Cosmic bubble NGC 6781

Stars such as our Sun do not contain enough mass to finish their lives in the glorious explosions known as supernovae. However, they are still able to salute their imminent demise into dense, Earth-sized embers called white dwarfs by first expelling colourful shells of gas known as planetary nebulae. This misnomer comes from the similarity in appearance of these spherical mass expulsions to giant planets when seen through small telescopes.

NGC 6781 is a nice representative of these cosmic bubbles. The planetary nebula lies a few thousand light-years away towards the constellation of Aquila (the Eagle) and is approximately two light-years across. Within NGC 6781, shells of gas blown off from the faint, but very hot, central star’s surface expand out into space. These shells shine under the harsh ultraviolet radiation from the progenitor star in intricate and beautiful patterns. The central star will steadily cool down and darken, eventually disappearing from view into cosmic oblivion.

This image was captured with the ESO Faint Object Spectrograph and Camera (EFOSC2) through three wide band filters (B, V, R) and two narrow-band ones (H-alpha, OIII). EFOSC2 is attached to the 3.6-metre telescope at ESO’s La Silla Observatory in Chile. EFOSC2 has a field of view of 4.1 x 4.1 arcminutes.

Crédit:

ESO

À propos de l'image

Identification:ngc6781-potw
Type:Observation
Date de publication:3 décembre 2009 23:21
Taille:1766 x 1766 px

À propos de l'objet

Nom:NGC 6781
Type:Milky Way : Nebula : Type : Planetary
Constellation:Aquila
Catégorie:Nebulae

Formats des images

Grand JPEG
965,3 Kio
JPEG taille écran
220,1 Kio

Fonds d'écran

1024x768
216,7 Kio
1280x1024
370,9 Kio
1600x1200
596,3 Kio
1920x1200
626,3 Kio
2048x1536
849,3 Kio

Coordinates

Position (RA):19 18 28.01
Position (Dec):6° 32' 20.85"
Field of view:4.64 x 4.64 arcminutes
Orientation:North is 1.1° right of vertical

 

Voir aussi notre