2013 February 24
M51: The Whirlpool Galaxy in Dust and Stars
Image Credit: N. Scoville (Caltech), T. Rector (U. Alaska, NOAO) et al., Hubble Heritage Team, NASA
Image Credit: N. Scoville (Caltech), T. Rector (U. Alaska, NOAO) et al., Hubble Heritage Team, NASA
Explanation: The Whirlpool Galaxy is a classic spiral galaxy. At only
30 million light
years distant and fully 60 thousand light years across, M51, also known as NGC 5194, is one
of the brightest and most picturesque
galaxies on the sky. The above
image is a digital
combination of a ground-based image from the 0.9-meter telescope at Kitt Peak National Observatory and a
space-based image from the Hubble Space Telescope
highlighting sharp features normally too
red to be seen. Anyone with a good pair of binoculars,
however, can see this Whirlpool toward the
constellation
of the Hunting Dogs (Canes
Venatici. M51 is a spiral galaxy of type Sc and
is the dominant member of a whole group of galaxies.
Astronomers speculate that M51's spiral structure
is primarily due to its gravitational interaction with a
smaller galaxy just off the top of the image.
Aucun commentaire:
Enregistrer un commentaire