"Comet Lemmon has a beautiful tail with lovely fine structure," says Phil Hart of Lake Eppalock, Victoria, Australia, who photographed it on Feb. 17th.
The comet is now slightly closer to the sun than Earth. Solar heating has turned it into a binocular object (magnitude +5.5 to +6) barely visible to the human eye, but dazzling through backyard telescopes, as shown in Hart's photo above.
Comet Lemmon's verdant color comes from two of the gases boiling off its nucleus: cyanogen (CN: a poisonous gas found in many comets) and diatomic carbon (C2). Both substances glow green when illuminated by sunlight in the near-vacuum of space.
The combination of its colorful atmosphere and filamentary tail make this comet visually striking. Ultimately, Comet Pan-STARRS and especially Comet ISON could surpass it, but for now the most beautiful comet in the solar system appears to be a green Lemmon. More about Comet Lemmon: 3D orbit, ephemeris, light curves.
In Early February
Glowing much brighter than expected, Comet Lemmon (C/2012 F6) is gliding through the skies of the southern hemisphere about 92 million miles (0.99 AU) from Earth. Amateur astronomer Rolf Wahl Olsen sends this picture from his backyard in Auckland, New Zealand:
"I took this image of Comet Lemmon on the 28th of January," says Olsen. "It has become quite bright now and has also grown a beautiful tail." Discovered on March 23rd 2012 by the Mount Lemmon survey in Arizona, Comet Lemmon is on an elliptical orbit with a period of almost 11,000 years. This is its first visit to the inner solar system in a very long time. The comet is brightening as it approaches the sun; light curves suggest that it will reach 2nd or 3rd magnitude, similar to the stars in the Big Dipper, in late March when it approaches the sun at about the same distance as Venus (0.7 AU).
At the moment, the comet is glowing like a 7th magnitude star, just below the limit of naked-eye visibility. To capture the faint details of the comet's filamentary tail, Olsen used a 10-inch telescope, a sensitive CCD camera, and an exposure time of 1 hour 17 minutes. Complete photo details are given here. Lemmon's green color comes from the gases that make up its coma. Jets spewing from the comet's nucleus contain cyanogen (CN: a poisonous gas found in many comets) and diatomic carbon (C2). Both substances glow green when illuminated by sunlight in the near-vacuum of space. Northern hemisphere observers will get their first good look at the comet in early April; until then it is a target exclusively for astronomers in the southern hemisphere.
In Late January
2013 could be the Year of the Comet. Comet Pan-STARRS is set to become a naked eye object in march, followed by possibly-Great Comet ISON in November. Now we must add to that list green Comet Lemmon (C/2012 F6). "Comet Lemmon is putting on a great show for us down in the southern hemisphere," reports John Drummond, who sends this picture from Gisborne, New Zealand.
"I took the picture on Jan. 23rd using a 41 cm (16 in) Meade reflector," says Drummond. "It is a stack of twenty 1 minute exposures." That much time was required for a good view of the comet's approximately 7th-magnitude coma ("coma"=cloud of gas surrounding the comet's nucleus). Lemmon's green color comes from the gases that make up its coma. Jets spewing from the comet's nucleus contain cyanogen (CN: a poisonous gas found in many comets) and diatomic carbon (C2). Both substances glow green when illuminated by sunlight in the near-vacuum of space.
Discovered on March 23rd 2012 by the Mount Lemmon survey in Arizona, Comet Lemmon is on an elliptical orbit with a period of almost 11,000 years. This is its first visit to the inner solar system in a very long time. The comet is brightening as it approaches the sun; light curves suggest that it will reach 2nd or 3rd magnitude, similar to the stars in the Big Dipper, in late March when it approaches the sun at about the same distance as Venus (0.7 AU). Northern hemisphere observers will get their first good look at the comet in early April; until then it is a target exclusively for astronomers in the southern hemisphere. - Space Weather.
Original post @ http://thecelestialconvergence.blogspot.hk/2013/02/fire-in-sky-2013-year-of-comet-comet_22.html
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