Struve 2398
Coordinates: 
18h 42m 46.67934s, +59° 37′ 49.4724″
18h 42m 46.67934s, +59° 37′ 49.4724″  Struve 2398 Location of Struve 2398 in the constellation Draco | ||
| Observation data Epoch J2000 Equinox J2000 | ||
|---|---|---|
| Constellation | Draco | |
| Struve 2398 A | ||
| Right ascension | 18h 42m 46.70439s[1] | |
| Declination | +59° 37′ 49.4095″[1] | |
| Apparent magnitude (V) | 8.94[2] | |
| Struve 2398 B | ||
| Right ascension | 18h 42m 46.89467s[3] | |
| Declination | +59° 37′ 36.7212″[3] | |
| Apparent magnitude (V) | 9.70 | |
| Characteristics | ||
| Spectral type | M3 V + M3.5 V[4] | |
| U−B color index | 1.11/1.14 | |
| B−V color index | 1.53/1.59 | |
| Variable type | Flare star | |
| Details | ||
| Struve 2398 A | ||
Gyr | ||
Argument of periastron (ω)(secondary) | 203.8° | |
G 227-047 | ||
| Database references | ||
| SIMBAD | The system | |
| A | ||
| B | ||
Struve 2398 (Gliese 725) is a
closest to the Sun. Parallax measurements by the Gaia spacecraft give them an estimated distance of 11.5 light-years (3.5 parsecs
) away.
Both stars are small
The pair has a relatively high proper motion of 2.2 arc seconds per year. The system is on an orbit through the Milky Way that has an eccentricity of 0.05, carrying them as close as 8 kpc and as far as 9 kpc from the Galactic Center. The plane of their galactic orbit carries them as far as 463−489 pc away from the galactic plane.[11]
Planetary system
In 2016, a planet candidate on a 2.7-day orbit was proposed around Struve 2398 B, although the signal was found to be comparable with an instrumental noise floor.radial velocity method, without detection of the previous candidate.[13]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b (unconfirmed) | ≥15.7±5.7 M🜨 | 0.261+0.022 −0.028 |
91.29+0.31 −0.24 |
0.06+0.26 −0.06 |
— | — |
| c (unconfirmed) | ≥13.1+8.1 −6.4 M🜨 |
0.428+0.037 −0.045 |
192.4+2.2 −1.9 |
0.03+0.22 −0.03 |
— | — |
See also
References
- ^ S2CID 244398875. Gaia DR3 record for this source at VizieR.
- S2CID 41902340. See Table 3.
- ^ S2CID 244398875. Gaia DR3 record for this source at VizieR.
- ^ S2CID 19269312, 64.
- ^ S2CID 235435757. 40.
- ^ S2CID 118425326, 93.
- ^ Bibcode:1976A&AS...26..177B. Listed as ADS 11632.
- Bibcode:1991MmSAI..62..217P.
- doi:10.1086/176149.
- ^ "Struve 2398 AB". Retrieved 2010-10-22.
- Bibcode:1998RMxAA..34...37A.
- arXiv:1906.04644v1
External links
- SolStation entry
- http://www.daviddarling.info/encyclopedia/S/Struve2398.html
- http://www.richweb.f9.co.uk/astro/nearby_stars.htm
- http://jumk.de/astronomie/near-stars/struve-2398.shtml
- Struve 2398 in Dra
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