First CMOS image

I finally committed to getting a monochrome CMOS camera, ZWO ASI1600mm, with filter wheel and LRGB filters.

The learning curve was pretty steep and to date, my new work flow is something like:

1. Use unity gain (139). I used an offset of 2 1I think, but this should have been 50+.

2. My skies are Bortle 4, so using this table:

it means for F10, the luminance exposure should be 114s.

Having said that,  SGL advice seems to be :

 "For Gain 139 with 56 offset ,  background target ADU is 1386.  In order to find exposure times set  telescope  and at astro dark  take some test exposures at varying exposure times until you get one where the background level is 1386 and I do this for each filter and record times etc." (Pixel Aid in APT should allow the ADU to be measured)

3. Luminance filter : take flats, darks and dark flats

4. Red filter, take flats (exposure time? Not sure, but should be aiming to get a certain ADU reading)

5. Green filter, take flats (ditto)

6. Blue filter, take flats (ditto)

Take images of the target at L, R, G and B, using 1x1bin for L and 2x2 for R, G and B. Not sure what the exposure times should be for the R, G and B images,; using 114 s at the moment.

Processing:

Align and calibrate in DSS, using a reference frame 

Save as L, R , G and B

Use PS to:

 a) produce a RGB image and stretch it

b) produce a L image and stretch it

c) Combine them, using Luminosity as the blending mode

Use Lightroom to try and develop the colour more, set black ,etc.

This is my first image, based on around 4 hours of luminance  and 1 hour 20 mins of R, G and B. All exposure were at 114 (probably wrong for the colours). No calibration frames, hence the blotchiness.

NGC 4565 CMOS image

NGC 4565 The Needle Galaxy DSLR image

Compared with my DSLR image of the same galaxy, this has better resolution and less noise. Star colour is better but I think they are overexposed. Still, it is in colour and has only taken about 12 hours of fiddling to learn a technique that does actually give colour! There were a LOT of 'monochrome' moments on the way.

Black eye and Needle

A lovely clear night. I tried a few targets but settled on a pair of galaxies that I had seen someone else had imaged recently and looked quite interesting. I also had a look at two spectacular targets, the Needle Galaxy and the Black Eye galaxy/ Everything was taken at ISO 1600, with 240 or 300s subs.

M64 Black Eye Galaxy

Messier 65 The Black Eye Galaxy

Wikipedia: The Black Eye Galaxy (also called Evil Eye Galaxy and designated Messier 64, M64, or NGC 4826) is a relatively isolated spiral galaxy located 17 million light years away in the northern constellation of Coma Berenices. It was discovered by Edward Pigott in March 1779, and independently by Johann Elert Bode in April of the same year, as well as by Charles Messier in 1780. A dark band of absorbing dust in front of the galaxy's bright nucleus gave rise to its nicknames of the "Black Eye" or "Evil Eye" galaxy.

NGC 4565 The Needle Galaxy

The Needle Galaxy NGC 4565

Wikipedia: NGC 4565 (also known as the Needle Galaxy or Caldwell 38) is an edge-on spiral galaxy about 30 to 50 million light-years away in the constellation Coma Berenices.  It lies close to the North Galactic Pole and has a visual magnitude of approximately 10. It is known as the Needle Galaxy for its narrow profile. First recorded in 1785 by William Herschel, it is a prominent example of an edge-on spiral galaxy.

NGC 5908 and NGC 5905

NGC 5908 and NGC 5905

Located in the constellation of Draco, NGC 5905 and NGC 5908 are two spiral galaxies that are relatively near to each other. NGC 5905, in the upper-left corner, is seen face-on; whereas NGC 5908, in the lower middle is seen edge-on. NGC 5908 looks remarkably similar to M104, the Sombrero Galaxy. The many bright, stars in the image are stars within our own galaxy. At an estimated distance of 140 million light years away, NGC 5908 has a fairly small bulge. 

Some Messiers

Messier 87. This is the galaxy that has had its supermassive black hole imaged in radio wavelengths. recently, the first time one has ever been seen. It  has an enormous jet of material hurtling out of its core at close to light speed, thousand of light years long. I was surprised to  find that I can see the relativistic jet on my image, very exciting.

Messier 87

Relativistic jet emerging from the galaxy M87

Wikipedia:  Messier 87 (also known as Virgo A or NGC 4486, generally abbreviated to M87) is a supergiant elliptical galaxy in the constellation Virgo. One of the most massive galaxies in the local universe, it has a large population of globular clusters—about 12,000 compared with the 150–200 orbiting the Milky Way—and a jet of energetic plasma that originates at the core and extends at least 1,500 parsecs (4,900 light-years), traveling at a relativistic speed.

The core contains a supermassive black hole (SMBH), designated M87*,[31][66] whose mass is billions of times that of the Earth's Sun. This black hole is the first and, to date, the only one to be imaged.


MEssier 97 The Owl Nebula. On a MUCH smaller scale, though 'astronomical' byEarth standard, is the planetary nebula M97. This is what is left when a red giant 'blows off' its atmosphere and shrinks to a white dwarf. The fate of our sun in a few billion years.

M97 The Owl Nebula

Wikipedia:  The Owl Nebula (also known as Messier 97, M97 or NGC 3587) is a planetary nebula located approximately 2,030 light years away in the constellation Ursa Major. It was discovered by French astronomer Pierre Méchain on February 16, 1781. When William Parsons, 3rd Earl of Rosse, observed the nebula in 1848, his hand-drawn illustration resembled an owl's head. It has been known as the Owl Nebula ever since.

The nebula is approximately 8,000 years old. It is approximately circular in cross-section with a little visible internal structure. It was formed from the outflow of material from the stellar wind of the central star as it evolved along the asymptotic giant branch. The nebula is arranged in three concentric shells, with the outermost shell being about 20–30% larger than the inner shell. The owl-like appearance of the nebula is the result of an inner shell that is not circularly symmetric, but instead forms a barrel-like structure aligned at an angle of 45° to the line of sight.

Galaxy Season..oh and a globular cluster

I looked at all sorts , wasn't in the mood to take several hours of exposures of just one object, it nver seems to pay off in terms of quality with my aging DSLR. This is soon to be replaced with a CMOS camera, monochrome, that can be used with  luminance, red, green and blue filters to get coloured images. Will be a steep learning curve since its a very different device to a DSLR.
Anyway, all the exposures add up to no more than an hour for any one object, at ISO's of either 1600 or 3200 , hence the noise in some).


M3 Globular Cluster in Canes Venatici

M3 Globular Cluster in Canes Venatici

Wikipedia: Messier 3 (M3 or NGC 5272) is a globular cluster of stars in the northern constellation of Canes Venatici. It was discovered on May 3, 1764 and was the first Messier object to be discovered by Charles Messier himself. 

 M3 has an apparent magnitude of 6.2, making it a difficult naked eye target even with dark conditions. With a moderate-sized telescope, the cluster is fully defined. 

This cluster is one of the largest and brightest, and is made up of around 500,000 stars.It is estimated to be 11.4 billion years old . It is located at a distance of about 33,900 light-years away from Earth.

NGC in Serpens Caput, showing two quasars....just..honest!

NGC 3044 with two quasars (arrowed)

Messier 101 in Ursa Major, the Pinwheel Galaxy

M101 in Ursa Major

Wikipedia: M101 is a large galaxy, with a diameter of 170,000 light-years. By comparison, the Milky Way has a diameter of 258,000 light years. It has around a trillion stars, twice the number in the Milky Way. It has a disk mass on the order of 100 billion solar masses, along with a small central bulge of about 3 billion solar masses.

Messier  51 in Canes Venatici - The Whirlpool Galaxy

The Whirlpool Galaxy and friend NGC 5195

Wikipedia: The Whirlpool Galaxy, also known as Messier 51a, M51a, and NGC 5194, is an interacting grand-design spiral galaxy with a Seyfert 2 active galactic nucleus.
It lies in the constellation Canes Venatici, and was the first galaxy to be classified as a spiral galaxy. Its distance is estimated to be 23 million light-years away from Earth.
Whirlpool Galaxy lies 23 million light years from Earth and has an estimated diameter of 76,000 light years. Overall the galaxy is about 76% the size of the Milky Way. Its mass is estimated to be 160 billion solar masses.

A black hole, once thought to be surrounded by a ring of dust, but now believed to be partially occluded by dust instead, exists at the heart of the spiral. A pair of ionization cones extend from the active galactic nucleus.

Spiral structure
The pronounced spiral structure of the Whirlpool Galaxy is believed to be the result of the close interaction between it and its companion galaxy NGC 5195, which may have passed through the main disk of M51 about 500 to 600 million years ago. 

Leo Triplet

A quick glimpse before the clouds rolled in. 16 x 240 s, so a pretty mucky image!

Leo Triplet of Galaxies

I seem to be getting a lot of vignetting and a bright bar at the bottom of the image, plus a dust spot. Probably need new flats but I might also have to have a look at the optical train. Edit: Just checked on SGL and if the camera is rotated, new flats are needed!


Wikipedia:The Leo Triplet (also known as the M66 Group) is a small group of galaxies about 35 million light-years away in the constellation Leo. This galaxy group consists of the spiral galaxies M65, M66, and NGC 3628.

The group consists of the galaxies Messier 65, Messier 66 and NGC 3628, also known as the Hamburger Galaxy. The Leo Triplet lies at an approximate distance of 35 million light years from Earth.

Messier 66, the largest and brightest member of the Leo Triplet, is roughly 95 light years across. It has an apparent size of 9.1 by 4.2 minutes of arc and an apparent magnitude of 8.9.

Messier 65 has a visual magnitude of 10.25 and occupies an area of 8.709 by 2.454 arc minutes of apparent sky. It is an intermediate spiral galaxy, poor in dust and gas, and shows little evidence of star formation.


NGC 3628 is an unbarred spiral galaxy with a visual magnitude of 10.2. Seen edge-on, the galaxy occupies an area of 15 by 3.6 arc minutes and appears transected by a broad band of dust that stretches along its outer edge, hiding the young stars in the galaxy’s spiral arms.

The three galaxies in the M66 Group have all been affected by gravitational interactions with each other. This is evident in the deformed, drawn out spiral arms of M66 that are experiencing a high rate of star forming activity and in the warped, inflated disk of NGC 3628. With a prominent tidal tail consisting mainly of young blue stars, NGC 3628 seems to be the most affected of the three, while M65 appears to have suffered the least damage from the interaction. The tidal tail of NGC 3628 spans over 300,000 light years, but is very faint and does not always appear in images of the galaxy.

The universe is a big place....Abel 1367

Abell 1367.  This image is based on 19 x 300 s , plus flats and bias. It shows a LOT of galaxies, in a grouping called Abell 1367. In this image you are looking at part of one of the biggest structures in the Universe, the Great Wall.

Abell 1367

Wikipedia:
The Leo Cluster (Abell 1367) is a galaxy cluster about 330 million light-years distant (z = 0.022) in the constellation Leo, with at least 70 major galaxies. The galaxy known as NGC 3842 is the brightest member of this cluster. Along with the Coma Cluster, it is one of the two major clusters comprising the Coma Supercluster, which in turn is part of the CfA2 Great Wall, which is hundreds of millions light years long and is one of the largest known structures in the universe.

The overlay from Astrometry gives some of the galaxies visible in the image.

Overlay identifying some of the galaxies in the Abell 1367 group.

Some galaxies in Leo

The galaxy group Hickson 44 in Leo. This is based on 29 x 240 s, plus bias and flats.

Hickson 44 in Leo

There are some other galaxies near by, some of which are names in this overlay from Astrometry.net:

Overlay from Astrometry, naming the other objects

The main ones are NGC 3190, NGC 3185, NGC 3187 and NGC 3193. NGC 3190 has a well defined dust lane. NGC 3187 is a barred spiral galaxy with two arms. NGC 3193 is an elliptical galaxy.

The light captured by my camera last night left these galaxies just after the extinction event killed the dinosaurs on Earth.

From APOD: Galaxies, like stars, frequently form groups. A group of galaxies is a system containing more than two galaxies but less than the tens or hundreds typically found in a cluster of galaxies. A most notable example is the Local Group of Galaxies, which houses over 30 galaxies including our Milky Way, Andromeda, and the Magellanic Clouds. Pictured above is nearby compact group Hickson 44. This group is located about 60 million light-years away toward the constellation of Leo. Also known as the NGC 3190 Group, Hickson 44 contains several bright spiral galaxies and one bright elliptical galaxy on the upper right. The bright source on the upper left is a foreground star. Many galaxies in Hickson 44 and other compact groups are either slowly merging or gravitationally pulling each other apart.

Well, at least the moon was bright...

Same old story, almost as soon as it is properly dark, misty clouds appear and thicken. So, I gave up on DSO's and decided to try imaging the moon. Focus is an issue; as you adjust the focus manually, the whole telescope vibrates, so it is pretty hit and miss. I also tried using the telescope at F10 and with a 2 x magnifier (waste of time, makes it F20 , blurry and dim!)

Anyway, fruits of my labours, after ditching out of focus ones and the blurry dim ones:

Plato and the Alpine Valley

Rupes Recta and Rimae Pitatus , lower right of centre

Fra Mauro, Bonpland and Parry