Farnham Astronomical Society » Chris Thayer

M65 and M66 Imaged by Chris Thayer

pcburns — Fri, 14 May 2010 12:28:53 +0000

M65 (NGC 3623) and M66 (NGC 3627) are two of the galaxies that make up the Leo Triplet (also known as the M66 Group of Galaxies). As its name suggests the Leo Triplet can be found in the constellation of Leo. Charles Messier is generally assumed to have discovered these galaxies but it is possible that they were first discovered by Pierre Mechain.

M65 (left) is a type Sa spiral galaxy, and M66 (right) is an Sb spiral. Both galaxies are approximately 33Mly away and are separated by an estimated 200,000 light years. The two galaxies are similar in size. The western arm of M66 is warped with respect to the plane of the galaxy and this is thought to be as a result of a past encounter with another galaxy in the Leo Triplet, probably NGC3628. As a result, Hamilton Arp included M66 in his Atlas of Perculiar Galaxies (M66 appears as entry 16, the entire group appears as entry 317). It is thought that M66 lost many thousands of solar masses in this encounter.

In 10×50 binoculars M65 and M66 can be seen as faint nebulous spots. In a small telescope both M65 and M66 remain in the same field of view with M65 appearing elongated.

M65 and M66 imaged by Chris Thayer

Imaged using an ED80 mounted on an LX200 and a Mead DSI3

Images of Lunar Features by Chris Thayer

pcburns — Sat, 24 Apr 2010 17:10:21 +0000

Chris thayer took the following excellent images using his 10″ LX200 amd meade DSI2

: Archimedes, Aristillus and Autolycus by Chris Thayer

: Eudoxus crater by Chris Thayer

: Copernicus Crater by Chris Thayer

Copernicus Imaged by Chris Thayer

pcburns — Fri, 30 Oct 2009 07:56:55 +0000

Copernicus, a prominent lunar impact crater situated in Oceanus Procellarum , is named after the astronomer Nicolaus Copernicus (1473 – 1543). It is over 90km in diameter and almost 4km deep. Its ‘rays’ spread up to 800Km across the surrounding mare. This ‘young’ crater is estimated to be about 800 million years old.

: Copernicus – click to enlarge

Pelican Nebula Imaged by Chris Thayer

pcburns — Wed, 14 Oct 2009 06:42:00 +0000

The Pelican Nebula (also known as IC5070) is a large emission nebula in the constellation Cygnus. It is separated from its larger neighbour, the North America Nebula, by a molecular cloud filled with dark dust.

: Pelican Nebula – click to enlarge

Imaged using an ED80 and DSI3mono. 9 x 5.5 min subframes using a Ha filter. The image was guided with a 10″ LX200GPS at F 6.3 and DSI3c.

Swan Nebula (M17) Imaged by Chris Thayer

pcburns — Wed, 23 Sep 2009 07:27:18 +0000

M17, the Swan Nebula (also designated NGC 6618) is an emission nebula (HII region) in the constellation of Sagittarius. The radiation of a cluster of stars embedded in nebula is exciting the gass and causing the emission. It is roughly 40 light years in diameter and is over 5,000 ly away. Its mass is estimated to be 800 solar masses.

It was discovered by Philippe Loys de Ceseaux in 1745 and catalogued by Charles Messier in 1764.

Lookup M17 on SEDS

: Swan Nebula – click to enlarge

Imaged using an ED80 and DSI3 mono CCD, guided using a Meade DSI3c / LX200GPS 10″

Exposure details: 12 frames x 30sec using Ha Filter

Elephant’s Trunk Nebula (IC1396) Imaged by Chris Thayer

pcburns — Fri, 28 Aug 2009 06:45:54 +0000

IC 1396 is an emission nebula in the constellation of Cephus. It is a mix of gas and dust clouds; the gas is energised by a bright, central star. This region spannsing over three degrees on the sky and yet is nearly 3,000 light-years away. The winding Elephant’s Trunk nebula seen here is only a small part of IC1396.

Lookup IC1396 on SEDS

: Elephant’s Trunk Nebula

Images using an ED80 and Meade DSI3mono and guided using an LX200GPS.

Exposure: 11 frames of 4min using an Ha Filter

M42 Imaged by Chris Thayer

pcburns — Mon, 24 Aug 2009 17:00:37 +0000

The Orion Nebula, M42 (also designated NGC 1976) is a diffuse nebula (an HII region) situated south of Orion’s Belt and is one of the brightest nebulae, and is visible to the naked eye. It is approximately1,344±20 light years away and is the closest region of massive star formation to Earth. It is estimated to be 24 light years across. The nebula surrounds and is excited by the four young stars of the Trapezium. The main part of the nebula is separated from a smaller part (known as M43) by a dark absorbing region called the Fish’s Mouth.

HII regions are interstellar gas clouds consiting of ionized hydrogen and are normally associated with regions of active star formation. UV flux from hot young stars ionizes surrounding gas creating complex but beautiful nebulae such as M42. In gasseous galaxies, HII regions trace locations where vigorous starbust formation is taking place.

Lookup M42 on SEDS

M42 imaged by Chris Thayer - click to enlarge

This image was taken using an ED 80 and Mead DSI2c, and guided using a DSIc and LX200 GPS 10″ at f6.3.

Globular Cluster M13 Imaged by Chris Thayer

pcburns — Mon, 24 Aug 2009 16:40:52 +0000

M13, the Great Globular cluster in Hercules (also designated NGC 6205) is easily the best known globular cluster in the Northern celestial hemisphere. Globular clusters are spherical compact gravitationally bound clusters of stars. There are about 160 globular clusters in our Galaxy and they contain some of its oldest stars – their compactness helps them to survive against disruption by external gravitational perturbations. These clusters are distributed throughout the visible halo of our Galaxy, filling a roughly spherical volume which rotates slowly compared with the disc. We see no evidence of globular-cluster-sized star clusters forming in our Galaxy. This suggests that the conditions that led to the formation of globular clusters in our Galaxy were quite different from the current conditions.

Lookup M13 on SEDS

: Globular Cluster M13 by Chris Thayer – click to enlarge

Image taken with a Mead LX200 GPS 10″ at f 6.3 and Mead DSI3c. This is an unguided image comprising 50 stacked images of 5.7 sec frames each.

Crescent Nebula Imaged by Chris Thayer

pcburns — Mon, 24 Aug 2009 16:19:49 +0000

The Crescent Nebula (also designated NGC 6888 and Caldwell 27 on Patrick Moore’s Caldwell catalogue) is an emission nebula in the constellation of Cygnus. It was formed by fast stellar winds from the Wolf-Rayet star WR 136 (HD 192163) colliding with and energizing the slower moving wind (ejected by the star when it became a red giant around 400,000 years ago) creating a shell and two shock waves. One shock wave is moving outward and the other inward; the inward moving shock wave energises the stellar wind to temperatures where X-rays are emitted.

Wolf-Rayet stars are hot massive stars (more than 25 solar masses) which are undegoing heavy mass loss. They are characterised by an extraordinary spectrum consisting of very wide emission bands as well as absorption lines in the violet region. These lead astronomers to conclude that these stars are surrounded by rapidly expanding shells of gas. Wolf-Rayet stars are classified as irregular variable stars, and are sometimes also called W stars. They are extremely rare, reflecting their short lifespan.

Lookup NGC 6888 on SEDS

Crescent nebula by Chris Thayer - click to expand

Imaged using an ED 80 and Mead DSI 3mono and guided with LX200 GPS at f 6.3 with Mead DSI3c. Exposure: 9 frames x 4min (Hydrogen alpha)

The Eagle Nebula (M16) Imaged by Chris Thayer

pcburns — Sun, 23 Aug 2009 14:43:23 +0000

The Eagle Nebula, M16 is a region of star formation in the constellation Serpens – it has already created an open cluster of stars (the cluster is designated NGC 6611 and the nebula is IC 4703). It was discovered by Jean-Philippe de Cheseaux in 1745-4.

The Eagle Nebula features in one of the most iconic Hubble Space telescope images – the Pillars of Creation, which shows pillars of star-forming gas and dust within the nebula.

Stars form from a clouds of cool, dense gas. A disturbance, maybe the shock wave from an exploding star or maybe gravitational tidal effects of nearby objects causes a gravitational imbalance and the cloud to contract. Under its own gravitational force, the cloud continues to contract into a smaller and smaller volume and the pressure builds up in the core as the density increases. If the temperature increases so that the energy of the colliding hydrogen nuclei overcomes their natural repulsion. Nuclear fusion begins, and a star is born. Young stars are usually bright X-ray sources. However, observations by Chandra has found very few X-ray sources in the pillars. This would suggest that the pillars, and the few stars forming inside them are the last vestiges of star formation in the nabula which peaked several million years earlier. This differs from other nebulae where Chandra has detected very active star forming regions

The dark hydrogen clouds at the top of the fingers are resisting erosion – the hydrogen gas and dust have withstood the ultraviolet light from the hot, young stars longer than the surrounding gas. Research by the Dublin Institute of Advanced Studies suggests that shadows hold the key to how giant star-forming structures like these form. The Dublin group suggests that partially-shadowed clumps of gas creep towards darker areas, causing pile-ups behind dense knots of gas and dust that screen the intense ultraviolet light emitted by the stars.

Lookup M16 on SEDS

: The Eagle Nebula (M16) by Chris Thayer – Click to enlarge

Image taken with an ED80 and Mead DSI3 mono CCD and guided with LX200 GPS at f6.3 and DSI 3c. Exposure: 21 frames x 4mins each in H-alpha