Willman 1

	Willman I
Soort stelsel	Dwergsterrestelsel / sterreswerm
Sterrebeeld	Groot Beer
	Waarnemingsdata (Epog J2000)
Regte klimming	10h 49m 22,3s
Deklinasie	+51º 03' 03,6"
Skynmagnitude	15,2
	Besonderhede
Afstand (ligjaar)	120 000
Skynbare grootte	15′.2
Ander name	SDSS J1049+5103
Portaal	Sterrekunde

Willman I is ’n dwergsterrestelsel of sterreswerm^[1] met ’n besonder lae ligsterkte. Dit is genoem na Beth Willman van die Haverford-kollege, die belangrikste skrywer van ’n studie geskoei op die data van die Sloan Digitale Lugopname.

Dit is ’n elliptiese satellietstelsel van die Melkweg en sowat 120 000 ligjare van die Son af.^[2] Dit is naas Segue 3 die dofste sterrestelsel bekend, met ’n absolute magnitude van −2,7.^[3] Sy massa is na raming sowat 0,4 miljoen sonmassas, en die verhouding tussen sy ligsterkte en massa is dus sowat 800. Dit beteken Willman I word oorheers deur donker materie.

Sy sterre is ouer as 10 miljard jaar en het ’n baie lae metaalinhoud.

Verwysings wysig

↑ Willman, Beth; Geha, Marla; Strader, Jay; Strigari, Louie; Simon, Josh; Kirby, Evan; West, Ho; Nhung, Warres et al. (Oktober 2011), "Willman 1—A Probable Dwarf Galaxy with an Irregular Kinematic Distribution", AJ 142 (4): 128, doi:10.1088/0004-6256/142/4/128, Bibcode: 2011AJ....142..128W, http://adsabs.harvard.edu/abs/2011AJ....142..128W
↑ Willman, Beth; Blanton, Michael R.; West, Andrew A.; Dalcanton, Julianne J.; Hogg, David W.; Schneider, Donald P.; Wherry, Nicholas; Yanny, Brian et al. (2005), "A New Milky Way Companion: Unusual Globular Cluster or Extreme Dwarf Satellite?", The Astronomical Journal 129 (6): 2692–2700, doi:10.1086/430214, Bibcode: 2005AJ....129.2692W, http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=2005AAS...207.9101W
↑ Martin, N.F.; De Jong, J.T.A.; Rix, H.W. (2008). "A Comprehensive Maximum Likelihood Analysis of the Structural Properties of Faint Milky Way Satellites". The Astrophysical Journal. 684 (2): 1075. doi:10.1086/590336.{{cite journal}}: CS1 maint: ref duplicates default (link)

Koördinate: 10^h 49^m 22.3^s, +51° 03′ 03.6″

Hierdie artikel is vertaal uit die Engelse Wikipedia

[1] Willman, Beth; Geha, Marla; Strader, Jay; Strigari, Louie; Simon, Josh; Kirby, Evan; West, Ho; Nhung, Warres et al. (Oktober 2011), "Willman 1—A Probable Dwarf Galaxy with an Irregular Kinematic Distribution", AJ 142 (4): 128, doi:10.1088/0004-6256/142/4/128, Bibcode: 2011AJ....142..128W, http://adsabs.harvard.edu/abs/2011AJ....142..128W

[2] Willman, Beth; Blanton, Michael R.; West, Andrew A.; Dalcanton, Julianne J.; Hogg, David W.; Schneider, Donald P.; Wherry, Nicholas; Yanny, Brian et al. (2005), "A New Milky Way Companion: Unusual Globular Cluster or Extreme Dwarf Satellite?", The Astronomical Journal 129 (6): 2692–2700, doi:10.1086/430214, Bibcode: 2005AJ....129.2692W, http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=2005AAS...207.9101W

[3] Martin, N.F.; De Jong, J.T.A.; Rix, H.W. (2008). "A Comprehensive Maximum Likelihood Analysis of the Structural Properties of Faint Milky Way Satellites". The Astrophysical Journal. 684 (2): 1075. doi:10.1086/590336.{{cite journal}}: CS1 maint: ref duplicates default (link)

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