Popular Astronomy

October 2017

This month, four section members produced a total of twenty images. 

David Davies imaged Collinder 399, right, an asterism  of ten stars of between magnitude 5 and 7 which lies in the constellation of  Vulpecula.  This asterism was recorded in the 10th century by the Persian astronomer Al Sufi, and is also known as Brocchi's cluster and for obvious reasons the Coathanger.

This is a line of sight phenomenon not a true cluster: the ten stars lie at considerably different distances from the Earth, between about 240 light years for the nearest (5 Vul) and 2240 light years for the most distant (HD183261).

Observing from Cambridge, David used an APM 107 APO refractor and QSI 583 mono camera plus red, green and blue filters.

Steve Cooke sent in a total of ten images of a wide variety of deep sky objects, the first four clockwise from below left are globular clusters M15 in Hercules, M2 in Aquarius, and open clusters M45 the Pleiades in Taurus and M35 in Gemini.   The smaller, more compact open cluster at the top right of the M35 image is NGC2158.                                                                                                                                                                                           



                                                                                                                                                              Steve's next four images are, from below left. open cluster M11, the Wild Duck cluster in Scutum;  B33, the Horsehead dark nebula within emission nebula IC434 in Orion;  then planetary nebulae M27, the Dumbbell nebula in Vulpecula and M57, the Ring nebula in Lyra.                                                        



Steve's final two images are below left, M42 emission/reflection nebula in the constellation of Orion, and right M33, the Pinwheel spiral galaxy in Triangulum.                                                                                        


Steve, observing from Brixton, used a Skywatcher 200P Newtonian reflector and Canon 1000D DSLR for the above images.                                                                                                     

Alan Clitherow, SPA Planetary section director, made this image (right) of emission/reflection nebula IC63 in the constellation of Cassiopeia.  The bright star in the image is gamma Cass. 

This is one region of the nebulosity surrounding gamma Cass, and is slightly closer to the star than the other part, not in this image, which is predominantly a reflection nebula labelled IC59.  Gamma Cass shines at apparent magnitude 2;  the nebulosity is much fainter at magnitude 10.

Alan, observing from Fife, used a MN 190P Maksutov - Newtonian telescope and Canon EOS 600D astro - modified DSLR for this H alpha/ RGB image.                                                                         


Steve Norrie, also observing from Fife, sent in eight images to the section.  For these images Steve employed an ES 127mm APO refractor working at f5, and a StarlightXpress Trius 694 mono camera plus red, green, blue and narrow band filters.

Steve's first four images are below:  in a clockwise direction are two emission nebulae:  IC1318, in the constellation of Cygnus and IC1848, the Soul nebula in Cassiopeia (both of the latter in the Hubble palette),  then NGC1499 the California emission nebula in Perseus and IC434 (plus B33) the Horsehead nebula in Orion alredy mentioned above.  The last two images are H alpha/green /blue plus H alpha luminance.   

IC1318 appears to surround second magnitude star Sadr or gamma Cyni, lying at the centre of the cross of stars defining the constellation.  In reality Sadr is twice as close to the Earth as the nebulosity.                                                                                                                                                                                                                                                                             




                                                                                                                                                                                      Steve's last four images are IC63, reflection/emission nebula in the constellation of Cassiopeia, (H alpha (monochrome image) described above;  M33 spiral galaxy in Triangulum;  NGC896 the Heart emission nebula in Cassiopeia and NGC2174 emission nebula in Orion (H alpha mono image).




                                                                               Dave Finnigan          

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