Astronomy

CCD Imaging with a Starlight Xpress CCD

The following images were taken with a Starlight Xpress parallel port mono CCD camera attached to my 14" f5.2 reflector. Most of the images were multiple one minute or thirty second unguided exposures combined to give the total exposure. The images were taken before any PEC correction or autoguiding was used with the 14". At high declinations the drive gave me round star images for 1 minute exposures. At lower declinations 30s was about the maximum before drifting occurred. The 14" could be guided with an off-axis guider but aligning the object on the CCD and a guide star in the o/a guider was a nightmare!. Unless otherwise noted all the images were taken from my light polluted location, about three miles from the city centre of Liverpool, England.

 

	Globular cluster M2 in Aquarius. 5.5 minute exposure, 24th Oct 2003.		NGC6946 on the Cygnus - Cepheus border. An excellent object to study visually or imaged. This image a 12 minute exposure.
	Everyone's favourite galaxy! M51 in Canes Venatici, high overhead from northern latitudes in the springtime. This image an 8 minute exposure.		The famous spiral M101 in Ursa Major. This 25 minute exposure shows many intersesting details in this face-on spiral including dense knots of star forming regions within the spiral arms.
	M66 in Leo Major, 9 minute exposure.		M99, 23.5 minutes
	M64, the 'black-eye' galaxy in Coma Berenices, this 7 minute exposure shows some fine detail in the inner 'eye' of the galaxy		M63, the sunflower galaxy. 15 minute exposure
	M100, 11 minutes		M82 in Ursa Major. This was taken when I had interference in the CCD signal, hence the image is fairly poor quality.

 

	This image of M13 was taken with Eric Strach's SXL8 CCD in the summer of 1996. The 2 minute exposure gave a very fine image which resolves the cluster's core and has sharp, tiny star images.
	NGC 884, better known as one half of the double cluster was taken with a 6" reflector at f6 and a 5 minute exposure. Providing the image is not enlarged too much stars at this smaller image scale do not appear 'square' and the CCD is able to cover a much larger area of sky.
	Not a colour image unfortunately, but Beta Cygni (Albireo) still looks a beautiful double star in this image. The colours of the stars in this famous double are often described as golden yellow and blue - take a look on the next clear night.

 

Nebulae

	M1, one of my first targets with the CCD camera. M1 has many fascinating features including it's unique history. M1 is the remnant of a supernova observed in 1054 AD and contains a pulsar at it's heart seen close to the centre of this image (see Burnham's Celestial Handbook p1860). The complex filaments are still expanding outward at 1000 Km-s. 10 minute exposure.		The Owl nebula, M97. Observed and named so by Lord Rosse with the giant 72" telescope at Birr castle in Ireland. 5 min exposure.
	M57, the ring nebula, one of the best known objects in the sky. Details in the ring are easily recorded with quite short exposures, this one was 2 minutes. The central star, much sought after visually, can be seen on exposures as short as 5 seconds with the CCD.		Without a doubt the most famous and probably the most observed nebula in the skies. The great Orion nebula M42 spans an area too large to fit on the CCD coupled to the 14". This picture is a composite of 3 images carefully taken, calibrated and jigsawed together. Each image was exposed for just 15s.
	Hubble's variable nebula. A favourite of mine  for many years, well placed in the Winter sky in Monoceros. NGC2261 was the first object to be photographed with the famous 200" Mount Palomar telscope in 1948. 5 minute exposure in poor seeing conditions.		'The little dumbell', M76, so called for it's resemblance to M27. M76 can be found in Perseus. This image shows the loops of material extending out from the body of the nebula, not often seen on many published images. 6 minutes exposure.
	NGC 2392, the Eskimo nebula has a very bright central star of magnitude 8. Under high power in the telescope the impression of an Inuit face can be seen.		M78 in Orion, a 10 minute exposure taken in poor seeing conditions.
	The Eagle nebula, M16 in Serpens. Taken from COAA in 1997 via the 0.5m reflector and a 4 minute exposure. The Eagle nebula was made famous by the Hubble space telescope image showing immense detail in the 'pillars' which can be seen on a much smaller scale in this image.		NGC 6781 can be found in the summer sky in Aquila. Not very well known, this planetary nebula can be seen visually in most instruments even under light polluted conditions. This image shows some detail in the bubble of glowing gas and the surrounding rich Milky Way star field.

 

Planets & Satellites
	Saturn taken in October 1997 before the rings were as open as now (2003). This image was taken with eyepiece projection at f27 and a 0.2s exposure. Six images were averaged to achieve a better signal to noise ratio.
	Jupiter, 24th August 1998 at 2308 UT, f27 0.05s. The image shows (left to right) Io in transit, the shadow of Ganymede and the great red spot near the limb. Nine images were averaged and the composite unsharp masked.
	Mars imaged on April 29th 1999, 2148UT, CM=55°. Details as above with eyepiece projection at f27, 0.05s. Seven images were averaged. The dark region to the north (top) is Acidalia Planitia with Chryse (centre) and the Argyre region to the south. The image was taken under very poor conditions of haze and moonlight, with Mars just above a house roof!
	Taken on 6th September at 22:37UT CM=221 degrees Coolpix 885 used afocal to take a 40s AVI file. Processed best frames in Registax. 14" f5.2 reflector with 6mm X2 Barlow
	This is an image of Saturn's 16th magnitude satellite Phoebe, taken on January 21st 1999 at 19:08 UT. The image is a mosaic of several CCD frames to include Saturn (Saturn's image is overexposed but an internal reflection can  be seen). How do I know it was Phoebe? The frame with Phoebe in was calibrated using the GSC and a position derived which, remarkably, matched the JPL ephemeris exactly! The position (unrefracted, J=2000) was measured as 01h 46m 39.09s +08° 24' 21.6"

 

Animated GIFs
Barnard's Star This is an animated GIF is composed of four images of Barnard's star taken 5, 2 and 1 year apart. First in 1991 on 4th June, 5min exposure on hypered Tech Pan 2415 film, second in 1996 on 24th June, 30s exposure using an SXL8 camera (kindly loaned at the time by my friend Eric Strach) and the last two in 1998 and 1999 using the SX mono camera. Images were exported as JPG files, aligned and made into the animated GIF seen above! A crude pixel to pixel measuremet of the motion over 5 years gave just over 10" per annum, very close to the published value of 10.36" per annum.		Pluto 1998 This animated GIF of Pluto was made up of images taken from COAA in the Algarve region of Portugal. It is composed of 3 images taken on three consecutive evenings (it's always pretty clear over there!)  via a 6" f6 reflector and the Starlight Xpress mono CCD.