Popular Astronomy

October 2014

This month, Dale Holt sent in three sketches.  The first (below left) is of Abell 70, a planetary nebula in the constellation of Aquila.  This PN is between 13,500 and 17,500 light years away from the Earth.  The central star is actually a binary, one component being a white dwarf, the other a barium star, which is a giant star, spectral class G-K formed by mass transter from its companion.  The background galaxy just at the edge of the ring is named PMN J2033=0656.                                                                              Dale's second sketch (below) is of globular cluster M2, also in Aquila.  It is around 37,500 light years from the Earth, and is one of the biggest known, being 175 light years across.  It is also very old, of the order of 13 billion years, making it one of the oldest orbiting our galaxy.                    

                                                                                                                                                                                                                                                                                                                                                                                                                                The third sketch is of a spiral galaxy NGC6956, which lies in the constellation of Delphinus.  It's angular dimensions are quite small, 1.8 x 1.5 arcminutes, and its magnitude is given as 12.3.  It is a barred spiral galaxy, class SBb                                                                                                                                                   


  Geoff Elston, Director of SPA Solar Section,  continued to send in his images taken whilst on holiday in Northumberland (see September report).  On the left we have M103 and on the right NGC457, both open clusters in the constellation of Cassiopeia; the latter is also known as the Owl cluster or the ET cluster. M103 is more distant from the Earth than most open clusters at around 9,000 light years.  NGC457 is a little closer to us at 7,900 light years.


   Also in Cassiopeia, below left, is open cluster NGC436, and on the right open cluster M52, which can be observed with binoculars;  it is a 5th magnitude cluster around 13 arcminutes in diameter                                               


                                                                                                                                                                                                                                                                                                                 Geoff's final image is of globular cluster M13 (left), in the constellation of Hercules.  This firm favourite with amateur astronomers was discovered by Sir Edmund Halley in 1714.  At magnitude 5.8, and with an angular diameter of 23 arcminutes, (it is actually 145 light years across) it can be seen with the naked eye when the sky is very clear and dark.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           

 Michael Kinns made two drawings of open clusters in the constellation of Cygnus.  M29 (below left) was discoverd by Charles Messier in 1764, NGC6819 (below right) was discovered by Caroline Herschel in 1784.


The following images and drawings were sent by new section members.

Graham Taylor imaged NGC2403, a galaxy in the constellation Camelopardalis (below left) 

This was captured using the Bradford remote telescope, a Celestron C14, working at f5.3, situated on Teneriffe, Canary Islands. The camera was an FLI Microline with a 1k x 1k pixel chip.

NGC 2403 is 8 million light years from the Earth, and is 50,000 light years across.  It was the first galaxy beyond our local group in which a Cepheid variable star was discovered (by Alan Sandage in 1968).                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       Below are drawings made by Graham Sparrow when he attanded the recent Autumn Kelling Heath Star Party.  Graham used a Celestron 8SE telescope, and graphite pencil on white cartridge paper, scanned into the computer and inverted.  Below left is globular cluster M13 in the constellation of Hercules, and on the right M15, a globular cluster in Pegasus.

                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            Graham also observed the M42 nebula in Orion (below left) and the Witches Broom nebula (below right) in Cygnus.  The latter is also known as NGC6960 and is the Western part of the Veil Nebula, a large supernova remnant thought to be between 5000 and 8000 years old.  It is around 1500 light years from the Earth.

2014.10 Witch's Broom G.Sparrow.jpg                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             

Jonathan Shinn sent in three images, taken with an unmodified Canon ED550D DSLR camera attached to a Skywatcher ED80 refractor, on a NEQ6 mount.   Below left is emission nebula NGC7000, the North America nebula;  and to the right is IC1396, a dark nebula known as the elephant's trunk.  At the bottom left is M31, the well known spiral galaxy in the constellation of Andromeda.


  Mike and Alison Wood sent in sketches of NGC7331, (below left) and NGC7465 (below Right) using a 20" Dobsonian reflector.  NGC7331 is a magnitude 10.4 spiral galaxy about 40,000 light years from the Earth.  It is in the constellation of Pegasus, and a number of fainter galaxies are visible in this sketch.  NGC7465 is a member of a group of galaxies also in Pegasus, rather faint at magnitdes around 12.5, of which galaxies NGC7461, 7463 and 7448 are drawn here.                                                                                                                                                      



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