Popular Astronomy

April 2015

Five section members sent in 9 images and 5 drawings during April.

Alan Clitherow, Planetary Section Director, took this image of M86 with his MN 190 P telescope and QHY100SC camera.

Alan was experimenting with an off axis guider and this image is the result of stacking around 5 six minute exposures. 

M86 is an eliptical galaxy in the constellation of Virgo, lying at the heart of the Virgo galaxy cluster.  There are a lot of galaxies in this image;  above M86 is another eliptical galaxy, M84:  to the left and right are edge - on galaxies NGC4402 and NGC4388.  Below M86 are two galaxies near the bottom of the image, the one on the right is NGS4438, and on the left is  NGC 4435; together they are known as the "Eyes galaxies" or Arp 120.

M86 has a magnitude of 9.8, and is about 52 million light years from the Earth.  It is notable for having a highly blue - shifted spectrum, since it is moving toward the centre of the Virgo cluster from the side opposite to us at a rate of about 250 km/sec.                


Dale Holt, using his 505mm f 3.5 Newtonian telescope with a cooled Watec120N video camera, sketched Arp 286, located in         the constellation of Virgo.  This is actually three galaxies, NGC5566, (biggest), NGC5569 (smallest, below left) and NGC5560 (most distorted, bottom right). 

In colour images NGC5566 is decidedly yellow, NGC5569 a pronounced blue, whereas NGC5560 is multicoloured.      

Ian Papworth, Membership Secretary and SPA Council Member, sent in 4 images.  Ian used a Celestron 6SE f6.3 telescope and an ASI 120MM camera, plus colour filters for the M57 image.  On the left below is globular cluster M3, in the constellation of Canes Venatici.  On the right, M57, the "Ring" planetary nebula in the constellation of Lyra.  M3 has an apparent magnitude of 6.2, so it is a borderline naked eye object even with the most favourable observing conditions.  It contains an untypically large population of variable stars.  M57 is 1.5 x 1 arcminutes in angular size and is about 2,300 light years from the Earth.


Ian's next two images were of spiral galaxies.  On the left below is M101, the "Pinwheel" galaxy in the constellation of Ursa Major, and on the right M94 in the constellation of Canes Venatici.  M101 is about 170,000 light years across and contains about 100 billion solar masses worth of stars.  M94 has an inner and outer ring,; the former is a starburst region, where star formation is being driven by the inner bar -like structure sending gas into the ring.


Below is a second image of M94;  Ian sent this both as a "positive" and a "negative" to help show the fine detail captured.


   Michael Kinns sent in 4 drawings, all of galaxies, using a 200mm f6 Orion Optics Newtonian telescope.   Below left is M105,  an eliptical galaxy in the constalletion of Leo:  also in this drawing is eliptical galaxy NGC3384.  Both are members of the  M96 group of galaxies, which also includes M95.  On the right is M49, another eliptical galaxy in the constallation of Virgo.  The nucleus of M49 emits X rays; it is likely that the supermassive black hole responsible is around 565 million solar masses, whereas the black hole inside M105 is "only" around 1.5 - 2 million solar masses

               Here Michael has sketched edge - on galaxy NGC4565 (left) and NGC4725 (right) both in the constellation of Coma Berenices.  NGC4565 is also known as the needle galaxy or Caldwell 38.  It is a giant spiral and if it were face on would be truly spectacular.  NGC4725 is an intermediate barred spiral Seyfert galaxy; it has an active nucleus indicative of the presence of a supermassive black hole.


  Steve Norrie, observing from Fife,  imaged four galaxies, all to be found in the Messier catalogue.  Clockwise from below left they are:  M106, M99, M61, and M64.  Steve used a Skywatcher EDR80 refractor and a modified Canon 600D DSLR.




M106 is a spiral galaxy located in the constellation of Canes Venatici.  Classified as a Seyfert II galaxy, the production of X rays and unusual emission lines in its spectrum indicates an active supermassive black hole at the centre of M106.

M99, located in the constellation of Coma Berenices, is not classified as a starburst galaxy but it does have star formation activity about three times that of  other, similar galaxies.

M61 is a barred spiral galaxy in the Virgo cluster.   This galaxy is classified as a starburst type,  and its supermassive black hole is thought to be around 5 million solar masses.  

M64 is the well - known "Black Eye" galaxy in Coma Berenices;  its inner disc contains the dust lanes responsible for its appearance.  The outer disc is of similar mass to the inner one, but rotates in the opposite direction.

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