M31 The Andromeda Galaxy



M31 and M32 in the Constellation of Andromeda

Took my first astro-photo of an object outside the Milkyway. The night I took this was a bit cloudy and this image is the combination of only four light frames (4x20 secs). Consquently, I am quite pleased that I was able to tease out some detail of the galaxy core showing hints of the spiral arms and dust lanes.
You can also see the gravitationly linked elliptical galaxy M 32 which is part of the Andromeda Group our nearest galactic neighbours.

Andromeda is the largest galaxy of the Local Group, which consists of the Andromeda Galaxy, the Milky Way, the Triangulum Galaxy, and about 30 other smaller galaxies. Although the largest, Andromeda may not be the most massive, as recent findings suggest that the Milky Way contains more dark matter and may be the most massive in the grouping. The 2006 observations by the Spitzer Space Telescope revealed that M31 contains one trillion (10¹²) stars, at least twice more than the number of stars in our own galaxy, which is estimated to be c. 200–400 billion.

Andromeda is estimated to be 7.1×10¹¹ solar masses. In comparison a 2009 study estimated that the Milky Way and Andromeda are about equal in mass,^] while a 2006 study put the mass of the Milky Way at ~80% of the mass of Andromeda. The Andromeda Galaxy and the Milky Way are expected to collide in perhaps 4.5 billion years.

The Milky-Way

The Milky -Way as it runs through Cassiopeia
(Look for the Andromeda Galaxy clearly visible left of centre top)

After midnight when the street lights are turned off, the sky becomes transparent and the Milkyway stretches from horizon to horizon.  In late September the Milky-Way bisects the sky, with the constellation Cassiopeia directly overhead. The view from our garden is breath taking!
The image was taken using my Canon 400D EOS SLR with a 28mm lens, 4 photographs were shot in RAW each of 20 seconds duration at 800 ASA. The four light frames together with an equal number of dark frames were stacked using DeepSkyStacker. The resultant combined image was then manipulated using Canon Digital Professional, Photoshop and Neat Image software.

The Ring Nebula in Lyra

M57 The Ring Nebula (my photo)

Had "une belle nuit de l'astronomie dans le jardin". I photographed a number of astro treats through my refractor. The "seeing" was not brilliant as high level cloud was an intermittent problem.  The lack of light pollution thanks to Suffolk County Council turning off the street lights at midnight was a great help. Thank you SCC!

 

M57 The Ring Nebula ( Hubble photo)

M57 The Ring Nebula (my photo enlargement)

Planetary nebula nucleus (PNN)

The central PNN was discovered by Hungarian astronomer Jenő Gothard on September 1, 1886 from images taken at his observatory in Herény, near Szombathely (now part of Szombathely). Within the last two thousand years, the central star of the Ring Nebula has left the asymptotic giant branch after exhausting its supply of hydrogen fuel. Thus it no longer produces its energy through nuclear fusion and, in evolutionary terms, it is now becoming a compact white dwarf star.

The PNN now consists primarily of carbon and oxygen with a thin outer envelope composed of lighter elements. Its mass is about 0.61–0.62 solar mass, with a surface temperature of 125,000±5,000 K. Currently it is 200 times more luminous than the Sun, but its apparent magnitude is only +15.75.

M 57 is 0.7 kpc (2,300 light-years) from Earth. It has a visual magnitude of 8.8v and photographic magnitude of 9.7p. Photographically, over a period of 50 years, the rate of nebula expansion is roughly 1 arcsecond per century, which corresponds from spectroscopic observations to 20–30 km⁻¹). M 57 is illuminated by a central white dwarf or planetary nebula nucleus (PNN) of 15.75v visual magnitude, whose mass is approximately 1.2 MΘ (in solar masses.)

All the interior parts of this nebula have a blue-green tinge that is caused by the doubly ionized oxygen emission lines at 495.7 and 500.7 nm. These observed so-called "forbidden lines" occur only in conditions of very low density containing a few atoms per cubic centimetre. In the outer region of the ring, part of the reddish hue is caused by hydrogen emission at 656.3 nm, forming part of the Balmer series of lines. Forbidden lines of ionized nitrogen or [N II] contributes to the reddishness at 654.8 and 658.3 nm.

A Duck, a Chicken, a Cat and a Spider

"Turned out nice then"

"A Duck, a Chicken and a Cat sat looking at the sky

When a Spider enquired politely have you seen a fly?

You see I'm rather hungry and I haven't had my tea

Could you spare a mite or a great big tick

Would you donate a juicy flea"

Returned to the Cabine after a summer break and continued my experiments with digital picture making, printing and framing. Hope Jasmine likes the picture and gets her Dad to hang it in her Wendy House.

Feeling pleased with myself as yesterday I converted an old webcam for use as an astro-imaging camera. It appears to work but have yet to test it at night attached to my large telescope. If it works, I should be able to use it to photograph Jupiter which is currently visible high above the southern horizon by the early hours of the morning.