EPIC 204376071

EPIC 204376071

Context star field of EPIC 204376071
Observation data
Epoch J2000.0 (ICRS)      Equinox ICRS
Constellation Scorpius[1]
Right ascension 16h 04m 10.1267s[2]
Declination −22° 34′ 45.550″[2]
Apparent magnitude (V) 18.0[3]
Characteristics
Evolutionary stage M[4]
Astrometry
Proper motion (μ) RA: −11.544[2] mas/yr
Dec.: −24.892[2] mas/yr
Parallax (π)7.3908±0.1944 mas[2]
Distance440 ± 10 ly
(135 ± 4 pc)
Details
Mass0.161±0.028[4][5] M☉
Radius0.631±0.042[5] R☉
Luminosity (bolometric)0.0273±0.0020[4] L☉
Temperature2960±75[4] K
Rotation1.63 days[6]
Age10[7] Myr
Other designations
UScoCTIO 48, 2MASS J16041012-2234453[2]
Database references
SIMBADdata

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.[4][5][7] It is likely a member of the Upper Sco association, and is young enough that it has not yet become a main-sequence star.[4]

A light curve for EPIC 204376071, adapted from Rappaport et al. (2019).[5] 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.[5][7] The unusual dimming was not only extremely deep, but also substantially asymmetric, with an egress about twice as long as the ingress.[6] Nonetheless, such an unusual dimming for EPIC 204376071 is much greater than the 22% dimming observed for Tabby's star.[8][9] 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".[5] 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.[7]

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

See also

References

  1. ↑ Roman, Nancy G. (1987). "Identification of a constellation from a position". Publications of the Astronomical Society of the Pacific. 99 (617): 695. Bibcode:1987PASP...99..695R. doi:10.1086/132034. Constellation record for this object at VizieR.
  2. 1 2 3 4 5 6 Staff (2019). "EPIC 204376071 -- Star in Association". SIMBAD. Retrieved 6 March 2019.
  3. ↑ Girard, Terrence M.; Van Altena, William F.; Zacharias, Norbert; Vieira, Katherine; Casetti-Dinescu, Dana I.; Castillo, Danilo; Herrera, David; Lee, Young Sun; Beers, Timothy C.; Monet, David G.; López, Carlos E. (2011). "The Southern Proper Motion Program. IV. The SPM4 Catalog". The Astronomical Journal. 142 (1): 15. arXiv:1104.5708. Bibcode:2011AJ....142...15G. doi:10.1088/0004-6256/142/1/15.
  4. 1 2 3 4 5 6 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.
  5. 1 2 3 4 5 6 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.
  6. 1 2 Nowakowski, Tomasz (5 March 2019). "Astronomers detect deep, long asymmetric occultation in a newly found low-mass star". Phys.org. Retrieved 6 March 2019.
  7. 1 2 3 4 Starr, Michelle (6 March 2019). "Astronomers Have Discovered Another Mysterious Dimming Star, And It's Even More Epic". ScienceAlert.com. Retrieved 6 March 2019.
  8. ↑ Carpineti, Alfredo (6 March 2019). "We've Just Found Another Mysteriously Dimming Star In The Galaxy". IFLScience.com. Retrieved 6 March 2019.
  9. ↑ Valdez, Rubi (8 March 2019). "Another Dimming EPIC Star Is Likely An Alien Planet, Astronomers Say". Tech Times. Retrieved 8 March 2019.
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