This post is based on an article published on the NASA JPL Rosetta science blog.
Comet 67P/Churyumov-Gerasimenko is back! In fact, the comet has been in sight for Rosetta for many months, but since the end of last year it was not possible to observe it with telescopes on Earth because it was in solar conjunction.
But now the comet has been recovered by amateur astronomers Jean-Francois Soulier, Jean-Gabriel Bosch and Alain Maury, who observed it from Chile on 13 April 2015 at a magnitude of of 16.8. Congratulations to the observers!
Comet 67P/C-G imaged by amateur observers on April 13, 2015. Credit: A. Maury, J.-F. Soulier and J.-G. Bosch
Padma A. Yanamandra-Fisher, Rosetta Coordinator of the Amateur Observations for Comet 67P/Churyumov-Gerasimenko, would like to alert the amateur astronomer community that 67P/C-G has now been recovered post-solar conjunction and invite them to participate in the campaign to observe the comet from April to December 2015, as Rosetta accompanies the comet to its perihelion and outbound journey.
“Amateur and professional observers should start to observe, safely, and please post with all the necessary information,” says Padma. “Those who can record the data in FITS, please provide us with RAW uncompressed data files.”
Amateur astronomers will be able to make significant contributions to the campaign, especially in 2015, leading up to perihelion in August and beyond, when the comet will be at its brightest (September – November). They can contribute in many formats, ranging from imaging, spectroscopic and binocular observations to sketches.
Amateur astronomers who wish to join the campaign can register here and on the corresponding Facebook group. For additional information, read the article on the NASA JPL Rosetta page here or contact Padma Yanamandra-Fisher.
Discussion: 3 comments
Nice performance by A. Maury et al!
By the way, Alain, now 55, is discoverer of comet 115P/Maury in August 1985 (he was working as a photography scientist for POSS at Palomar Observatory at that time) and co-discoverer of non periodical comet C/1988 C1 Maury-Phinney. Alain Maury also discovered the Amor class asteroid (1986 RA) Taranis while at Palomar… and many more celestial objects. Asteroid 3780 bears his name. “Since 2003 (when he left the professional career), Maury and his wife Alejandra have operated their own observatory near San Pedro de Atacama in Northern Chile. There, they give tours introducing visitors to the night sky in order to finance their own research and further public interest in astronomy.” (See https://www.spaceobs.com/en/ ).
Alain Maury and Jean-François Soulier have been also imaging comet 67P from June last year at magnitude 20-21 with a 0.4-m RC f/8 telescope + CCD (See for example https://6888comete.free.fr/fr/image67PChuryumovGerasimenkoChile.htm ).
See also Jean-Gabriel Bosch (remotely operating the same telescope) blog at https://transitionsciel.blogspot.fr/
Keep up the good job guys!
Even though the dust jets look prominent in Rosetta’s close-in time exposures, the comet is still a faint fuzzball in the Big Scheme of Things. Wait a few months!
Here are two ground-based observations. One is the discovery photograph from 1969 and the other is an ESO image from 2003.
https://univ.smugmug.com/Rosetta-Philae-Mission/EarthBased-Observations/i-XwfGbMc/0/L/Comet_67P_Churyumov-Gerasimenko_node_full_image_2–discovery–neg–enh-L.jpg
https://univ.smugmug.com/Rosetta-Philae-Mission/EarthBased-Observations/i-ngHnGhX/0/L/CG-coma-scale2–apr-2003–ESO-VLT–enh–neg-L.jpg
Note that in both archival images there is a cross-wise component in the shape of the coma, which suggests that the Polar Dust jets were active at that time.
–Bill
Amazingly good work. I believe they have taken more pictures now. Can one estimate the sizes of the coma and tail?