„Hubbles nächste Entdeckung“ Arp 274 im Bild

Ende Janu­ar 2009 hat­te das Space Telescope Sci­ence Insti­tu­te (STScI) zu einer Mit­mach­ak­ti­on auf­ge­ru­fen, um im Rah­men der Akti­on „100 Stun­den Astro­no­mie“ zum IYA 2009 das nächs­te Ziel für das berühm­te Welt­raum­te­le­skop aus­zu­wäh­len. Das wech­sel­wir­ken­de Gala­xien­tri­plet Arp 274 erhielt am Ende der Akti­on 67.021 Stim­men von über 140.000 abge­ge­be­nen und konn­te sich somit gegen sechs wei­te­re Kan­di­da­ten durch­set­zen. Wie ver­spro­chen lich­te­te Hub­ble das Sie­ger­ob­jekt am 1. – 2. April mit der Wide Field and Pla­ne­ta­ry Came­ra 2 ab.

Das Drei­er­sys­tem Arp 274, bekannt auch als NGC 5679, liegt in einer Ent­fer­nung von rund 400 Mil­lio­nen Licht­jah­ren (120 Mpc) im Stern­bild Jung­frau (Vir­go). Der Abstand zwi­schen dem lin­ken und rech­ten Bild­rand beträgt 2 Bogen­mi­nu­ten, was einer tat­säch­li­chen Aus­deh­nung von rund 216.000 Licht­jah­ren entspricht. 

Arp 274, also known as NGC 5679, is a sys­tem of three gala­xies that appear to be par­ti­al­ly over­lap­ping in the image, alt­hough they may be at some­what dif­fe­rent distances. The spi­ral shapes of two of the­se gala­xies appear most­ly int­act. The third gala­xy (to the far left) is more com­pact, but shows evi­dence of star formation.

Two of the three gala­xies are forming new stars at a high rate. This is evi­dent in the bright blue knots of star for­ma­ti­on that are strung along the arms of the gala­xy on the right and along the small gala­xy on the left.

The lar­gest com­po­nent is loca­ted in the midd­le of the three. It appears as a spi­ral gala­xy, which may be bar­red. The enti­re sys­tem resi­des at about 400 mil­li­on light-years away from Earth in the con­stel­la­ti­on Virgo.

Hubble’s Wide Field Pla­ne­ta­ry Came­ra 2 was used to image Arp 274. Blue, visi­ble, and infrared fil­ters were com­bi­ned with a fil­ter that iso­la­tes hydro­gen emis­si­on. The colors in this image reflect the intrin­sic color of the dif­fe­rent stel­lar popu­la­ti­ons that make up the gala­xies. Yel­lo­wish older stars can be seen in the cen­tral bul­ge of each gala­xy. A bright cen­tral clus­ter of stars pin­point each nucleus. Youn­ger blue stars trace the spi­ral arms, along with pin­ki­sh nebu­lae that are illu­mi­na­ted by new star for­ma­ti­on. Inter­stel­lar dust is sil­hou­et­ted against the star­ry popu­la­ti­on. A pair of fore­ground stars insi­de our own Mil­ky Way are at far right.

Quel­le: Hubblesite.org