Struve 2398
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| Observation data Epoch J2000 Equinox J2000 |
|
|---|---|
| Constellation | Draco |
| Right ascension | 18h 42m 46.7/46.9s |
| Declination | +59° 37′ 49/36″ |
| Apparent magnitude (V) | 8.94/9.70 |
| Characteristics | |
| Spectral type | M3 V/M3.5 V |
| U−B color index | 1.11/1.14 |
| B−V color index | 1.53/1.59 |
| Variable type | Flare star |
| Astrometry | |
| Radial velocity (Rv) | –0.9 km/s |
| Proper motion (μ) | RA: –1327 mas/yr Dec.: +1802 mas/yr |
| Parallax (π) | 283.00 ± 1.69 mas |
| Distance | 11.52 ± 0.07 ly (3.53 ± 0.02 pc) |
| Absolute magnitude (MV) | 11.20/11.96 |
| Details | |
| Mass | 0.36 / 0.30 M☉ |
| Radius | 0.55 / 0.54 R☉ |
| Luminosity | 0.039 / 0.021 L☉ |
| Temperature | 3,500/3,000 K |
| Orbit[1] | |
| Companion | Struve 2398 B |
| Period (P) | 294.7 yr |
| Semimajor axis (a) | 10.50" |
| Eccentricity (e) | 0.70 |
| Inclination (i) | 52.5° |
| Longitude of the node (Ω) | 139.9° |
| Periastron epoch (T) | 1778.0 |
| Argument of periastron (ω) (secondary) |
203.8° |
| Database references | |
| SIMBAD | data |
| Other designations | |
| Database references | |
| SIMBAD | data |
Struve 2398 (also known as Gl 725 A and Gl 725 B[2]) is a binary star system in the constellation Draco. Both stars are red dwarfs and both display variability common to flare stars. The orbital period for the pair is about 295 years, with an average distance of about 56 astronomical units [3], and the eccentricity of the orbit is 0.70.
Struve 2398 is star number 2398 in the Struve Double Star Catalog of Baltic-German astronomer Friedrich Georg Wilhelm von Struve. The astronomer's surname, and hence the star identifier, is sometimes indicated by a Greek sigma, Σ.
Contents |
[edit] X-ray source
Gliese 725 A and B are sources of X-rays.[4]
[edit] See also
[edit] References
- ^ Baize, P. (October 1976). "Orbital elements of eighteen visual double stars". Astronomy and Astrophysics, Supplemental Series 26: 177–193. Bibcode 1976A&AS...26..177B. Listed as ADS 11632.
- ^ Mitchell Charity. What color are the stars?
- ^ "Struve 2398 AB". http://www.solstation.com/stars/st2398ab.htm. Retrieved 2010-10-22.
- ^ Schmitt JHMM, Fleming TA, Giampapa MS (September 1995). "The X-ray view of the low-mass stars in the solar neighborhood". Ap J. 450 (9): 392–400. Bibcode 1995ApJ...450..392S. doi:10.1086/176149.
[edit] 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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