외계 혜성: 두 판 사이의 차이

'''외계 혜성'''은 태양계 외 [[행성계]]에 존재하는 혜성이다.<ref>{{저널 인용|last=Beust|first=H.|date=1994|title=β Pictoris: The "Falling Evaporating Bodies" Model|journal=CDDP|language=en|volume=10|pages=35|bibcode=1994cddp.conf...35B}}</ref><ref>{{저널 인용|last=Vidal-Madjar|first=A.|last2=Lagrange-Henri|first2=A.-M.|last3=Feldman|first3=P. D.|last4=Beust|first4=H.|last5=Lissauer|first5=J. J.|last6=Deleuil|first6=M.|last7=Ferlet|first7=R.|last8=Gry|first8=C.|last9=Hobbs|first9=L. M.|last10=McGrath|first10=M. A.|last11=McPhate|first11=J. B.|date=October 1994|title=HST-GHRS observations of β Pictoris: additional evidence for infalling comets|journal= Astronomy and Astrophysics|language=en|volume=290|pages=245–258|issn=0004-6361|bibcode=1994A&A...290..245V}}</ref><ref name="Ferlet et al.1987">{{저널 인용| bibcode=1987A&A...185..267F |title=The Beta Pictoris circumstellar disk. V - Time variations of the CA II-K line|author1=Ferlet, R. |author2=Vidal-Madjar, A. |author3= Hobbs, L. M. |last-author-amp=yes |year=1987|journal=[[Astronomy and Astrophysics]]|volume=185|pages=267–270}}</ref><ref name="Beust1990">{{저널 인용|bibcode=1990A&A...236..202B |title=The Beta Pictoris circumstellar disk. X - Numerical simulations of infalling evaporating bodies |last1=Beust |first1=H. |last2=Lagrange-Henri |first2=A.M. |last3=Vidal-Madjar |first3=A. |last4=Ferlet |first4=R. |volume=236 |year=1990 |pages=202–216 |journal=Astronomy and Astrophysics}}</ref> 첫번째 외계 혜성은 1987년 [[A형 주계열성]]인 [[화가자리 베타]]에서 최초로 발견되었다.발견되었으며, 2019년 2월 현재 외계 혜성이 관찰되거나 의심되는 총 27개의 행성계가 있다.<ref name=":2">{{저널 인용|last=Welsh|first=Barry Y.|last2=Montgomery|first2=Sharon L.|date=February 2018|title=Further detections of exocomet absorbing gas around Southern hemisphere A-type stars with known debris discs|journal=MNRAS|language=en|volume=474|issue=2|pages=1515–1525|doi=10.1093/mnras/stx2800|issn=0035-8711|bibcode=2018MNRAS.474.1515W}}</ref><ref name="arXiv:1509.03622">{{저널 인용|title=Planet Hunters IX. KIC 8462852 – where's the flux? |journal=[[Monthly Notices of the Royal Astronomical Society]] |last1=Boyajian |authorlink1=Tabetha S. Boyajian |first1=T. S. |last2=LaCourse |first2=D. M. |last3=Rappaport |first3=S. A. |last4=Fabrycky |first4=D. |last5=Fischer |first5=D. A. |last6=Gandolfi |first6=D. |last7=Kennedy |first7=G. M. |last8=Liu |first8=M. C. |last9=Moor |first9=A. |last10= Olah |first10=K. |last11=Vida |first11=K. |last12=Wyatt |first12=M. C. |last13=Best |first13=W. M. J. |last14=Ciesla |first14=F. |last15=Csak |first15=B. |last16=Dupuy |first16=T. J. |last17=Handler |first17=G. |last18=Heng |first18=K. |last19=Korhonen |first19=H. |last20= Kovacs |first20=J. |last21=Kozakis |first21=T. |last22=Kriskovics |first22=L. |last23=Schmitt |first23=J. R. |last24=Szabo |first24=Gy. |last25=Szabo |first25=R. |last26=Wang |first26=J. |last27=Goodman |first27=S. |last28=Hoekstra |first28=A. |last29=Jek |first29=K. J. |display-authors=1 |volume=457 |issue=4 |pages=3988–4004 |date=April 2016 |doi=10.1093/mnras/stw218 |bibcode=2016MNRAS.457.3988B |arxiv=1509.03622}}</ref> 여태까지 발견된 외계혜성은 모두 모항성이 A형 [[주계열성]]으로, [[원시별]] 단계를 막 지난 어린 별이 절대 다수다.<ref name="Lagrange-Henri et al.1990">{{저널 인용|author1=Lagrange-Henri, A. M.|author2=Beust, H.|author3=Ferlet, R.|author4=Vidal-Madjar, A.|author5=Hobbs, L. M.|last-author-amp=yes|year=1990|title=HR 10 - A new Beta Pictoris-like star?|journal=[[Astronomy and Astrophysics]]|volume=227|pages=L13–L16|bibcode=1990A&A...227L..13L}}</ref><ref name="Lecavelier Des Etangs et al.1997">{{저널 인용|author=Lecavelier Des Etangs, A.|display-authors=etal|year=1997|title=HST-GHRS observations of candidate &beta; Pictoris-like circumstellar gaseous disks.|journal=[[Astronomy and Astrophysics]]|volume=325|pages=228–236|bibcode=1997A&A...325..228L}}</ref> 그렇지만 상대적으로 오래된 별인 Phi Leonis [[스펙트럼]]에서 exocomets의혜성으로 증거를추정되는 보여준다물체가 발견되었다.<ref>{{저널 인용|last=Eiroa|first=C.|last2=Rebollido|first2=I.|last3=Montesinos|first3=B.|last4=Villaver|first4=E.|last5=Absil|first5=O.|last6=Henning|first6=Th|last7=Bayo|first7=A.|last8=Canovas|first8=H.|last9=Carmona|first9=A.|last10=Chen|first10=Ch|last11=Ertel|first11=S.|date=2016-10-01|title=Exocomet signatures around the A-shell star φ Leonis?|journal=Astronomy & Astrophysics|language=en|volume=594|pages=L1|arxiv=1609.04263|doi=10.1051/0004-6361/201629514|issn=0004-6361}}</ref> 이후 오래된 F2V 형 별인 [[까마귀자리 에타]] 주변에서 외계 혜성이 발견되었다.<ref name="Beust1990">{{저널 인용|bibcode=1990A&A...236..202B |title=The Beta Pictoris circumstellar disk. X - Numerical simulations of infalling evaporating bodies |last1=Beust |first1=H. |last2=Lagrange-Henri |first2=A.M. |last3=Vidal-Madjar |first3=A. |last4=Ferlet |first4=R. |volume=236 |year=1990 |pages=202–216 |journal=Astronomy and Astrophysics}}</ref> 2018 년 에2018년에 [[케플러 우주 망원경의우주망원경]]의 데이터를 사용하여 또 다른 F형 별 주변에서 외계 혜성이 발견되었다.