Astronomy:Gliese 625
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Draco |
| Right ascension | 16h 25m 24.62304s[1] |
| Declination | +54° 18′ 14.7655″[1] |
| Apparent magnitude (V) | 10.13[2] |
| Characteristics | |
| Spectral type | M1.5V[3] |
| B−V color index | 1.591±0.027[2] |
| Astrometry | |
| Radial velocity (Rv) | −13.37±0.14[1] km/s |
| Proper motion (μ) | RA: 432.230(19)[1] mas/yr Dec.: −171.652(22)[1] mas/yr |
| Parallax (π) | 154.3503 ± 0.0161[1] mas |
| Distance | 21.131 ± 0.002 ly (6.4788 ± 0.0007 pc) |
| Absolute magnitude (MV) | 11.06[2] |
| Details | |
| Mass | 0.240±0.013[4] M☉ |
| Radius | 0.255±0.034[4] R☉ |
| Luminosity | 0.01482±0.00022[5] L☉ |
| Surface gravity (log g) | 4.94±0.06[6] cgs |
| Temperature | 3,557±9[7] K |
| Metallicity [Fe/H] | −0.401±0.005[7] dex |
| Rotation | 77.8±5.5 d[6] |
| Rotational velocity (v sin i) | 2.2±0.7[7] km/s |
| Other designations | |
| Database references | |
| SIMBAD | data |
GJ 625 (AC 54 1646-56) is a small red dwarf star with an exoplanetary companion in the northern constellation of Draco. The system is located at a distance of 21.1 light-years from the Sun based on parallax,[1] but is drifting closer with a radial velocity of −13 km/s.[7] It is too faint to be visible to the naked eye, having an apparent visual magnitude of 10.13[2] and an absolute magnitude of 11.06.[2]
This is an M-type main-sequence star with a stellar classification of M1.5V.[3] It is spinning slowly with a rotation period of roughly 78 days, and has a low magnetic activity level.[6] The star has about a quarter of the mass and size of the Sun,[4] and the metal content is 40% the abundances in the Sun's atmosphere. It is radiating just 1.5% of the luminosity of the Sun from its photosphere at an effective temperature of 3,557 K.[7]
Planetary system
On May 18, 2017, a planet was detected orbiting GJ 625 by the HARPS-N telescope. The planet, GJ 625 b, orbits near the inner edge of the optimistic circumstellar habitable zone of its star, and the discoverers speculate it may support liquid water, depending on atmospheric conditions.[6] Based on the habitable zone model of Kopparapu et al. 2013, the planet is not considered to be in the habitable zone as it would likely experience a runaway greenhouse effect, similar to Venus.[9][10][11][12]
Since the star is considered quiescent (having a low X-ray emission and flare rate), the radio emission from the system may be auroral in nature and coming from a short-period planet. Further observations will be needed to confirm this.[13]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | ≥2.82±0.51 M⊕ | 0.078361+0.000044 −0.000046 |
14.628+0.012 −0.013 |
0.13+0.12 −0.09 |
— | — |
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 Vallenari, A. et al. (2022). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy & Astrophysics. doi:10.1051/0004-6361/202243940 Gaia DR3 record for this source at VizieR.
- ↑ 2.0 2.1 2.2 2.3 2.4 Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters 38 (5): 331. doi:10.1134/S1063773712050015. Bibcode: 2012AstL...38..331A.
- ↑ 3.0 3.1 Alonso-Floriano, F. J. et al. (May 2015). "CARMENES input catalogue of M dwarfs. I. Low-resolution spectroscopy with CAFOS". Astronomy & Astrophysics 577: 19. doi:10.1051/0004-6361/201525803. A128. Bibcode: 2015A&A...577A.128A.
- ↑ 4.0 4.1 4.2 Khata, Dhrimadri et al. (April 2020). "Understanding the physical properties of young M dwarfs: NIR spectroscopic studies". Monthly Notices of the Royal Astronomical Society 493 (3): 4533–4550. doi:10.1093/mnras/staa427. Bibcode: 2020MNRAS.493.4533K.
- ↑ Schweitzer, A. et al. (May 2019). "The CARMENES search for exoplanets around M dwarfs. Different roads to radii and masses of the target stars". Astronomy & Astrophysics 625: 16. doi:10.1051/0004-6361/201834965. A68. Bibcode: 2019A&A...625A..68S. VizieR entry
- ↑ 6.0 6.1 6.2 6.3 6.4 Suárez Mascareño, A. et al. (2017). "HADES RV Programme with HARPS-N at TNG. V. A super-Earth on the inner edge of the habitable zone of the nearby M dwarf GJ 625". Astronomy and Astrophysics 605: A92. doi:10.1051/0004-6361/201730957. Bibcode: 2017A&A...605A..92S. https://www.aanda.org/articles/aa/full_html/2017/09/aa30957-17/aa30957-17.html.
- ↑ 7.0 7.1 7.2 7.3 7.4 Fouqué, Pascal et al. (April 2018). "SPIRou Input Catalogue: global properties of 440 M dwarfs observed with ESPaDOnS at CFHT". Monthly Notices of the Royal Astronomical Society 475 (2): 1960–1986. doi:10.1093/mnras/stx3246. Bibcode: 2018MNRAS.475.1960F.
- ↑ "G 202-48". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=G+202-48.
- ↑ Kopparapu, Ravi Kumar et al. (2013). "Habitable Zones Around Main-Sequence Stars: New Estimates". The Astrophysical Journal 765 (2): 131. doi:10.1088/0004-637X/765/2/131. Bibcode: 2013ApJ...765..131K.
- ↑ Kopparapu, Ravi Kumar. "Calculation of Habitable Zones". https://personal.ems.psu.edu/~ruk15/planets/.
- ↑ "GJ 625". http://hzgallery.org/3417_2.png.
- ↑ LePage, Andrew (22 May 2017). "Habitable Planet Reality Check: Is GJ 625b a Super-Earth or a Super-Venus?". https://www.drewexmachina.com/2017/05/22/habitable-planet-reality-check-is-gj-625b-a-super-earth-or-a-super-venus/.
- ↑ Pope, Benjamin J. S. et al. (September 2021). "The TESS View of LOFAR Radio-emitting Stars". The Astrophysical Journal Letters 919 (1): 8. doi:10.3847/2041-8213/ac230c. L10. Bibcode: 2021ApJ...919L..10P.
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