [1] |
Parallax (π) | 62.9109 ± 0.0143 mas [1] |
Distance | 51.84 ± 0.01
ly (15.895 ± 0.004 pc) |
Absolute magnitude (MV) | +13.01 [4] |
Details | |
Mass | 0.58±0.03 [5] M☉ |
Luminosity | 0.0007 [5] L☉ |
Surface gravity (log g) | 7.76 [6] cgs |
Temperature | 8,100 [7] K |
Age | 1.02 [6] Gyr |
Other designations | |
Database references | |
SIMBAD | data |
Ross 640 is a white dwarf star in the northern constellation of Hercules, positioned near the constellation border with Corona Borealis. With an apparent visual magnitude of 13.83, [2] it is too faint to be visible to the naked eye. Its trigonometric parallax from the Gaia mission is 62.9 ″, [1] corresponding to a distance of 52 light-years (15.9 parsecs).
This compact star has a stellar classification of DZA5.5, indicating a metal-rich atmosphere accompanied by weaker lines of hydrogen. [3] A detailed analysis of its spectrum revealed that Ross 640 is a relatively cool white dwarf with an effective temperature of approximately 8,100 K, which means that it has been in the white dwarf phase for slightly more than 1 billion years. [7] Ross 640 has a spectrum characterized by hydrogen Balmer lines in the visible and very strong ionized magnesium lines in the ultraviolet. [9] The presence of heavy elements in the photosphere of Ross 640 indicates that it recently accreted rocky debris from its planetary system.
Observation data Epoch J2000.0 Equinox J2000.0 | |
---|---|
Constellation | Hercules |
Right ascension | 16h 28m 25.0031s [1] |
Declination | +36° 46′ 15.847″ [1] |
Apparent magnitude (V) | 13.83 [2] |
Characteristics | |
Evolutionary stage | white dwarf |
Spectral type | DZA5.5 [3] |
Astrometry | |
Proper motion (μ) |
RA: −494.230(15)
mas/
yr
[1] Dec.: 746.698(18) mas/ yr [1] |
Parallax (π) | 62.9109 ± 0.0143 mas [1] |
Distance | 51.84 ± 0.01
ly (15.895 ± 0.004 pc) |
Absolute magnitude (MV) | +13.01 [4] |
Details | |
Mass | 0.58±0.03 [5] M☉ |
Luminosity | 0.0007 [5] L☉ |
Surface gravity (log g) | 7.76 [6] cgs |
Temperature | 8,100 [7] K |
Age | 1.02 [6] Gyr |
Other designations | |
Database references | |
SIMBAD | data |
Ross 640 is a white dwarf star in the northern constellation of Hercules, positioned near the constellation border with Corona Borealis. With an apparent visual magnitude of 13.83, [2] it is too faint to be visible to the naked eye. Its trigonometric parallax from the Gaia mission is 62.9 ″, [1] corresponding to a distance of 52 light-years (15.9 parsecs).
This compact star has a stellar classification of DZA5.5, indicating a metal-rich atmosphere accompanied by weaker lines of hydrogen. [3] A detailed analysis of its spectrum revealed that Ross 640 is a relatively cool white dwarf with an effective temperature of approximately 8,100 K, which means that it has been in the white dwarf phase for slightly more than 1 billion years. [7] Ross 640 has a spectrum characterized by hydrogen Balmer lines in the visible and very strong ionized magnesium lines in the ultraviolet. [9] The presence of heavy elements in the photosphere of Ross 640 indicates that it recently accreted rocky debris from its planetary system.