CVSO 30 (PTFO 8-8695) is a suspected binary T Tauri star, located in constellation Orion at 1200 light years from Earth with one candidate planet called CVSO 30 c. The candidate planet is a gas giant. The star is named after the CIDA Variability Survey of Orion (CVSO)[4] and the Palomar Transient Factory (PTF) and is within the 25 Ori group.[5]

CVSO 30

VLT image of CVSO 30 and its planet, CVSO 30 c
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Orion
Right ascension 05h 25m 07.556s[1]
Declination +01° 34′ 24.349″[1]
Apparent magnitude (V) +16.26[2]
Characteristics
Spectral type M3[2]
Variable type T Tau[2]
Astrometry
Proper motion (μ) RA: +1.73[1] mas/yr
Dec.: +0.13[1] mas/yr
Parallax (π)2.861 ± 0.075[1] mas
Distance1140 ± 30 ly ly
(349.5 ± 9.2[1] pc)
Details
Mass0.39 ± 0.05[2] M
Radius1.39[2] R
Temperature3470[2] K
Age2.65[3] Myr
Other designations
2MASS J05250755+0134243, PTFO 8-8695
Database references
SIMBADdata

Planetary system

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The CVSO 30 planetary system
Companion
(in order from star)
Mass Semimajor axis
(AU)
Orbital period
(years)
Eccentricity Inclination Radius
c (unconfirmed) 4.7 MJ 660 27000

CVSO 30 may have one planet called CVSO 30 c. CVSO 30 c is calculated to have a period of 27,000 years and a semimajor axis of 660 AU.

Direct imaging of the suspected CVSO 30 c, with a calculated mass equal to 4.7 Jupiter's, has been achieved through photometric and spectroscopic high contrast observations carried out with the Very Large Telescope located in Chile, the Keck Observatory in Hawaii and the Calar Alto Observatory in Spain.[6] However, the colors of the object suggest that it may actually be a background star, such as a K-type giant or a M-type subdwarf.[7]

 
Light curves for CVSO 30, adapted from Koen (2021)[8]

By 2020, the phase of "dips" caused by suspected planet CVSO 30 b had drifted nearly 180 degrees from the expected value, thus ruling out the existence of the planet. Instead, a rare type of stellar starspot activity with very large starspots is now suspected. Also, CVSO 30 is suspected to be a stellar binary, with the previously reported planetary orbital period equal to the rotation period of the companion star.[9] Further investigation of "dips" by 2022 led to hypothesis of a large gas cloud close to synchronous orbit, dust would likely sublimate.[10]

References

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  1. ^ a b c d e f "CVSO 30". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 5 October 2018.
  2. ^ a b c d e f Van Eyken, Julian C.; et al. (2012). "The Ptf Orion Project: A Possible Planet Transiting a T-Tauri Star". The Astrophysical Journal. 755 (1): 42. arXiv:1206.1510. Bibcode:2012ApJ...755...42V. doi:10.1088/0004-637X/755/1/42. S2CID 2753064.
  3. ^ "Extrasolar Planets Encyclopaedia". Archived from the original on 19 February 2019. Retrieved 15 November 2016.
  4. ^ Briceño, Cesar; Calvet, Nuria; Hernández, J.; Vivas, A. K.; Hartmann, Lee; Downes, J. J.; Berlind, Perry (February 2005). "The CIDA Variability Survey of Orion OB1. I. The Low-Mass Population of Ori OB1a and 1b". The Astronomical Journal. 129 (2): 907–926. arXiv:astro-ph/0410521. Bibcode:2005AJ....129..907B. doi:10.1086/426911. ISSN 0004-6256.
  5. ^ Briceno, Cesar; Hartmann, Lee; Hernandez, Jesus; Calvet, Nuria; Vivas, A. Katherina; Furesz, Gabor; Szentgyorgyi, Andrew (June 2007). "25 Orionis: A Kinematically Distinct 10 Myr Old Group in Orion OB1a". The Astrophysical Journal. 661 (2): 1119–1128. arXiv:astro-ph/0701710. Bibcode:2007ApJ...661.1119B. doi:10.1086/513087. ISSN 0004-637X.
  6. ^ "Amazing Photo Shows Likely Alien Planet 1,200 Light-Years Away". MSN. 21 June 2016. Archived from the original on 11 August 2016. Retrieved 22 June 2016.
  7. ^ Lee, Chien-Hsiu; Chiang, Po-Shih (2018). "Evidence that the Planetary Candidate CVSO30c is a Background Star from Optical, Seeing-limited Data". The Astrophysical Journal. 852 (2): L24. arXiv:1712.08727. Bibcode:2018ApJ...852L..24L. doi:10.3847/2041-8213/aaa40b. S2CID 119270170.
  8. ^ Koen, C. (March 2021). "Starspot modelling of the TESS light curve of CVSO 30". Astronomy and Astrophysics. 647: L1. Bibcode:2021A&A...647L...1K. doi:10.1051/0004-6361/202140400. hdl:10566/6123. Retrieved 16 November 2022.
  9. ^ Koen, C.; et al. (2020). "Properties of CVSO 30 from TESS measurements: Probably a binary T Tauri star with complex light curves and no obvious planets". Monthly Notices of the Royal Astronomical Society. 494 (3): 4349–4356. arXiv:2005.10253. doi:10.1093/mnras/staa1038.
  10. ^ Bischoff, R.; et al. (2022). "YETI follow-up observations of the T Tauri star CVSO 30 with transit-like dips". Monthly Notices of the Royal Astronomical Society. arXiv:2201.12405. doi:10.1093/mnras/stac293.

Further reading

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