GSC 02620-00648
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| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Hercules[1] |
| A[2] | |
| Right ascension | 17h 53m 13.0490s[3] |
| Declination | +37° 12′ 42.586″[3] |
| Apparent magnitude (V) | 11.592[4] |
| C[a] | |
| Right ascension | 17h 53m 13.0496s[5] |
| Declination | +37° 12′ 44.139″[5] |
| Apparent magnitude (V) | 13.85[2] |
| Characteristics | |
| Evolutionary stage | main sequence[3] |
| Spectral type | F8[2]/K or M[2] |
| Apparent magnitude (B) | 12.1120005±0.007[4] |
| Apparent magnitude (J) | 10.583±0.018[6] |
| Apparent magnitude (H) | 10.350±0.015[6] |
| Apparent magnitude (K) | 10.330±0.019[6] |
| Astrometry | |
| A | |
| Radial velocity (Rv) | −15.65±0.82[3] km/s |
| Proper motion (μ) | RA: −6.382 mas/yr[3] Dec.: −20.891 mas/yr[3] |
| Parallax (π) | 1.9686±0.0136 mas[3] |
| Distance | 1,660 ± 10 ly (508 ± 4 pc) |
| C | |
| Proper motion (μ) | RA: −6.307 mas/yr[5] Dec.: −20.387 mas/yr[5] |
| Parallax (π) | 1.9657±0.1076 mas[5] |
| Distance | 1,660 ± 90 ly (510 ± 30 pc) |
| Details[7] | |
| A | |
| Mass | 1.45±0.05 M☉ |
| Radius | 1.81±0.08 R☉ |
| Luminosity | 4.6[3] L☉ |
| Surface gravity (log g) | 4.09±0.03 cgs |
| Temperature | 6,295±65 K |
| Metallicity [Fe/H] | +0.28±0.09 dex |
| Rotational velocity (v sin i) | 8.5±0.5 km/s |
| Age | 2.2±0.4 Gyr |
| C | |
| Mass | 0.59[2] M☉ |
| Other designations | |
| TrES-4 Parent Star, TOI-2124, TIC 159742538, TYC 2620-648-1, GSC 02620-00648, 2MASS J17531304+3712426[8] | |
| Database references | |
| SIMBAD | A |
| C | |
| Exoplanet Archive | data |
GSC 02620-00648 is a binary star system located approximately 1,660 light-years away in the constellation Hercules. The brighter of the pair is a magnitude 12 star about 1.45 times as massive as the Sun. It hosts one known exoplanet, TrES-4b.[4]
The designation GSC 02620-00648 comes from the Guide Star Catalog.
The star is sometimes called TrES-4,[9] in reference to its planet discovered by the Trans-Atlantic Exoplanet Survey (TrES). The discovery paper[4] and the SIMBAD database[8] use this designation for the planet itself, but other sources call the star TrES-4[10] and the planet TrES-4b,[7] following the standard exoplanet naming convention.
Binary star
In 2008 a study was undertaken of 14 stars with exoplanets that were originally discovered using the transit method through relatively small telescopes. These systems were re-examined with the 2.2M reflector telescope at the Calar Alto Observatory in Spain. This star system, along with two others, was determined to be a previously unknown binary star system. The previously unknown secondary star is a dim magnitude 14 K or M-type star separated by about 755 AU from the primary, appearing offset from the primary by about one arc second in the images. This discovery resulted in a recalculation of parameters for both the planet and the primary star.[2]
Planetary system
In 2006, the Trans-Atlantic Exoplanet Survey discovered the exoplanet TrES-4b using the transit method.[4] This planet orbits the primary star.[2] The planet is a low-density hot Jupiter, with a larger size than Jupiter but a smaller mass, and an orbital period of only four days.[7]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | 0.498+0.033 −0.032 MJ |
0.05159+0.00059 −0.00061 |
3.55392771(47) | <0.015 | 83.07+0.51 −0.44° |
1.838+0.081 −0.090 RJ |
