deep-sky object


Also found in: Encyclopedia, Wikipedia.

deep-sky object

(dēp′skī′)
n.
Any of various celestial objects, including nebulae, star clusters, and galaxies, that are diffuse and very distant, and therefore faint, usually observable only by means of a telescope.
Mentioned in ?
References in periodicals archive ?
Many resources for beginners and those at intermediate level are available from the ASSA website, including the Southern Star Wheel planisphere, ConCards (constellation and deep-sky object finder charts) and the comprehensive Deepsky Observer's Companion tutorial.
2 -- 3 -- color) Astronomy guide Daniel Manrique, above, trains a telescope on a deep-sky object at the Skywatcher's Inn, where the Galaxy room, above left, plays up the outer space theme.
Once they get past the Moon, bright planets, and a vivid deep-sky object or two, they run out of interesting things to observe.
It's probably the youngest deep-sky object you'll ever see -so young that it has changed significantly since Messier first spotted it.
Many resources for beginners and those at intermediate level are available from the Section, including the Southern Star Wheel planisphere, ConCards (constellation and deep-sky object finder charts), the Discover
If there's one big category of deep-sky object that binoculars are best at showing, it's undoubtedly open clusters.
Hercules is the constellation that spells "summer" for me, and Messier 13, the Great Globular Star Cluster, is undoubtedly Here's premiere deep-sky object.
If I had to choose just one deep-sky object to demonstrate the appeal of binocular astronomy, it would probably be the Pleiades (M45) in Taurus.
Perhaps no constellation is more strongly associated with a single deep-sky object than Andromeda.
Dark nebulae are one class of deep-sky object that doesn't get enough attention.
How high a power I select for any type of deep-sky object (other than big, bright open star clusters) is limited by the transparency of the sky and steadiness of the seeing.
Planetary nebulae are the most poorly represented class of deep-sky object in the Messier catalog, and no wonder--virtually all of them are tiny.