42 Draconis b
| Discovery | |
|---|---|
| Discovered by | Doellinger et al. |
| Discovery site | TLS |
| Discovery date | March 20, 2009 |
| radial velocity | |
| Orbital characteristics | |
| Apastron | 1.64 AU (245,000,000 km) |
| Periastron | 0.74 AU (111,000,000 km) |
| 1.19 ± 0.01 AU (178,000,000 ± 1,500,000 km) | |
| Eccentricity | 0.38 ± 0.06 |
| 479.1 ± 6.2 d 1.312 ± 0.017 y | |
| 2452757.4 ± 3.7 | |
| 218.7 ± 10.6 | |
| Star | 42 Draconis |
| Physical characteristics | |
| Mass | ≥3.88±0.85 MJ |
42 Draconis b (abbreviated 42 Dra b), formally named Orbitar /ˈɔːrbɪtɑːr/, is a candidate extrasolar planet located approximately 315 light years from Earth in the constellation of Draco. It orbits the 5th magnitude K-type giant star 42 Draconis with a period of 479 days and 38% orbital eccentricity.[1] The planet was discovered using the radial velocity method on March 20, 2009.[1]
Following its discovery the planet was designated 42 Draconis b. In July 2014 the International Astronomical Union launched NameExoWorlds, a process for giving proper names to certain exoplanets and their host stars.[2] The process involved public nomination and voting for the new names.[3] In December 2015, the IAU announced the winning name was Orbitar for this planet.[4] The winning name was submitted by the Brevard Astronomical Society of Brevard County, Florida, United States.[5] Orbitar is a contrived word paying homage to the space launch and orbital operations of NASA.[6]
A 2021 study found that more recent radial velocity measurements of 42 Draconis were inconsistent with the proposed planetary orbit, casting serious doubt on 42 Draconis b's existence, but with a two-planet solution still being a possibility. The study suggests that the radial velocity signal is likely caused by a yet unknown stellar phenomenon, which might be common in giant stars.[7]
See also
[edit]References
[edit]- ^ a b Döllinger, M. P.; et al. (2009). "Planetary companion candidates around the K giant stars 42 Draconis and HD 139357". Astronomy and Astrophysics. 499 (3): 935–942. arXiv:0903.3593. Bibcode:2009A&A...499..935D. doi:10.1051/0004-6361/200810837. S2CID 15677079.
- ^ NameExoWorlds: An IAU Worldwide Contest to Name Exoplanets and their Host Stars. IAU.org. 9 July 2014
- ^ "NameExoWorlds". Archived from the original on 2015-08-15. Retrieved 2015-09-05.
- ^ Final Results of NameExoWorlds Public Vote Released, International Astronomical Union, 15 December 2015.
- ^ Website
- ^ "NameExoWorlds". Archived from the original on 2018-02-01. Retrieved 2015-12-18.
- ^ Döllinger, M. P.; Hartmann, M. (September 2021). "A Sanity Check for Planets around Evolved Stars". The Astrophysical Journal Supplement Series. 256 (1): 10. Bibcode:2021ApJS..256...10D. doi:10.3847/1538-4365/ac081a. S2CID 237369556.
External links
[edit]- Jean Schneider (2011). "Notes for Planet 42 Dra b". Extrasolar Planets Encyclopaedia. Retrieved 3 October 2011.
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