Amateur Astronomers See Comet ISON   
       
   Sept. 24, 2013:  Anticipation is building as Comet ISON approaches the sun for   
   a close encounter on Thanksgiving Day (Nov. 28). No one knows if the blast of   
   solar heating ISON receives will turn it into one of the finest comets in   
   years--or destroy the icy visitor from the outer solar system.   
       
   Astronomer Carey Lisse, the head of NASA's Comet ISON Observing Campaign,   
   hopes that "every telescope on Earth will be trained on the comet in October   
   and November."  He may get his wish. As September comes to an end, amateur   
   astronomers around the world are already monitoring the comet.   
       
   "Comet ISON is approaching Mars in the pre-dawn sky," explains Lisse. "It is   
   invisible to the naked eye, but within reach of backyard telescopes."   
       
   http://www.youtube.com/watch?v=E6Yd-TiNiyU   
       
   A new ScienceCast video explores the improving visibility of Comet ISON. Play   
   it   
       
   "I photographed Comet ISON on Sept. 15th using my 4-inch refractor," reports   
   astrophotographer Pete Lawrence of Selsey UK.  "The comet's tail is nicely on   
   view even through this relatively small instrument." image   
       
   In Aquadilla, Puerto Rico, astronomer Efrain Morales Rivera saw the comet on   
   Sept. 14th "rising above the canopy of the rain forest just minutes before   
   sunrise. I used a 12-inch telescope," he says. image   
       
   Auroras Underfoot (signup)In mid-September, the approaching comet was glowing   
   like a star of 14th magnitude.  That's dimmer than some forecasters expected.   
       
   "Certainly we would love it to be a couple of magnitudes brighter right now,"   
   says researcher Karl Battams of the Naval Research Lab in Washington,   
   D.C.,"but it's doing just fine. I'd say it's still on course to become a very   
   eye-catching object."   
       
   Battams is especially optimistic about NASA's twin STEREO probes and the   
   NASA/ESA Solar and Heliospheric Observatory.  Those three spacecraft are   
   equipped with coronagraphs--devices which cover the blinding disk of the sun   
   to produce an artificial eclipse.  The coronagraphs will be able to see ISON   
   at its brightest when it is making its closest approach to the sun on   
   Thanksgiving.   
       
   Comet ISON Light Curve   
   The light curve of Comet ISON. The solid line traces the predicted brightness   
   of the comet; red dots are actual observations. These data were compiled by   
   Matthew Knight of the Lowell Observatory on Sept. 20, 2013. More   
   If ISON survives its brush with solar fire, sky watchers on Earth might get an   
   eye-full as well.   
       
   Based on the latest images, internationally known comet expert John Bortle   
   says "ISON appears likely to survive the in-bound leg of its journey all the   
   way to the Sun. It will probably brighten more slowly than all the early hype   
   led the public to believe. Nevertheless, Comet ISON should very briefly become   
   exceptionally bright, at least rivaling the planet Venus in the hours   
   preceding its closest approach to the sun."   
       
   After Thanksgiving (Nov 28th), Comet ISON will emerge from the sun's glare   
   well-positioned for observers in the northern hemisphere. The comet's tail   
   will likely be visible to the naked-eye in both the morning and evening sky   
   throughout December 2013.   
       
   Comet ISON orbit   
   For observing tips and more information, visit the home page of NASA's Comet   
   ISON Observing Campaign. GoA useful point of comparison is  Comet Lovejoy,   
   which put on a grand show after it brushed the sun in 2011.  People in the   
   southern hemisphere still remember the comet's tail stretching halfway across   
   the night sky. Judging from the brightness of Comet ISON, Matthew Knight of   
   the Lowell Observatory believes that "ISON is likely a few times bigger than   
   Lovejoy was, so I am optimistic that Comet ISON will become an impressive   
   sungrazer."   
       
   Because this is Comet ISON's first visit to the inner solar system, no one can   
   say for sure what will happen. Comets are unpredictable, capable of fizzling   
   at the last minute even after months of promising activity.   
       
   Battams, who has been "burned" before by sungrazing comets, cautions that "at   
   no point in the next couple of months are we going to know if Comet ISON will   
   survive or not until we actually observe it with our own eyes."   
       
   "Observations from amateur astronomers are really valuable pieces of the   
   puzzle for us," adds Battams. "They help us to see how the comet is evolving."   
       
   The NASA Comet ISON Observing Campaign aims to get as many eyes on ISON as   
   possible.  To learn how you can help, visit http://isoncampaign.org.   
       
   Credits:   
       
    Author: Dr. Tony Phillips | Production editor: Dr. Tony Phillips | Credit:   
   Science@NASA   
       
       
   Regards,   
       
   Roger   
      
   --- D'Bridge 3.94   
    * Origin: NCS BBS - Houma, LoUiSiAna (1:3828/7)