View source for EPIC 204278916

{{Use dmy dates|date=September 2016}}
{{Starbox begin
 | name = EPIC 204278916
 }}
{{Starbox observe
 | epoch = [[J2000.0]] ([[International Celestial Reference System|ICRS]])
 | constell = [[Scorpius]]
 | pronounce = <!--Pronunciation guide-->
 | ra = {{RA|16|02|07.576}}
 | dec = {{DEC|-22|57|46.89}}
 | appmag_v = <!--{{val|p=||}}-->
 }}
{{Starbox character
 | type = [[Pre-main-sequence star|Pre-main-sequence]]
 | class = [[Red dwarf|M1]]
 | r-i = <!--R−I color-->
 | v-r = <!--V−R color-->
 | b-v = <!--B−V color-->
 | u-b = <!--U−B color-->
 | j-h = 0.712
 | j-k = 1.033
 }}
{{Starbox astrometry
 | prop_mo_ra = {{val|-13.5|8.7}}
 | prop_mo_dec = {{val|-20.0|8.8}}
 | parallax = <!--Parallax (in milliarcsec)-->
 | p_error = <!--Parallax error (in milliarcsec)-->
 | parallax_footnote = <!--Parallax footnote-->
 | dist_ly = <!--Distance (in light years)-->
 | dist_pc = <!--Distance (in parsecs)-->
 }}
{{Starbox detail
 | mass = 0.5
 | radius = 0.97
 | luminosity_bolometric = 0.15
 | age_myr = ≈5
 }}
{{Starbox catalog
 | names = [[2MASS]] J16020757-2257467, [[UCAC2]] 22721863, [[USNO]]-B1.0 0670-00406583
 }}
{{Starbox reference
 | Simbad = 2MASS+J16020757-2257467
 }}
{{Starbox end}}

'''EPIC 204278916''' is a [[pre-main-sequence star]], about five million years old and of spectral type [[red dwarf|M1]]. It is part of the Upper Scorpius sub-group of the [[Scorpius–Centaurus Association]], and is in the constellation [[Scorpius]]. The star is approximately the size of the Sun at {{solar radius|0.97}}, but is only half its mass ({{solar mass|0.50}}) and a fraction of its luminosity ({{solar luminosity|0.15}}).<ref name="EPIC">{{cite journal |title=The peculiar dipping events in the disk-bearing young-stellar object EPIC 204278916 |journal=Monthly Notices of the Royal Astronomical Society, Advanced Access |first1=S. |last1=Scaringi |first2=C. F. |last2=Manara |first3=S. A. |last3=Barenfeld |first4=P. J. |last4=Groot |first5=A. |last5=Isella |first6=M. A. |last6=Kenworthy |first7=C. |last7=Knigge |first8=T. J. |last8=Maccarone |first9=L. |last9=Ricci |first10=M. |last10=Ansdell |display-authors=5 |date=August 2016 |doi=10.1093/mnras/stw2155 |bibcode=2016MNRAS.tmp.1267S |arxiv=1608.07291}}</ref><ref name="Phys2016Org">{{cite news |url=http://phys.org/news/2016-08-irregular-dimming-young-stellar-astronomers.html |title=Irregular dimming of a young stellar object investigated by astronomers |work=Phys.org |last=Nowakowski |first=Tomasz |date=30 August 2016 |accessdate=5 September 2016}}</ref>

This stellar object was first characterized by the 2nd [[USNO CCD Astrograph Catalog]] and the [[2MASS|Two Micron All-Sky Survey]], and was further studied during the ''[[Kepler (spacecraft)|Kepler]]'' space telescope's extended ''K2'' mission Campaign 2 between 23 August and 13 November 2014.

== Luminosity ==
Research conducted by a team of astronomers, led by Simone Scaringi of the [[Max Planck Institute for Extraterrestrial Physics]] in Germany, found that this [[red dwarf]] star has a resolved [[circumstellar disc]], and luminosity dimmings of up to 65% for 25 consecutive days (out of 79 total observation days) were observed. The variability is highly periodic and attributed to stellar rotation. The researchers hypothesize that the ''irregular'' dimmings are caused by either a warped inner-disk edge or transiting cometary-like objects in either circular or eccentric orbits.<ref name="EPIC" />

==See also==
* [[KIC 8462852]], a star showing similar light fluctuations

==References==
{{reflist}}

{{Portal bar|Astronomy|Space}}

{{Stars of Scorpius}}

[[Category:Astronomical objects discovered in 2015]]
[[Category:Scorpius (constellation)]]
[[Category:M-type main-sequence stars]]
[[Category:Pre-main-sequence stars]]
[[Category:2MASS objects]]

{{reddwarf-star-stub}}