Sky's Up - Fall 2015 - Page 24

haunting beauties This year, the festive and frightful Halloween holiday falls on a Saturday night, which means it will be a perfect time to stay up late to check out some of our night sky’s eeriest treats. The following is a list of some of the most popular spooky sights that dot the universe. Not all of these will be visible from all latitudes, but even if you cannot view them from the field, they are all worth checking out virtually. Witch Head Nebula Our haunting cosmic journey begins with a celestial witch hunt in Eridanus, which is visible from 32° North to 90° South. In this sprawling constellation, a faint but striking reflection nebula conjures up the image of an old crone. A great target for astrophotography, the appropriately named Witch Head Nebula has a mesmerizing blue glow that adds to its creepy quotient. The likely source of this illumination is the nearby blue supergiant Rigel, which is a main attraction in the Orion constellation. COURTESY OF ADAM BLOCK, MOUNT LEMMON SKYCENTER, UNIVERSITY OF ARIZONA 24 COURTESY OF NASA, ESA, HEIC, AND THE HUBBLE HERITAGE TEAM (STSCI/AURA) As complicated as the creature it is associated with, the Cat’s Eye Nebula is a bright planetary nebula that peers out of the night sky near the North Ecliptic Pole with an ominous blue-green glow. Although you can see it in modest telescopes, you will need to use high magnification to reveal any hints of its highly complex structure, which includes curving brown lines and radiating circles. Most will see it as a bluegreen disc with a blazing central star. The nebula, which is located in the Draco constellation, is a great choice for a long-exposure photo. When it comes to nebulae, several are associated with ghosts, but there is one that is particularly unsettling. The Ghost Nebula looms in the Northern Hemisphere’s Cepheus constellation, which is in a prime observation position in November. This wispy reflection nebula manifests an intriguing brownish color around its edges. To one side of its brighter core, dark dust clouds appear as figures straining to break free. On the opposite edge a large dark cloud swirls around a glowing center and could be a harbinger of a binary star system in the making. Owl Nebula COURTESY OF NASA/STSCI DIGITIZED SKY SURVEY/NOEL CARBONI Cat’s Eye Nebula Ghost Nebula Sky’s Up As the Northern Hemisphere eases into fall, Ursa Major’s popular Owl Nebula has definite autumnal appeal. Found below the bowl of the constellation’s famed Big Dipper asterism, the Owl Nebula is a planetary nebula that appears as a greenish disk marred by two dark voids that give the object its owl-like appearance. These “eyes” show up nicely in an 8-inch telescope, and the white dwarf that lurks between them reveals itself in a slightly larger telescope. Long-exposure photos will render a reddish outline around the green-hued core. COURTESY OF MARK SIBOLE Sky’s Up 25