Observation data Epoch J2000.0 Equinox J2000.0 ( ICRS) | |
---|---|
Constellation | Draco |
Right ascension | 19h 15m 33.05868s [1] |
Declination | +73° 21′ 19.6769″ [1] |
Apparent magnitude (V) | 4.45 [2] |
Characteristics | |
Spectral type | K2 III: [3] |
U−B color index | +1.45 [2] |
B−V color index | +1.25 [2] |
Astrometry | |
Radial velocity (Rv) | −33.70 [3] km/s |
Proper motion (μ) |
RA: −115.29
[1]
mas/
yr Dec.: +103.23 [1] mas/ yr |
Parallax (π) | 22.28 ± 0.50 mas [1] |
Distance | 146 ± 3
ly (45 ± 1 pc) |
Absolute magnitude (MV) | +1.19 [4] |
Details | |
Mass | 1.25 [3] M☉ |
Luminosity | 48 [3] L☉ |
Surface gravity (log g) | 2.00 [5] cgs |
Temperature | 4,413±77 [3] K |
Metallicity [Fe/H] | 0.17±0.06 [6] dex |
Rotational velocity (v sin i) | 8 [7] km/s |
Age | 6.48 [3] Gyr |
Other designations | |
Database references | |
SIMBAD | data |
Tau Draconis, Latinized from τ Draconis, is an astrometric binary [9] star system in the northern circumpolar constellation of Draco. The star is faintly visible to the naked eye, having an apparent visual magnitude of 4.45. [2] Based upon an annual parallax shift of 22.28 mas as measured from Earth, [1] it is located around 146 light years from the Sun. Its proper motion is propelling it across the sky at the rate of 0.176 arc seconds per year. [10]
This is a K-type giant star with a stellar classification of K2 III:, [3] where the semi-colon indicates some uncertainty about its spectral value. It is considered metal-rich [6] star and is past the first dredge-up phase of its post- main sequence evolution, although it shows under-abundances of carbon and oxygen in its spectrum. [5] The star has 1.25 [3] times the mass of the Sun and is an estimated 6.48 [3] billion years old. It is radiating 48 [3] times the solar luminosity from its enlarged photosphere at an effective temperature of 4,413 K. [3]
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cite web}}
: CS1 maint: postscript (
link)
Observation data Epoch J2000.0 Equinox J2000.0 ( ICRS) | |
---|---|
Constellation | Draco |
Right ascension | 19h 15m 33.05868s [1] |
Declination | +73° 21′ 19.6769″ [1] |
Apparent magnitude (V) | 4.45 [2] |
Characteristics | |
Spectral type | K2 III: [3] |
U−B color index | +1.45 [2] |
B−V color index | +1.25 [2] |
Astrometry | |
Radial velocity (Rv) | −33.70 [3] km/s |
Proper motion (μ) |
RA: −115.29
[1]
mas/
yr Dec.: +103.23 [1] mas/ yr |
Parallax (π) | 22.28 ± 0.50 mas [1] |
Distance | 146 ± 3
ly (45 ± 1 pc) |
Absolute magnitude (MV) | +1.19 [4] |
Details | |
Mass | 1.25 [3] M☉ |
Luminosity | 48 [3] L☉ |
Surface gravity (log g) | 2.00 [5] cgs |
Temperature | 4,413±77 [3] K |
Metallicity [Fe/H] | 0.17±0.06 [6] dex |
Rotational velocity (v sin i) | 8 [7] km/s |
Age | 6.48 [3] Gyr |
Other designations | |
Database references | |
SIMBAD | data |
Tau Draconis, Latinized from τ Draconis, is an astrometric binary [9] star system in the northern circumpolar constellation of Draco. The star is faintly visible to the naked eye, having an apparent visual magnitude of 4.45. [2] Based upon an annual parallax shift of 22.28 mas as measured from Earth, [1] it is located around 146 light years from the Sun. Its proper motion is propelling it across the sky at the rate of 0.176 arc seconds per year. [10]
This is a K-type giant star with a stellar classification of K2 III:, [3] where the semi-colon indicates some uncertainty about its spectral value. It is considered metal-rich [6] star and is past the first dredge-up phase of its post- main sequence evolution, although it shows under-abundances of carbon and oxygen in its spectrum. [5] The star has 1.25 [3] times the mass of the Sun and is an estimated 6.48 [3] billion years old. It is radiating 48 [3] times the solar luminosity from its enlarged photosphere at an effective temperature of 4,413 K. [3]
{{
cite web}}
: CS1 maint: postscript (
link)