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Treasure Chest

by Perry Pezzolanella, MVAS

As the nights begin to lengthen and the clear air of autumn returns, the bright constellations of winter begin reappearing. One constellation that is high in the north in the late evening is Cepheus, the King, which has a hidden treasure chest that packs more jewels in a low-power eyepiece than seems imaginable. At the bottom of the house-shaped Cepheus is a sparkling red star, a golden double sun, a silvery triple star, and a large open cluster all imbedded in the glow of a huge nebula, This makes five deep sky objects within a single field of view less than 1 degree across.

Using the chart that follows, the tour begins with Mu Cephei, also known as Sir William Herschel's Garnet Star. It is an unusually deep orange-red variable star ranging in brightness from magnitude +3.4 to +5.1 with an irregular period, so watch for its changes. It is a huge supergiant star that would engulf all of the planets out to Saturn if it replaced the Sun. It owes its Mars-like color to the fact that it is a cool star no more than 4000-6000 F.

Struve 2819 is double star with a magnitude of +7.4 and +8.7 and a separation of 12 arc-seconds. The pair splits cleanly in the smallest telescope and the golden hue makes them appear like a pair of miniature suns.

Struve 2816 is a fascinating triple star and a rare sight to behold. Two 8th magnitude stars flank a brighter, magnitude +5.7 star and are separated by 12 and 20 arc-seconds from the brighter primary star.

These stars are set among a scattering of four to five dozen dimmer stars of an open cluster known as IC1396. The cluster is dim compared to the brighter stars nearby and those within it that it can be overlooked unless seen from a dark sky. This cluster spans 50 arc-minutes across, which is nearly twice as large as the full Moon.

To add to the beauty of this regal region, all of this is set against a faint, diffuse emission nebula that spans up to 170 arc-minutes across or roughly five times as large as the full Moon. A very clear night with dark skies and perfect vision are mandatory in order to see the nebula that resembles a faint version of the Rosette Nebula in Monoceros. The nebula and open cluster together are referred to as IC1396. A prominent dark cloud called the Elephant Trunk stretches into the nebula and is a cold region containing raw materials for future star birth. Spectacular narrowband color imaging using sulfur II, hydrogen-alpha, and oxygen III filters are revealing incredible depth, texture, and color never seen before in this region.

The night sky is full of treasures for telescopes of all sizes and it is even more fun to find a bunch of them nestled into one compact region of the sky. This takes less time and effort to locate them and leaves more time for fun observing them. The region within and surrounding IC1396 fits the bill and is truly full of celestial jewels worthy of a king.