Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Delphinus |
A | |
Right ascension | 20h 30m 17.9623s [1] |
Declination | +10° 53′ 45.335″ [1] |
Apparent magnitude (V) | 6.20±0.01 [2] |
B | |
Right ascension | 20h 30m 17.9505s [3] |
Declination | +10° 53′ 46.244″ [3] |
Apparent magnitude (V) | 8.00±0.01 [2] |
Characteristics | |
Spectral type | A1:III shell [4] |
U−B color index | −0.11 [5] |
B−V color index | −0.03 [5] |
Astrometry | |
Radial velocity (Rv) | −15.5 ± 2 [6] km/s |
Absolute magnitude (MV) | −0.69 [7] |
A | |
Proper motion (μ) |
RA: +19.320
mas/
yr
[1] Dec.: +4.645 mas/ yr [1] |
Parallax (π) | 4.6400 ± 0.0616 mas [1] |
Distance | 703 ± 9
ly (216 ± 3 pc) |
B | |
Proper motion (μ) |
RA: +19.545
[3]
mas/
yr Dec.: +4.710 [3] mas/ yr |
Parallax (π) | 4.1851 ± 0.1421 mas [3] |
Distance | 780 ± 30
ly (239 ± 8 pc) |
Details | |
A | |
Mass | 3.1±0.3 [8] M☉ |
Surface gravity (log g) | 3.66±0.77 [8] cgs |
Temperature | 10,651+932 −1156 [8] K |
Metallicity [Fe/H] | 0.00 [9] dex |
Rotational velocity (v sin i) | 217 [10] km/s |
Age | 246 [9] Myr |
B | |
Surface gravity (log g) | 4.14+0.19 −0.47 [8] cgs |
Rotational velocity (v sin i) | 370 [10] km/s |
Other designations | |
Database references | |
SIMBAD | data |
1 Delphini (1 Del) is the Flamsteed designation for a close binary star in the equatorial constellation Delphinus. With a combined apparent magnitude of 6.08, it is barely visible to the naked eye, even under ideal conditions. Parallax measurements put the components at a distance 703 and 780 light years respectively. However, its approaching the Solar System with a radial velocity of 15 km/s.
1 Del consists of three components. The brightest of them has a magnitude of 6.1; a companion located around 0.9 arcseconds from the primary has an apparent magnitude of 8.1; and a third star, located much farther away at around 17 arcseconds from component A, is the faintest with a magnitude of around 14 and is an unrelated background object. [11]
The entire system has a stellar classification of A1: III sh, indicating that it is a white giant + a shell star. However, there is some uncertainty about the temperature class. When resolved, the secondary has a class of B9. 1 Del A has 3 times the mass of the Sun and an effective temperature of 10,651 K, [8] giving it a bluish white glow. It is estimated to be almost 250 million years old and has a solar metallicity. [9] Both components spin rapidly, with projected rotational velocities of 217 and 370 km/s respectively. [10] As for the peculiarities, the shell star is a primary component; the spectrum of the secondary shows broad absorption lines. [10]
Due to the stability of the emission lines data from 1 Delphini has been used for developing models of shell stars and Be stars. [10]
Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Delphinus |
A | |
Right ascension | 20h 30m 17.9623s [1] |
Declination | +10° 53′ 45.335″ [1] |
Apparent magnitude (V) | 6.20±0.01 [2] |
B | |
Right ascension | 20h 30m 17.9505s [3] |
Declination | +10° 53′ 46.244″ [3] |
Apparent magnitude (V) | 8.00±0.01 [2] |
Characteristics | |
Spectral type | A1:III shell [4] |
U−B color index | −0.11 [5] |
B−V color index | −0.03 [5] |
Astrometry | |
Radial velocity (Rv) | −15.5 ± 2 [6] km/s |
Absolute magnitude (MV) | −0.69 [7] |
A | |
Proper motion (μ) |
RA: +19.320
mas/
yr
[1] Dec.: +4.645 mas/ yr [1] |
Parallax (π) | 4.6400 ± 0.0616 mas [1] |
Distance | 703 ± 9
ly (216 ± 3 pc) |
B | |
Proper motion (μ) |
RA: +19.545
[3]
mas/
yr Dec.: +4.710 [3] mas/ yr |
Parallax (π) | 4.1851 ± 0.1421 mas [3] |
Distance | 780 ± 30
ly (239 ± 8 pc) |
Details | |
A | |
Mass | 3.1±0.3 [8] M☉ |
Surface gravity (log g) | 3.66±0.77 [8] cgs |
Temperature | 10,651+932 −1156 [8] K |
Metallicity [Fe/H] | 0.00 [9] dex |
Rotational velocity (v sin i) | 217 [10] km/s |
Age | 246 [9] Myr |
B | |
Surface gravity (log g) | 4.14+0.19 −0.47 [8] cgs |
Rotational velocity (v sin i) | 370 [10] km/s |
Other designations | |
Database references | |
SIMBAD | data |
1 Delphini (1 Del) is the Flamsteed designation for a close binary star in the equatorial constellation Delphinus. With a combined apparent magnitude of 6.08, it is barely visible to the naked eye, even under ideal conditions. Parallax measurements put the components at a distance 703 and 780 light years respectively. However, its approaching the Solar System with a radial velocity of 15 km/s.
1 Del consists of three components. The brightest of them has a magnitude of 6.1; a companion located around 0.9 arcseconds from the primary has an apparent magnitude of 8.1; and a third star, located much farther away at around 17 arcseconds from component A, is the faintest with a magnitude of around 14 and is an unrelated background object. [11]
The entire system has a stellar classification of A1: III sh, indicating that it is a white giant + a shell star. However, there is some uncertainty about the temperature class. When resolved, the secondary has a class of B9. 1 Del A has 3 times the mass of the Sun and an effective temperature of 10,651 K, [8] giving it a bluish white glow. It is estimated to be almost 250 million years old and has a solar metallicity. [9] Both components spin rapidly, with projected rotational velocities of 217 and 370 km/s respectively. [10] As for the peculiarities, the shell star is a primary component; the spectrum of the secondary shows broad absorption lines. [10]
Due to the stability of the emission lines data from 1 Delphini has been used for developing models of shell stars and Be stars. [10]