| Planetary
Nebula
aka NGC 1514, PNG 165.5-15.2, PK 165-15.1, ARO 21 Integrated Visual Magnitude: 10.0 Magnitude of Central Star: 9.4 Apparent Diameter: 2.2' Distance: 2300 ly Mean Surface Brightness: 20.3 mag/arc-sec2 Minimum requirements to view: a 6-inch scope under dark skies |
At first glance the 9th magnitude central star of this planetary nebula
all but drowns out the surrounding nebulosity. This is particularly
true on those cold winter nights when Taurus is high in the sky and the bright stars take on halos.
The roundish glow surrounding this star can look like just another halo.
Because it can be so easily overlooked the trick to finding this one is
to first identify the 9th magnitude central star. This star is the center
of three 9th magnitude stars that make a nearly straight line. These three
stars are obvious at low power.
It is when the magnification is increased that the nebula becomes more apparent. In my 6-inch I could make out a round glow at 133x. I found the best view in my 18-inch to be at 166x, where a very faint haze with hints of structure can be glimpsed without a filter. An OIII or UHC filter really brings this one out. With the OIII in place a dark center appeared and blotchy markings could be glimpsed in the surrounding, fairly round, nebula. The markings are no doubt the dark patches seen in the image at the right.
In even larger instruments the nebula is said to appear box shaped and a faint outer envelope appears. The structure seen in photographs is readily apparent.
William Herschel wrote of this nebula:The view in a 6 inch at 50X. North is down and east is to the right.
A most singular phenomenon! A star of about 8th magnitude with a faint luminous atmosphere, of circular form, and about 3 minutes in diameter. The star is in the centre, and the atmosphere is so faint and delicate and equal throughout that there can be no surmise of its consisting of stars; nor can there be a doubt of the evident connection between the atmosphere and the star.At the time it was commonly assumed that all nebulae were swarms of faint stars that were unresolved; something that is true of many objects such as galaxies. NGC 1514 and a few other planetary nebulae gave Herschel some pause concerning this assumption.
| Millennium
Star Atlas Vol I Chart 139
Sky Atlas 2000 Chart 5 Uranometria 2000 Vol I Chart 95 |
