EPIC 204376071 is an M-type star in the constellation of Scorpius. Parallax measurements by the Gaia space observatory put the star at a distance of about 440 light-years (130 parsecs) from Earth.[2][3][5] It is likely a member of the Upper Sco association, and is young enough that it has not yet become a main-sequence star.[2]

A light curve for EPIC 204376071, adapted from Rappaport et al. (2019).[3] The inset plot shows the time around the dimming with an expanded scale.

Unusual light fluctuations of the star, including up to an 80% dimming in brightness (i.e., "single 80% deep occultation of 1-day duration"), were observed by astronomers.[3][5] The unusual dimming was not only extremely deep, but also substantially asymmetric, with an egress about twice as long as the ingress.[4] Nonetheless, such an unusual dimming for EPIC 204376071 is much greater than the 22% dimming observed for Tabby's star.[6][7] Several explanations have been presented to explain the unusual dimming of the EPIC 204376071 star: one, orbiting dust or small particles; or two, a "transient accretion event of dusty material near the corotation radius of the star".[3] The unusual light curve of the star is similar to the light curve of a candidate exoplanet, KIC 10403228 b, which may have been caused by a "tilted ring system" orbiting the planet. In the case of EPIC 204376071, an orbiting brown dwarf or large planet, with a ring system, could cause a similar light curve, according to the researchers.[5]

Artist's concept of dust or small particles orbiting a star.

See also

References

  1. ^ a b c d e f Staff (2019). "EPIC 204376071 -- Star in Association". SIMBAD. Retrieved 6 March 2019.
  2. ^ a b c d e f Rappaport, S.; et al. (22 February 2019). "Deep Long Asymmetric Occultation in EPIC 204376071" (PDF). Monthly Notices of the Royal Astronomical Society. 485 (2): 2681–2693. arXiv:1902.08152. Bibcode:2019MNRAS.485.2681R. doi:10.1093/mnras/stz537. S2CID 119470865. Retrieved 6 March 2019.
  3. ^ a b c d e f Rappaport, S.; et al. (22 February 2019). "Deep Long Asymmetric Occultation in EPIC 204376071". Monthly Notices of the Royal Astronomical Society. 485 (2): 2681–2693. arXiv:1902.08152. Bibcode:2019MNRAS.485.2681R. doi:10.1093/mnras/stz537. S2CID 119470865.
  4. ^ a b Nowakowski, Tomasz (5 March 2019). "Astronomers detect deep, long asymmetric occultation in a newly found low-mass star". Phys.org. Retrieved 6 March 2019.
  5. ^ a b c d Starr, Michelle (6 March 2019). "Astronomers Have Discovered Another Mysterious Dimming Star, And It's Even More Epic". ScienceAlert.com. Retrieved 6 March 2019.
  6. ^ Carpineti, Alfredo (6 March 2019). "We've Just Found Another Mysteriously Dimming Star In The Galaxy". IFLScience.com. Retrieved 6 March 2019.
  7. ^ Valdez, Rubi (8 March 2019). "Another Dimming EPIC Star Is Likely An Alien Planet, Astronomers Say". Tech Times. Retrieved 8 March 2019.


Allikas: https://en.wikipedia.org/wiki/EPIC_204376071
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