Farnham Astronomical Society » John Catlyn

North America Nebula (NGC 7000) imaged by John Catlyn

pcburns — Mon, 17 Aug 2009 10:37:50 +0000

The North America nebula (NGC 7000) is a diffuse Nebula in the constellation of Cygnus. It covers an area of the sky about four times the size of the full moon, but having very low surface brightness is low so normally it cannot be seen with the unaided eye.

Lookup the North America Nebula on SEDS

Comet Machholz imaged by John Catlyn

pcburns — Mon, 17 Aug 2009 10:30:36 +0000

Comet Machholz, formally designated C/2004 Q2 is a long-period comet discovered in August 2004 by Donald Machholz (his 10th comet, found visually, with his 6 inch reflector). In January 2005 it reached naked eye brightness. Its perihelion was farther from the Sun than the Earth’s orbit. The comet will return, but you will have a long wait. Its extremely large orbit will not bring it back to the inner Solar System for another 112,000 years. Don’t wait up for it!

M82 Imaged by John Catlyn

pcburns — Mon, 17 Aug 2009 09:45:24 +0000

M82 (also known as NGC 3034) is an iregular galaxy in the constellation of Ursa major – though classified as irregular, though probably a distorted disk galaxy. The M81group of galaxies is one of the nearest to our Local Group, being only some 12 million light-years distant.

M82 is under the gravitational influence of its its larger neighbour M81. Tidal forces caused by gravity are deforming this galaxy, a process that started about 100 million years ago. These tidal forces have caused starburst activity in M82 – star formation has to increase 10 fold compared with “normal” galaxies.

Lookup M82 on SEDS

The Ring Nebula (M57) Imaged by John Catlyn

pcburns — Mon, 17 Aug 2009 09:20:30 +0000

M57 is a planetary nebula in the constellation of Lyra and is visible in small telescopes.

Planetary nebulae such as M57 are formed when a low or medium mass star (such as the Sun) exhaust its hydrogen in the stellar core. The structure of the star changes so it can achieve a new equilibrium condition in which it can continue to burn heavier elements. When the supply of hydrogen at the core is exhausted, radiative energy is unable to support the weight of the star above it and it begins to collapse, converting gravitational energy into thermal energy. As the star collapses and the temperature of the core rises, the fusion of Hydrogen into Helium occurs in the shell. When the core temperature reaches about 100 million degress fusion of Helium into Carbon begins. As the core contracts, the outer regions of the star begin to expand and the star becomes a red giant. A strong wind begins to blow from the star’s surface and, in the course of the star’s red giant life, carries away most of the hydrogen envelope surrounding the star’s central core. The envelope of ejected matter becomes a planetary nebula.

Illuminated by their central stars Planetary nebulae can display beautiful structures: some are spherical or helical, others have bipolar shapes, and others are rather irregularly shaped. Within a few tens of thousands of years the matter forming a planetary nebula will intermingle with the interstellar medium and disperse.

More massive stars will meet a far more cataclysmic end – a supernova.

Lookup M57 on SEDS

M42 Imaged by John Catlyn

pcburns — Mon, 17 Aug 2009 08:01:20 +0000

M42 (NGC 1976) is an an emission and reflection nebula, with Open Star Cluster, in Orion. It is also a starforming nebula.

Lookup M42 on SEDS

The Dumbbell Nebula (M27) Imaged by John Catlyn

pcburns — Mon, 17 Aug 2009 07:57:24 +0000

This planetary nebula in the constellation of Vulpecula is is perhaps the finest planetary nebula in the sky and can be viewed in a small telescope or binoclualrs.

Lookup M27 on SEDS

Brocchi’s Cluster Imaged by John Catlyn

pcburns — Mon, 17 Aug 2009 07:52:39 +0000

Brocchi’s Cluster is an Open Cluster Collinder 399 in the constellation of Vulpecula. Its appearance suggests it might be an asterism only.

Lookup Brocchi’s Cluster on SEDS

Comet Holmes by John Catlyn

pcburns — Mon, 17 Aug 2009 07:43:28 +0000

Comet Holmes (17P/Holmes) is a periodic comet which was discovered in 1892 by the British amateur astronomer Edwin Holmes. Although normally a very faint object, during its 2007 return when it unexepcedly brightened by a factor of approximately half a million and became visible to the naked eye. This was the largest known outburst by a comet. It also briefly became the largest object in the solar system, as its coma expanded to a diameter greater than that of the Sun.

The images below were taken over three days from October 30 2007 to Nov 4 2007. All images are with a 10 second exposure.

Comet Holmes imaged on October 30 2007

Comet Holmes imaged on November 1 2007

: Comet Holmes imaged on November 4 2007