New Camera, New Images

In February, after several years of using uncooled, submegapixel cameras from Meade, I decided to upgrade to a cooled, multimegapixel camera. I chose the Orion Starshoot Pro, which offers a very large 6.1 megapixel CCD chip and TEC cooling.

As with any new piece of equipment there was the inevitable learning curve. The Starshoot Pro, not surprisingly, produces very large image files. Learning to properly stack and process images with the included Maxim DL Essentials software was also an adventure, though one well worth the effort. While considerably more effort is required to use the Maxim software to capture images, compared to Meade's simple Envisage, Maxim proved more useful in combining images taken over multiple nights.

Naturally, the new camera's arrival was followed by weeks of cloudy nights. In the two months that I have had the Starshoot Pro, there have only been about 10 reasonably clear nights. Nonetheless, that has been sufficient to produce a number of good images that clearly show the superior abilities of the Starshoot Pro.

Better still, with the DSI Pro no longer needed for imaging, I have been able to use it for guiding, attached to a 70mm refractor piggybacked on the 6" LXD-75. For the purpose of guiding, Meade's Envisage software works reasonably well, allowing me to take five minute sub-exposures (300 seconds). Longer sub-exposures appear to work better with the Starshoot Pro, and the size of the individual images mean that longer subs mean fewer images overall to stack.

The following are some of the better images captured over the last two months with the Starshoot Pro.

M42

Season permitting, this is perhaps inevitably the first target one wants to image with a new camera. This image is a stack of 20, 30-second sub-exposures. The Starshoot Pro's larger CCD chip also permits the inclusion of the entire nebula and associated star clusters in the camera's field of view. The DSI Pro would barely have captured the nebula itself with the same telescope.

Perseus Double Cluster

The famed Double Cluster in Perseus (NGC 869 & 884), provides another example of the benefits of a large CCD chip. With the Meade DSI, even with a .5 focal reducer bringing the 6" Newt's focal ratio down to f/2.5, I was unable to fit both clusters in the camera's field of view. This is not a problem with the Starshoot Pro, which easily capture both clusters at f/5.

This image comprises 10, 60-second sub-expsoures.

M101

The Pinwheel Galaxy in Ursa Major. This image comprises roughly two hours of 300-second subexposures taken over two nights (3/17/09 & 4/17/09).

M97 and M108

The Owl Nebula and irregular galaxy M108 appear in the same field of view thanks to the Starshoot Pro's large chip.

M92

A globular cluster in Hercules. This image was compose from six, 300-second sub-exposures.

M5

Another globular cluster. The image is a stack of seven, 300-second sub-exposures.

M13

The great Globular Cluster in Hercules. This image is a stack of 8, 300-second sub-exposures.

M51

The Whirlpool Galaxy in Canes Venatici. This images was composed from two and a half hours of 300 second sub-exposures taken on 3/12, 4/05, and 4/16.

M63

The Sunflower Galaxy. As usual, a considerable amount of exposure time is needed to bring out the faint details in the galaxy's spiral disk. This image is composed of a total of six hours of exposure time from 300-second sub-exposures taken on 3/17, 3/23, 3/24, 3/25, 3/30 and 4/16.

M81 & M82

Once again, the Starshoot Pro's large CCD chip permits both galaxies to fit easily within the same field of view. This image comprises about two hours of 300-second exposures taken on 3/5 and 3/20.

October 2, 2008

10pm – 1am

NGC 7635

Cassiopeia's famed “Bubble Nebula” is an emission nebula appearing not far from the open cluster M52. The conspicuous bubble feature results from “stellar wind,” a stream of charged gas, emanating from a nearby massive star. The gas from the star repels the nebula's own gas and dust creating the spherical structure, which uncannily resembles a soap bubble riding on the wispy froth of the rest of the gas cloud.

This image comprises 60, 30-second sub-exposures.

M74 

This is a spiral galaxy, seen face-on, about 35 million light years away in the constellation Picses.

This image comprises 80, 30-second sub-exposures.

M33

Another attempt at the Triangulum Galaxy (see September 23 post). 

This image comprised 80 21.2-second images.

M1

Better known to most amateur astronomers as the “Crab Nebula,” M1 is  remains of a star that went supernova (exploded) in 1054 AD. The supernova was observed on Earth by Chinese astronomers/astrologers who had no idea what they were actually seeing. The expanding cloud of gas, dust and other debris – now about ten light years across - was given its name by Lord Rosse, who sketched it in detail in 1844, noting an intricate filamentary structure.

In 1968, astronomers identified a pulsating radio source emanating from M1. This turned out to be one of  the first examples of a pulsar, a rapidly rotating neutron star. Neutron stars are composed of “degenerate matter” so densely packed that a spoonful would weigh 10,000 pounds. They result from the rapid collapse of matter under extreme gravitational forces during a supernova. A neutron star may only tens miles in diameter, but spins rapidly – 30 times per second, in the case of the Crab Nebula pulsar. 

This image comprises 30, 21.2 second images.

September 23, 2008

NGC 1491

This small emission nebula lies in the constellation Perseus and is illuminated by an 11^th magnitude star near is center. I imaged NGC 1491 using the .5 focal reducer, but the nebula's small size clearly demands another image taken at prime focus to provide more detail.

This image comprises 50, 15-second images.

M33

This is a large spiral galaxy located in the small – and usually unnoticed – constellation of Triangulum, which lies south of the better known constellations of Andromeda and Aries. M33 is often referred to as the Triangulum Galaxy.

After the Milky Way and Andromeda galaxies, M33 is the third largest member of the Local Group of galaxies, lying somewhat farther away than M31. Under very dark skies, it is possible to glimpse the large, but very faint light from this galaxy, making it perhaps the farthest object visible to the naked eye. But very, very dark skies and an exact knowledge of where to look is required to see it without optical aid. Even with a telescope or powerful binoculars, M33 is difficult to detect in light-polluted suburban skies.

This image comprises 80, 15-second images.

NGC 896

This a rather large emission nebula in the constellation Cassiopeia. The nebula is too large to be complete captured by the DSI Pro, even using the .5 focal reducer. Nevertheless, the camera did capture some of the brighter areas of the nebula, and some of the dark clouds of dust that run through it. The more diffuse parts of the nebula will likely require significantly longer exposure times. NGC 896 is actually a small part of a much larger complex of nebulae and open star clusters, whose other parts include IC 1805 and IC 1848.

This image is comprised of 60, 15-second sub-exposures.

NGC 891

This is a spiral galaxy seen edge-on. NGC 896 was first noticed by William Herschel in 1783; Herschel, of course, considered it simply another nebula. The galaxy, which can be easily detected in small telescopes as a faint cigar shaped smudge, lies about 27 million light years away in the constellation of Andromeda.

This image comprises approximately 80, 15-second sub-exposures.

M52

This wonderful open cluster is easily observed with binoculars as a faint cloud of light amid Cassiopeia's dense star fields. A small telescope will easily resolve the cluster into a glittering field of hundreds of stars. 

Charles Messier first noted the cluster in 1774 as he searched for comets in the skies over Paris. Modern estimates place the cluster about 5,000 light years away. It appears to span roughly 19 light years in diameter.  

The following image comprises 30, 15-second sub-exposures taken with the .5 focal reducer. Some vignetting is apparent.

NGC 205/M110 

This dwarf elliptical galaxy is a satellite of the much larger Andromeda Galaxy (M31). In small telescopes it can be seen as a small, fuzzy point next to the ghostly oval glow of M31 itself. Charles Messier noted the object in 1773 in his drawings of M31, but never officially added it to his catalog. Herschel recorded it ten years later. It was posthumously added to Messier's great catalog in 1966.

Elliptical galaxies assume a generally spherical shape. They display a marked lack of dust and gas. This means that elliptical galaxies exhibit  very little star formation; this, coupled with the radial rather than rotational motion of stars within these galaxies lends them a relatively featureless appearance. Large numbers of globular star clusters are often associated with older elliptical galaxies. 

NGC 869 & 884

If you poured diamonds of varying sizes into two piles close together on a dark velvet surface, you would be recreating, in miniature, the glorious appearance of the justly famed Perseus Double Cluster.

The double cluster is visible to the naked eye as a faint patch on the Cassiopeia-Perseus border and is easily seen on dark, chill autumn evenings. Binoculars can resolve the clusters into hundreds of glittering stars. The double cluster is best view with good binoculars or small scopes at low magnification (or using wide-field eyepieces) whose fields of view can easily encompass both clusters at once for the optimal visual effect.

Even with the .5 focal reducer, the DSI Pro cannot completely fit both clusters in its FOV. The following image, however, manages to capture the center of both clusters. It comprises 30, 15-second images.

August 9, 2008

10:30-11:30pm

The night seemed perfect, clear and cool. But as soon as the scope was set up and aligned, th clouds began to arrive.

M29

Still my favorite cluster in the night sky, lying among Cygnus's ultra-rich star fields just a few degrees from gamma Cygni (Sadr). The cluster was discovered by Charles Messier in 1764, one of his first discoveries made while comet-hunting in the skies over Paris.

This image comprises 30, 15-second sub-exposures.

M29 is often dismissed as an unimpressive object.  Personally, I find the disparagement of this fine little cluster perplexing. True, it is not as magnificent as many – not having as many stars as M52, or gleaming as brightly as the Pleiades – but is has a charm all its own. And, in many cases, my own included may be the first object an amateur stargazer spots with a telescope in the summer sky.

Despite its location near a bright star (Sadr), it's not easily located by a novice observer, which makes its final discovery all the more rewarding, especially since it stands out clearly in the otherwise crowded region.

NGC 6946

Appearing on the border of the constellations of Cepheus and Cassiopeia, this magnificent spiral galaxy was first observed by William Herschel in 1798. Herschel, of course, had no idea what he was actually seeing, noting it as another nebula. Modern astronomers have recorded nine supernova (exploding stars) in NGC 6946 since 1917 leading to NGC 6946's popular description as the “Fireworks Galaxy.” It is thought to lie about 10 million light years distant from the Milky Way galaxy.

Due to the oncoming clouds, this was a hurried image, somewhat ruined as wispy clouds obscured the object even as the last sub-exposures were taken. The above image is a stack of 44, 30-second sub-exposures.

August 8, 2008

10pm –  3am 

Finally, a night with both a clear sky and cool temperature. Unfortunately, a mote of dust had settled, unnoticed on my focal reducer's lens. It's effect – a large black spot - did not become apparent until I started to process the images the next day. The spot lies in the lower left quadrant of, I'm sad to sav, every image.

NGC 7023

Known to many astronomers as the “Iris Nebula” due to its vaguely flower-like shape, this reflection nebula located in the constellation Cepheus, is actually surrounded by a dark nebula, which obscures the background starfield. The nebula itself reflects the light of a nearby 7^th magnitude star.

This image is comprised of 50, 30-second subexposures.

NGC 7380/Sh2-142

NGC 7380 is an open star cluster with an associated nebula complex in the constellation Cepheus. It is thought to be about 7,500 light years away.

This image is a stack of about 50, 30-second sub-exposures.

NGC 7538

Located in the constellation of Cepheus, NGC 7538, an unremarkable nebula, lays claim to having the largest known proto-star (a star in the process of forming) gestating inside it. The proto-star is believed to be 300 times larger than our solar system. The nebula is located 9,100 light years distant in an area of particularly active star formation.

This image is comprised of 50, 30-second sub-exposures.

NGC 281

Dubbed the Pac Man nebula by some observers, NGC 281 features a small open cluster (IC 1590) embedded near its center. The nebula itself is a stellar nursery, with dark dust lanes obscuring areas where new stars are slowly forming. The nebula lies about 10,000 light years away in the constellation  Cassiopeia.

The following image is a stack of 50, 30 second sub-exposures.

July 31, 2008

July 31, 2008

10pm –  12am

So few nights available for imaging in the high summer months. Must take any opportunity –even if conditions are less than optimal.

IC 5146

Often referred to as the “Cocoon Nebula,” IC 5146 is an emission nebula surrounding an open star cluster in the constellation Cygnus.  It is located about 4,000 light years away. It is thought to be a stellar nursery with stars forming inside it.

This image is comprised of 50, 30-second sub-exposures.

June 24, 2008

The month of June passed with mostly cloudy or hazy nights, providing few opportunities for imaging. When the clouds and haze weren't obstructing the sky, the bright moon was there to drown out the fainter DSOs. 

Nevertheless, the night of the 24th offered a relatively clear sky and cool air (which makes for steady viewing). So I pulled out the scope, and the DSI-C, and decided to take color images of some of the objects I imaged in the previous session with the monochrome DSI Pro. The Pro has a more sensitive chip and yields higher resolution, but the C can paint what it captures in glorious color, without the effort and hassle of shooting through individual color filters and later combining the images.  As I noted, I am lazy.

M16 

M17

M20

M27

NGC 6992