The Little Gem is a stunning blue-green planetary nebula that shines brightly within the southern sky close to Sagittarius’ Teapot tonight.
The Little Gem Nebula, cataloged as NGC 6818, is a shiny, compact planetary nebula in Sagittarius. Credit score: Michael Breite/Stefan Heutz/Wolfgang Ries/www.ccdguide.com
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August 7: A lunar occultation of the Pleiades
Let’s spend tonight with the Little Gem, a planetary nebula additionally cataloged as NGC 6818. It’s highest within the sky round 11 P.M., when it’s some 35° above the southern horizon. It’s situated within the northeastern nook of Sagittarius, to the higher left of the Teapot asterism at the moment of night time.
To seek out it, find Third-magnitude Beta (β) Capricorni in Capricornus (to the higher left of Sagittarius) and easily slide 9° due west. You’ll need a telescope to take pleasure in this planetary — a small one will do, however as at all times, the bigger the higher. NGC 6818 glows at magnitude 9.3 and spans some 48” on the sky. In a small telescope, it seems about half as massive, roughly 25” throughout. That’s compact sufficient to lend it comparatively excessive floor brightness, making it an amazing goal for smaller scopes, even when you might even see much less total element.
When you do discover NGC 6818, you might even see why it has one other identify: The Inexperienced Mars Nebula. The primary half of that moniker comes from the planetary’s coloration, whose glowing gasoline seems blue-green to the attention. The second half could also be much less apparent, however pertains to the nebula’s perceived measurement on the sky — a diameter of 25” is roughly the identical measurement as Mars throughout its closest approaches to the Solar, so newbie astronomers have likened the looks of this glowing globe to the Pink Planet, for all that their colours are reverse.
Dawn: 6:05 A.M.
Sundown: 8:05 P.M.
Moonrise: 12:59 A.M.
Moonset: 5:09 P.M.
Moon Section: Waning crescent (18%)
*Occasions for dawn, sundown, moonrise, and moonset are given in native time from 40° N 90° W. The Moon’s illumination is given at 10 P.M. native time from the identical location.
The Moon passes 4° north of Mars at 2 A.M. EDT; the pair is seen collectively within the early-morning sky of August 9, some 30° excessive within the east an hour earlier than dawn. They straddle the border of Gemini and Taurus, to the higher left of the acquainted hourglass-shaped determine of Orion the Hunter, bisected by his well-known belt.
Mars is magnitude 1.3, a shiny reddish level of sunshine on this area of the sky, simply to the best of the fragile waning crescent Moon. Increased within the sky and to the best of the pair is the purple big Aldebaran, brighter than Mars at magnitude 0.9 however shining with an identical hue, because of this star’s superior age, which has cooled its temperature. Evaluate each Mars and Aldebaran to Betelgeuse, the magnitude 0.5 purple big shoulder of Orion, which additionally shines orangey-red.
Far beneath and to the left is Mercury, simply 4° above the japanese horizon an hour earlier than dawn. Regardless of its low altitude, it’s shining brightly at magnitude –0.6, making it straightforward to identify so long as your horizon is evident. By a telescope, Mercury spans 6” and is 65% lit. Evaluate that with Mars, whose part is 93% however seems only a bit smaller, 5”. It’s because though Mercury is bodily smaller than Mars, the latter now lies farther from Earth, which diminishes its obvious measurement in our sky.
As at all times, make certain to place away any optics nicely earlier than dawn out of your location, which can differ from the time given beneath.
Alison Klesman is senior editor of Astronomy journal. She holds a Ph.D. in astronomy and has studied a wide range of matters, from minor planets to supermassive black holes.
