Sunday, August 31, 2014

Comet Jacques

Recently windows appeared in the very murky weather that prevails during the summer here along the Gulf Coast. One such window appeared last weekend, which gave me the opportunity to observe a number of old favorites, and to get a good look at an approaching comet. Upon setting up the 15-inch, I discovered the azimuth encoder was slipping badly, so instead of sketching some objects I had on my list, I opted to sketch a couple of summer favorites and Comet Jacques, now an easy object for small telescopes and binoculars.
M-8 or the Lagoon Nebula is probably the finest and brightest object of it's kind in the summer skies visible from the northern hemisphere. Shining at an apparent magnitude of 5.8 and covering a region of sky about 1.5 degrees across in long exposure photos, this object fills most of the field of view at 83X. The 24mm Explore Scientific eyepiece I was using gives a true field of view one degree across in the 15-inch, so I was only seeing the brighter inner region. Light pollution hides the faint outer regions, but when views through an O-III filter from the airstrip a wealth of bright and dark regions appears. The star cluster within the nebula is itself a very nice object to observe. Both are 5,500 light years from Earth. From a truly dark site M-8 would overflow the field with bright and dark patches, streamers and fans of gas and dust. The Hourglass feature was very apparent, and so was the dark channel between it and the enclosed star cluster that gives this nebula it's name. Under good skies M-8 is a wonderful sight even through small telescopes and large binoculars.
M-16 or the Eagle Nebula is another famous nebula, though not as bright as M-8 even though it too is a 6th magnitude object. It extends across an area of sky some 35 arc-minutes wide and is 7,000 light years from Earth. It displays a eagle or at least a flying bird like shape at 111X through an Explore Scientific 18mm 82 degree eyepiece and an O-III filter. With the filter it was easy to make out, without it light pollution at the site rendered it barely visible despite the massive light grasp of the telescope. Visible in the center of the nebula as an irregular triangular dark region are the Pillars of Creation. Other dark nebula are present as well, but I did not see them that night. M-16 was visible through the finder and I also made out nearby M-17 clearly as well.

Comet C/2014E2 Jacques is now an easy object visible in the evening sky as soon as darkness falls. Ever since it came into view in the predawn skies, it has been getting brighter even though it is now outward bound from the Sun. First spotted by the Southern Observatory for Near Earth Asteroids Research in Brazil last March, this comet is now at closest approach to Earth at a distance of .56 A.U or 52 million miles. In July it passed 7.9 million miles from Venus. This is a long period comet which takes 12,000 years to complete it's next orbit around the Sun. At aphelion, it's more than 1,600 A.U. from the Sun, some 13 times farther away than Voyager 1. At the time I observed it at 227X, it was at about seventh magnitude. Lacking a clearly defined nuclear region, it resembled a lopsided elliptical or face-on spiral galaxy with a weak central core. There was persistent signs of a very faint tail. Over a period of 24 hours from the previous night when I observed it from the driveway, it's motion was very evident. It was also clearly visible through the finder scope and was well worth the effort to track down. C/2014E2 Jacques will be close enough for a good view for the next few weeks or months. If you wish to see it before it fades, this is the time to get the best possible view.

While my plans for that night were a bust, it was still an enjoyable evening to be under the stars. I has a nice view of Saturn, observed a number of planetary nebulae and globular clusters, and looked at the Andromeda and Triangulum galaxies. Other objects I observed included Seyfert's Sextet and NGC-7331 in Pegasus, a twin to the Andromeda Galaxy that is 23 times farther away from us. I have since fixed the problem with the azimuth encoder and am looking ahead to the next opportunity to observe under dark skies