The year goes on, and it does so the night sky. In the northern hemisphere, to begin in the summer, the deep-sky objects to make an appearance late in the evening - Favorite bright stars like Vega and Arcturus in the Bootes constellation of Lyra a return from the East, and with them some stunning Deep-Messier objects of the sky. A couple of hours looking at the end of April showed some real stunners, including M13, M92 e. Much later, I should be able to see M3 in Canes Venatici constellation, andM57 (Ring Nebula) in the constellation of Lyra, but quite bad light pollution of the local industry on the eastern horizon of my observation only deep deep sky objects with low surface brightness, such as planetary nebulae, galaxies and star clusters.
I always tend to an eyepiece 26 mm or 20 mm, the first time in the display of deep sky objects, with success feeding them in my viewfinder. Sometimes, as in the case of M81 (Bode's Nebula) and M82 (Cigar Galaxy, i)Ursa Major, the smaller eyepiece and wide field of view allows you to frame along with attractive deep-sky objects. When it's time for a closer look, I increase the magnification with my Celestron Barlow Lens x2. In my situation, with moderate light pollution and without filters, the most deep sky objects, because they are so weak, in fact no longer tolerate high magnification with a 200mm aperture reflector, except, of course, star clusters and bright objects such as M42, the nebula Orion.
Sowhat my bags of these two great stars, globular clusters, both of which have seemed surprising at x80 magnification? Both are globular clusters. M92 has been alternately known as NGC 6341, discovered in 1777 by Johann Elert, and Bode has an apparent magnitude of 6.4, making it one of the most prominent globular clusters. Charles Messier independently rediscovered and cataloged it on March 18, 1781 It is 26,700 light-years away in our galaxy alone, such as M13 in the constellationHercules.
M92 is visible to the naked eye under very good and a feather in the cap and through a telescope or binoculars. Has a mass of only about 330,000, and an angular size of 14 arc minutes, it's amazing when you close on the central regions of the Milky Way at a staggeringt 112 km / sec!
More or M92, which is excellent with the 'Great globular cluster in Hercules, M13, or otherwise known as NGC6205? E ', a similar distance of about 25 100 light yearsan apparent magnitude of 5.8 and an angular size of 20 arc minutes. It 'was discovered by Edmond Halley in 1714 and is one of the best known globular clusters in the sky of the northern hemisphere. M13 contains several 100,000 stars, and in 1974 he became a target for one of the first radio messages to any intelligent extraterrestrial races, sent by the great Arecibo radio telescope.
Both M13 and M92 are gems in the night sky in the north, and summer is the time to startmake the best of them!
