Kepler-33
Kepler-33 is a star in the constellation of Cygnus with a system of five known planets. Having just begun to evolve off from the main sequence,[6] its radius and mass are difficult to ascertain, although data available in 2020 shows its best-fit mass of 1.3M☉ and diameter of 1.6R☉ are compatible with a model of a subgiant star.[2]
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Cygnus |
| Right ascension | 19h 16m 18.6100s[1] |
| Declination | +46° 00′ 18.813″[1] |
| Apparent magnitude (V) | 13.988 |
| Characteristics | |
| Spectral type | G1IV |
| Astrometry | |
| Proper motion (μ) | RA: −1.107±0.031[1] mas/yr Dec.: −13.083±0.029[1] mas/yr |
| Parallax (π) | 0.7982 ± 0.0151[1] mas |
| Distance | 4,090 ± 80 ly (1,250 ± 20 pc) |
| Details | |
| Mass | 1.3 [2] M☉ |
| Radius | 1.6 [2] R☉ |
| Temperature | 5849 [3] K |
| Metallicity [Fe/H] | 0.12 [3] dex |
| Age | 4.8+1.4 −0.6 [4] Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
Planetary system
First detections of the four-body planetary system were reported in February 2011.[7] On January 26, 2012, a 5th planet around the star was confirmed.[6] However, unlike other planets confirmed via Kepler, their masses were initially not known, as Doppler Spectroscopy measurements were not done before the announcement. Judging by their radii, b may be a large Super-Earth or small Hot Neptune while the other four are all likely to be the latter.
Planets b and c may actually be in a 7:3 resonance, as there is a 0.05 day discrepancy; there is also a small 0.18 day discrepancy between a 5:3 resonance between planets c and d. The other planets do not seem to be in any resonances, though near resonances are 3d:2e and 4e:3f.
The planetary system in current configuration is highly susceptible to perturbations, therefore assuming stability, no additional giant planets can be located within 30 AU from the parent star.[8]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | — | 0.0677 ± 0.0014 | 5.66793 ± 0.00012 | — | — | 0.16 ± 0.02 RJ |
| c | — | 0.1189 ± 0.0025 | 13.1756 ± 0.00014 | — | — | 0.29 ± 0.027 RJ |
| d | 4.3+2.0 −2.0 M⊕ |
0.1626±0.0022 | 21.776 ± 0.00011 | — | — | 0.48 ± 0.04 RJ |
| e | 6.1+1.1 −1.0 M⊕ |
0.2092±0.0028 | 31.7844 ± 0.00039 | — | — | 0.36 ± 0.034 RJ |
| f | 10.6+1.6 −1.5 M⊕ |
0.2535 ± 0.0054 | 41.029 ± 0.00042 | — | — | 0.4 ± 0.037 RJ |
References
- Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
- Berger, Travis A.; Huber, Daniel; van Saders, Jennifer L.; Gaidos, Eric; Tayar, Jamie; Kraus, Adam L. (2020), The Gaia-Kepler Stellar Properties Catalog. I. Homogeneous Fundamental Properties for 186,301 Kepler Stars, arXiv:2001.07737
- Johnson, Michele (9 April 2015). "How many exoplanets has Kepler discovered?". nasa.gov.
- Chachan, Yayaati; Jontof-Hutter, Daniel; Knutson, Heather A.; Adams, Danica; Gao, Peter; Benneke, Björn; Berta-Thompson, Zachory; Dai, Fei; Deming, Drake; Ford, Eric; Lee, Eve J.; Libby-Roberts, Jessica E.; Madhusudhan, Nikku; Wakeford, Hannah R.; Wong, Ian (2020), "A Featureless Infrared Transmission Spectrum for the Super-Puff Planet Kepler-79d", The Astronomical Journal, 160 (5): 201, arXiv:2008.05480, doi:10.3847/1538-3881/abb23a, S2CID 221112629
- "Archived copy". Archived from the original on 2012-04-26. Retrieved 2012-02-01.CS1 maint: archived copy as title (link)
- Lissauer, Jack J.; Marcy, Geoffrey W.; Rowe, Jason F.; Bryson, Stephen T.; Adams, Elisabeth; Buchhave, Lars A.; Ciardi, David R.; Cochran, William D.; Fabrycky, Daniel C.; Ford, Eric B.; Fressin, Francois; Geary, John; Gilliland, Ronald L.; Holman, Matthew J.; Howell, Steve B.; Jenkins, Jon M.; Kinemuchi, Karen; Koch, David G.; Morehead, Robert C.; Ragozzine, Darin; Seader, Shawn E.; Tanenbaum, Peter G.; Torres, Guillermo; Twicken, Joseph D. (10 May 2012). "Almost All of Kepler's Multiple Planet Candidates are Planets". The Astrophysical Journal. 750 (2): 112. arXiv:1201.5424. Bibcode:2012ApJ...750..112L. doi:10.1088/0004-637X/750/2/112. S2CID 30549908.
- Ford, Eric B.; Rowe, Jason F.; Fabrycky, Daniel C.; Carter, Joshua A.; Holman, Matthew J.; Lissauer, Jack J.; Ragozzine, Darin; Steffen, Jason H.; Batalha, Natalie M.; Borucki, William J.; Bryson, Steve; Caldwell, Douglas A.; Dunham, Edward W.; Gautier, Thomas N.; Jenkins, Jon M.; Koch, David G.; Li, Jie; Lucas, Philip; Marcy, Geoffrey W.; McCauliff, Sean; Mullally, Fergal R.; Quintana, Elisa; Still, Martin; Tenenbaum, Peter; Thompson, Susan E.; Twicken, Joseph D. (2011), "Transit Timing Observations from Kepler : I. Statistical Analysis of the First Four Months", The Astrophysical Journal Supplement Series, 197: 2, arXiv:1102.0544, doi:10.1088/0067-0049/197/1/2, S2CID 118472942
- Becker, Juliette C.; Adams, Fred C. (2017), "Effects of Unseen Additional Planetary Perturbers on Compact Extrasolar Planetary Systems", Monthly Notices of the Royal Astronomical Society, 468: 549–563, arXiv:1702.07714, doi:10.1093/mnras/stx461, S2CID 119325005