Groombridge 1618
10h 11m 22.1400s, +49° 27′ 15.2492″  Groombridge 1618 Location of Groombridge 1618 in the constellation Ursa Major | |
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Ursa Major |
| Right ascension | 10h 11m 22.13995s[1] |
| Declination | +49° 27′ 15.2510″[1] |
| Apparent magnitude (V) | +6.60[2] |
| Characteristics | |
| Spectral type | K7.5 Ve[3] |
| U−B color index | +1.27[2] |
| B−V color index | +1.34[2] |
| Variable type | BY Dra,[4] Flare star[5] |
| Absolute magnitude (MV) | 8.11[6] |
| Details | |
Gyr | |
| Database references | |
| SIMBAD | data |
Groombridge 1618 is a
Properties
This star was first identified as entry 1618 in the work A Catalog of Circumpolar Stars by
Groombridge 1618 has a
It is a
Search for planets
A search for excess infrared emission from this star by the Infrared Space Observatory came up negative, implying that Groombridge 1618 does not possess a nearby debris disk (such as Vega does).[16] However, observations using the Herschel Space Observatory showed a small excess suggesting a low-temperature debris disk. The data can be modeled by a ring of coarse, highly-reflective dust at a temperature below 22 K orbiting at least 51 AU from the host star.[8] If this star does have a companion, astrometric measurements appear to place an upper bound of 3–12 times the mass of Jupiter on such a hypothetical object (for orbital periods in the range of 5–50 years).[17]
Observations collated by Marcy & Benitz (1989),[18] tend towards a single notable object with periodicity of 122 days as a planetary object with minimum mass 4 times that of Jupiter. This candidate planet was never confirmed and the signal the authors had found could have been due to intrinsic stellar activity from the star's young age. If confirmed, the planet would be within the star's habitable zone.[note 1]
An examination of this system in 2010 using the MMT telescope fitted with adaptive optics failed to detect a planetary companion.[19]
The
The star is among five nearby K-type stars of a type in a 'sweet spot’ between Sun-analog stars and M stars for the likelihood of evolved life, per analysis of Giada Arney from NASA’s Goddard Space Flight Center.[21]
See also
- Stephen Groombridge
- List of nearest stars and brown dwarfs
Notes
- ^ a b [9] when used to calculate the stellar flux reaching the outer atmosphere of an Earth-like planet orbiting Groombridge 1618 at the Inner Habitable Zone edge - the Runaway Greenhouse limit gives a of 0.9397 or 93.97% the stellar flux reaching the top of Earth's atmosphere. By applying the previously calculated stellar flux and the known 15% luminosity of Groombridge 1618 into the equation, ,[9] the distance of the Inner HZ - Runaway Greenhouse limit from Groombridge 1618 can be calculated as .
References
- ^ S2CID 244398875. Gaia DR3 record for this source at VizieR.
- ^
- S2CID 117144290.
- ^ Bibcode:1992A&A...264L..31G.
- ^ Bibcode:1967lts..conf..160A.
- S2CID 118577511.
- ^ S2CID 10748478.
- ^ S2CID 14234038.
- ^ S2CID 76651902.
- ^ S2CID 15664454. See table 3.
- S2CID 119530297.
- Centre de Données astronomiques de Strasbourg. Retrieved 2013-08-01.
- Bibcode:1905Gmb...C......0D.
- Bibcode:1884DunOP...5..187B.
- Bibcode:1990A&A...238..221B.
- hdl:1887/7333.
- Bibcode:1978BAAS...10..630H.
- doi:10.1086/167812.
- S2CID 119199321.
- S2CID 44208180.
- ^
Bill Steigerwald (2019-03-07). ""Goldilocks" Stars May Be "Just Right" for Finding Habitable Worlds". NASA. Retrieved 2020-05-12.
'I find that certain nearby K stars like 61 Cyg A/B, Epsilon Indi, Groombridge 1618, and HD 156026 may be particularly good targets for future biosignature searches,' said Arney.
Notes
External links
- "Groombridge 1618". Sol Company. Retrieved 2007-06-24.
- "ARICNS 4C00785". Astronomisches Rechen-Institut. Archived from the original on 2007-06-10. Retrieved 2007-06-24.
