BD+60 1417b – Wikipedia

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BD+60 1417b is a confirmed exoplanet discovered in the year 2021 using the imaging method. BD+60 1417b is the only known exoplanet in the system BD+60 1417, around 45 parsecs from Earth.[2] BD+60 1417 is a young K0 star, while BD+60 1417 b has a late-L spectral type.[1][3] The planet might be the first discovery of a directly imaged exoplanet found by a citizen scientist. Discovery of exoplanets involving amateurs are usually transiting exoplanets and are rarely discovered with other methods. Another example of a non-transiting exoplanet discovery by an amateur is the microlensing exoplanet Kojima-1Lb.[4]


Previous direct imaging planet-searching surveys with Gemini, Keck and Palomar failed to detect an exoplanet around BD+60 1417. A co-moving source around the star was first spotted with the WiseView Tool by the Backyard Worlds citizen scientist Jörg Schümann. WiseView uses data from the Wide-Field Infrared Survey Explorer (WISE). Additional observations with optical spectroscopy of the star at the Lick Observatory and infrared spectroscopy at NASA IRTF confirmed the presence of a young star with a planetary-mass companion around BD+60 1417.[1]

BD+60 1417b is the second directly imaged exoplanet the WISE-telescope was able to discover, after COCONUTS-2b.

Host Star[edit]

The host star BD+60 1417 is a young K0 star with a mass of 1 M and a radius of 0.797 ±0.051 R.[1] It has a brightness of 9.37 magnitude.[5] The star shows typical signs of youth, such as x-ray detection with ROSAT[6] and lithium absorption lines. Its age is estimated at 50-150 Million years.[7] The star rotates with a period of 7.50 ± 0.86 days, which is seen due to evolving starspots in the TESS light curve.[1]

BD+60 1417 is the only main sequence star with about one solar mass that is orbited by a planetary-mass object at a separation larger than 1000 astronomical units. All other systems with a separation >1000 au have a primary with <0.5 solar masses or are the stellar remnant WD0806.[1]

The Planet[edit]

The infrared spectrum of the planet shows a red L8γ-type object with water vapor, carbon monoxide, iron(I) hydride and potassium iodide in its atmosphere. In the near-infrared it is one of the reddest substellar objects discovered to date with

JKs=2.72{displaystyle J-Ks=2.72}

mag. The spectrum of the exoplanet closely resembles objects with a suspected low surface gravity. A low surface gravity is a sign of youth for substellar objects. The researchers also found similarities with an archived SINFONI spectrum of the exoplanet 2M1207b and spectra of the HR 8799 exoplanets.[1] The planet has an orbital period of about 95,000 years.[8]

BD+60 1417b has a large separation of 1662 astronomical units from its host star. If this exoplanet has formed in this wide orbit, it is likely to have formed similar to isolated brown dwarfs. It could also have formed in a closer orbit around the star via core accretion or disk instability and was later dynamically disturbed into a higher orbit, for example by a planet-planet fly-by.[1]

Status as an exoplanet[edit]

According to the NASA Exoplanet Archive BD+60 1417b is an exoplanet[9] and it falls within their definition: An object with a minimum mass lower than 30 Jupiter masses and a not free-floating object with sufficient follow-up.[10] The official working definition by the International Astronomical Union allows only exoplanets with a maximum mass of 13 Jupiter masses[11] and according to current knowledge BD+60 1417b could be more massive than this limit.

See also[edit]


  1. ^ a b c d e f g h i j k Faherty, Jacqueline K.; Gagné, Jonathan; Popinchalk, Mark; Vos, Johanna M.; Burgasser, Adam J.; Schümann, Jörg; Schneider, Adam C.; Kirkpatrick, J. Davy; Meisner, Aaron M.; Kuchner, Marc J.; Bardalez Gagliuffi, Daniella C.; Marocco, Federico; Caselden, Dan; Gonzales, Eileen C.; Rothermich, Austin; Casewell, Sarah L.; Debes, John H.; Aganze, Christian; Ayala, Andrew; Hsu, Chih-Chun; Cooper, William J.; Smart, R. L.; Gerasimov, Roman; Theissen, Christopher A.; The Backyard Worlds: Planet 9 Collaboration (2021). “A Wide Planetary Mass Companion Discovered through the Citizen Science Project Backyard Worlds: Planet 9”. The Astrophysical Journal. 923 (1): 48. arXiv:2112.04678. Bibcode:2021ApJ…923…48F. doi:10.3847/1538-4357/ac2499. S2CID 245005964.
  2. ^ “The Extrasolar Planet Encyclopaedia — BD+60 1417 b”. Retrieved 2021-12-13.
  3. ^ “A Wide Planetary Mass Companion Discovered Through the Citizen Science Project Backyard Worlds: Planet 9”. Retrieved 2021-12-13.
  4. ^ Fukui, A.; Suzuki, D.; Koshimoto, N.; Bachelet, E.; Vanmunster, T.; Storey, D.; Maehara, H.; Yanagisawa, K.; Yamada, T.; Yonehara, A.; Hirano, T. (2019-11-01). “Kojima-1Lb Is a Mildly Cold Neptune around the Brightest Microlensing Host Star”. The Astronomical Journal. 158 (5): 206. arXiv:1909.11802. Bibcode:2019AJ….158..206F. doi:10.3847/1538-3881/ab487f. ISSN 0004-6256. S2CID 202888719.
  5. ^ “SIMBAD basic query result”. Retrieved 2022-08-11.
  6. ^ Voges, W.; Aschenbach, B.; Boller, T.; Brauninger, H.; Briel, U.; Burkert, W.; Dennerl, K.; Englhauser, J.; Gruber, R.; Haberl, F.; Hartner, G. (2000-05-01). “Rosat All-Sky Survey Faint Source Catalogue”. International Astronomical Union Circular (7432): 3. Bibcode:2000IAUC.7432….3V. ISSN 0081-0304.
  7. ^ Wichmann, R.; Schmitt, J. H. M. M.; Hubrig, S. (2003-03-01). “Nearby young stars”. Astronomy and Astrophysics. 399 (3): 983–994. Bibcode:2003A&A…399..983W. doi:10.1051/0004-6361:20021867. ISSN 0004-6361. S2CID 122229912.
  8. ^ Díez, Álvaro; Panfil, Miłosz; Czernia, Dominik. “Orbital Period Calculator | Binary System”. Retrieved 2022-08-14. Used inclination correction (1.26×1662 au)
  9. ^ “BD+60 1417 | NASA Exoplanet Archive”. Retrieved 2022-08-10.
  10. ^ “Exoplanet Criteria for Inclusion in the Exoplanet Archive”. Retrieved 2022-08-10.
  11. ^ “International Astronomical Union | IAU”. Retrieved 2022-08-10.

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