GSC 03549-02811 (sometimes referred to as Kepler-1, or either TrES-2A or TrES-2 parent star in reference to its exoplanet TrES-2b)[7] is a yellow main-sequence star similar to the Sun. This star is located approximately 704 light-years away in the constellation of Draco. The apparent magnitude of this star is 11.41, which means it is not visible to the naked eye but can be seen with a medium-sized amateur telescope on a clear dark night. The age of this star is about 5 billion years.[4]
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Draco |
| A | |
| Right ascension | 19h 07m 14.0376s[1] |
| Declination | +49° 18′ 59.091″[1] |
| Apparent magnitude (V) | 11.41 |
| B | |
| Right ascension | ~19h 07m 14s[2] |
| Declination | ~+49° 18′ 59″[2] |
| Characteristics | |
| A | |
| Spectral type | G0V[3] |
| Apparent magnitude (B) | ~12.030[4] |
| Apparent magnitude (V) | 11.411±0.005[4] |
| Apparent magnitude (I) | 11.07[2] |
| Apparent magnitude (Z) | 11.04[2] |
| Apparent magnitude (J) | 10.232±0.020[5] |
| Apparent magnitude (H) | 9.920±0.026[5] |
| Apparent magnitude (K) | 9.846±0.022[5] |
| Variable type | Planetary transit[3] |
| B | |
| Spectral type | K[2] |
| Apparent magnitude (I) | 14.73[2] |
| Apparent magnitude (Z) | 14.47[2] |
| Astrometry | |
| Proper motion (μ) | RA: 5.434(15) mas/yr[1] Dec.: 1.572(16) mas/yr[1] |
| Parallax (π) | 4.6308 ± 0.0116 mas[1] |
| Distance | 704 ± 2 ly (215.9 ± 0.5 pc) |
| Details | |
| A | |
| Mass | 1.05[2] M☉ |
| Radius | 1.000+0.036 −0.033[6] R☉ |
| Temperature | 5850±50[6] K |
| Metallicity | −0.15±0.1[6] |
| Age | 5.1+2.7 −2.3×109[6] years |
| B | |
| Mass | 0.67[2] M☉ |
| Other designations | |
| Database references | |
| SIMBAD | data |
Planetary system
In 2006 the exoplanet TrES-2b was discovered by the TrES program using the transit method. It is also within the field of view of the previously operational Kepler Mission planet-hunter spacecraft.[3] This system continues to be studied by other projects and the parameters are continuously improved.[6] The planet orbits the primary star.[2]
| Companion (in order from star) | Mass | Semimajor axis (AU) | Orbital period (days) | Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | 1.199(52) MJ | 0.03555(75) | 2.4706133738(187) | 0 (assumed) | 83.908(9)° | 1.189(25) RJ |
Though TrES-2b is currently the darkest known exoplanet, reflecting less than 1 percent of local sunlight, it shows a faint red glow. This is because its surface is 1,100 °C, it is so hot that it glows red. It is assumed to be tidally locked to its parent star.[9]
Binary star
In 2008 a study was undertaken of fourteen 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 15 K-type star separated by about 232 AU from the primary, appearing offset from the primary by about one arc second in the images. This discovery resulted in a significant recalculation of parameters for both the planet and the primary star.[2]
The Kepler mission
In March 2009 NASA launched the Kepler spacecraft. This spacecraft was a dedicated mission to discover extrasolar planets by the transit method from solar orbit. In April 2009 the project released the first light images from the spacecraft and TrES-2b was one of two objects highlighted in these images. Although TrES-2b is not the only known exoplanet in the field of view of this spacecraft it is the only one identified in the first-light images. This object is important for calibration and check-out.[10]
See also
References
External links
- "Host to 'Hot Jupiter' (labeled)". multimedia/images. NASA. 2009-04-16. Retrieved 2009-04-28.
- "TrES-2". Exoplanets. Archived from the original on 2009-11-25. Retrieved 2009-04-28.
- KIC 11446443