NGC 7014

Transcription

Salutations celestial sight seers! I'm David Fuller, welcome to Eyes on the Sky; what's up this week? I want to tell you my secret now. Okay. I see dead stars. Movie stars? Dead stars like, in space? In the sky? Floating around like regular stars. They don't shine like other stars. They're visible because of an expanding, glowing shell of ionized gas. How often do you see them? All the time. They're everywhere! YOU can see dead stars too! Some that are easily seen in the night sky are called planetary nebulae. A few well known ones are the Ring Nebula and the Dumbbell Nebula, both of which have been highlighted by Eyes on the Sky previously. And one, that surprisingly was overlooked by Charles Messier when he made his famoust list of non-comets, is NGC 7009, sometimes called the Saturn Nebula. I'll be right back to show you how to find this shell of a star. Dark Sky Fact: The Shropshire Council in western England voted to continue a policy of turning of streetlamps from midnight to 5:30 am. Not only does this save the county money, Superintendent James Tozer said: "Since this ...began, crime has actually gone down. There has been a 34 per cent fall in the number of burglaries since last year." NGC7009 is not all that difficult to find, and is bright enough it can even been seen with a 90mm telescope while the Moon is full! Around 8 or 9 o'clock in the evening, and holding two fists together at arm's-length, measure 20 degrees from Fomalhaut towards Altair. This will place you at the eastern side of Capricornus the Sea Goat, and the stars Deneb Algiedi and Nashira are here. Drawing a line through them back towards the western side of the constellation in the direction of Dabih (DAH-bee), use the finderscope on a small telescope to hop first to Iota, then one more similarly distanced hop to Theta Capricorni -- both 4-th magnitude stars. Observers with a well-aligned equatorial mount and large setting circles can simply dial their telescopes 6 degrees north to center the Saturn Nebula. But for star hoppers, place those two stars on either side of the field of view, then move perpendicular to the line they create, about a full finderscope field of view. This will get you to Nu Aquarii, a 4.5 magnitude star. NGC7009 is just a degree and a half away from it, but there isn't really an easy pointer star. So just move in the same direction as the Iota -- Theta line. That's where the nebula will be! Look for a star that seems slightly out of focus with a wide field of view. Even in a 90mm telescope I see a pale blue color to the nebula. But this object is better observed at higher magnifications, as it has high surface brightness. Try for 150, 200 or even higher powers if your telescope can handle it. Larger apertures under dark skies may see the lobes or even antenna that appear off the sides of this nebula, but even very small telescope can see the oval, non-circular shape to this shell of a dying star. Along The Ecliptic: After hopping over Antares last week, Venus looks to leapfrog Messiers 6 and 7 next week, approaching them across the course of this week. Jupiter can rightly be called an evening as well as morning object now, as it attains more than 10 degrees of altitude before midnight now, with the Moon joining it on the 25-th. And Mars darts within a few degrees of one of the Leo Triplet of galaxies by the weekend. That's all for this week. Keep your eyes on the sky and your outdoor lights aimed down, so we can all see, what's up. I'm David Fuller, wishing you clear and dark skies.