ALPO COMET NEWS FOR JULY 2016
2016-July-3
June was a slow month for comet watchers. C/2013 X1 (PANSTARRS) was bright enough at 6th magnitude but spent much of June at far southern declinations. This month, X1 is slowly returning to the northern sky though it may still be too far south for many northern observers. Unfortunately, no other comets are expected to be brighter than 10th magnitude this month.
The Comet Section image gallery ( https://alpo-astronomy.org/gallery/main.php?g2_itemId=4491 ) is only a few images shy of 2000 images! Please take a look at our extensive collection of comet images. If you have images that are missing from the archive, please submit them for inclusion by contacting me (chergen @ lpl . arizona . edu). The Comet Section would like all types of comet submissions (CCD images, photographic images, drawings, magnitude estimates, textual descriptions) for all comets, past and present. CCD data can be sent as FITS and/or GIF, JPEG, PNG images.
Evening Comets
C/2013 X1 (PANSTARRS) [Perihelion on 2016-Apr-20 at 1.31 AU]
C/2013 X1 (PANSTARRS) is now well past its April perihelion and also its closest approach to Earth on June 21. It peaked at magnitude 6.0 to 6.5 as it passed within 0.64 AU of Earth. The comet has since faded to magnitude 7.0.
During most of June it was located far south. This month X1 is moving slowly north in the evening sky as it travels through Ara (Jul 1-3), Norma (3-8), Lupus (8-16), and Centaurus (16-31). Its declination will increase from -48° to -32° as its elongation drops from 148° to 96°. At the beginning of the month, PANSTARRS will be 1.68 AU from the Sun and 0.73 AU from the Earth. By the end of the month, the distances will increase to 1.98 and 1.60 AU from the Sun and Earth, respectively. As a result of these increases, the comet will fade from 7th to 9th magnitude.
New Discoveries
Since the last Comet Section News posting, only one comet was discovered.
C/2016 M1 (PANSTARRS) was discovered on June 22 with the 1.8-m Pan-STARRS1 telescope on Maui. C/2016 M1 is a long-period comet and was 7.7 AU from the Sun at discovery. Its perihelion won’t occur till August of 2018 at a much closer heliocentric distance of 2.2 AU. Though currently 18th magnitude, it may get as bright as 10th magnitude during the summer of 2018. Northern CCD observers will be able to follow the comet before perihelion when its 91° inclination orbit takes it south and makes it well placed for southern CCD observers post-perihelion.
As always, the Comet Section is happy to receive all comet observations, whether images, drawings or magnitude estimates.
- Carl Hergenrother (ALPO Comet Section Coordinator)
