NGC 2244 - The Rosette Nebula

The Rosette Nebula -- a stunning emission nebula associated with the star cluster NGC 2244 -- is a complex and challenging target, worthy of repeated efforts.

Appearing in the constellation Monoceros (the Unicorn, east of Orion), the nebula and cluster are estimated to be about 5,000 light years distant, spanning a diameter of about 130 light years.

For astro-imagers, capturing the detail of the swirling gas clouds and the numerous bok globules (dark nebulae composed of dust and gas found in many emission nebulae), while preserving the Rosette's glorious colors, usually requires combining multiple images shot through a variety of filters.

The Rosette covers a wide area of sky. Each of the below images was taken with the ASI1600 through the 72mm refractor.

The above image was my first try this season, taken in September. It comprises 12, 360-second exposures through the Ha filter and 10, 180-second exposures through the R, G and B filters.

This month, I returned to the Rosette, capturing just over two and a half hours (31, 300-second sub-exposures) through the Ha filter, producing the above image. Ha brings out an incredible amount of detail of the nebula's structure.

I then captured an hour and 15 minutes of 300-second sub-exposures through the OIII filter, combining them with the previous Ha data to create the above HOO palette image. This narrowband-only exposure keeps the general color of the nebula, while revealing a lot of subtle detail. Total exposure time is 3 hours and 45 minutes.

Last weekend, I captured 2.5 hours of RGB data (10, 300-second sub-exposures per channel), which I then combined with the existing 2.5 hours of Ha data, creating the above image. Total exposure time for this image is about five hours.

Time and weather permitting, the next step will be to obtain more OIII data and possible SII data, creating a better HOO palette image and a separate SHO palette image -- and then combining the SHO an RGB data for a final image for the season.

November Highlights

The weather has not been especially kind to stargazing so far this month, but I have managed to spend a few clear nights imaging.

NGC 2264 - The Cone Nebula and Christmas Tree Cluster

The constellation Monoceros - the Unicorn - to the east of Orion has a number of interesting objects within its borders. The Rosette Nebula (NGC 2244) is one, the below complex is another.

NGC 2264 refers to both the Cone Nebula (the dark conical projection toward the lower middle of the image) and the Christmas Tree cluster (which looks like the outline, in blue-white stars, of an upside down Christmas tree, in the middle-to lover part of the image). Also apparent in the image is the Fur Nebula, which appear as undulating waves of red toward the upper middle of the image.

This image, taken with the ASI1600 is composed of 17, 360-second images taken through the Ha filter and 10, 300-second images, taken through the R, G and B filters, using the 72mm telescope. Total exposure time is four hours and 12 minutes.  The image has been cropped to concentrate on the objects at the center. I will take the time to image these objects with the higher-magnification 127mm next month.

M42 - The Great Orion Nebula

This massive stellar nursery is so bright that is one of the few nebula visible to the naked eye. When you look at Orion, the nebula appears as the fuzzy area south of the three-star belt. sometimes called the sword of Orion.

The above image is RGB only -- true color. The image comprises 10, 180-second images taken through the R, G and B filters, using the 72mm refractor. Total exposure time is two and one half hours. The ASI1600 did a nice job capturing detail in both the Orion Nebula and the Running Man Nebula (Sh2-279) which appears to the right of Orion Nebula and appears mostly in blue.

This is the same RGB image as above, but with 50 minutes of Ha (10 x 180 seconds) added in. The Ha data enhances the nebula and shows the sweeping waves of hydrogen gas that surround the entire nebula complex.

IC 1805 - The Heart Nebula

Appearing in Perseus, the Heart Nebula is an extended emission nebula with an unmistakable shape. It was first recorded by William Herschel in 1787 and is located about 7,500 light years from Earth.

The above image comprises two hours of Ha data (20x300s) and 2.5 hours of RGB (10x300s, per channel), for a total exposure time of 4.5 hours. It was taken with the ASI1600 through the 72mm refractor.

IC 434 - The Horsehead Nebula

It is always impossible to resist this object. I had produced an excellent image last month, but decided to go back this month to get better color data.

The above image combines two hours of Ha data (20x360 seconds) taken in September, with three hours of RGB color data (12x300 seconds, per channel), taken this month. Total exposure time is five hours.

The Fall Sky

Cooler autumn nights usually make for better imaging -- assuming the sky is clear, of course. This offers an excellent opportunity to capture the gems of the Fall and Winter (after midnight) skies.

M1 - The Crab Nebula

This supernova remnant shines relatively brightly in Taurus. It can be seen as a small smudge of light in even modest telescopes. Long-exposure imaging brings out the filamentary structure. But it looks nothing like a crab.

This image is composed of  20, 180-second images taken through the Ha filter and 10, 180-second exposures taken through the R, G and B filters, using the ASI1600 and the 72ED.  I'm a little surprised the image came out so well using the 72mm scope. In coming weeks, I will re-image this target with the 127mm scope, which seems like a much better match to M1's apparent size.

M45 - The Pleiades

No fall can go by without taking the opportunity to image the Seven Sisters. This cluster in Taurus immediately draws the eye as soon as it rises and is an irresistible target for binoculars or small scopes.

The above image comprises 12, 300-second sub-exposures shot through the R, G and B filters for a total exposure time of three hours.

NGC 891 - Silver Sliver Galaxy

This is a spiral galaxy, probably much like our own Milky Way, seen edge-on. It appears in the constellation Andromeda and is estimated to be about 27 million light years distant.

This image is composed of 11, 180-second sub-exposures taken with R, G and B filters through the ASI1600 and the 127mm refractor.

M31 - The Andromeda Galaxy

Like the Pleiades, M31 is almost an obligatory image to take every year. That does nothing to diminish the majesty of the magnificent spiral galaxy just 2.3 million light years away. M31 is now thought to be a truly massive galaxy, roughly twice the size of our Milky Way with a diameter of more than 200,000 light years (compared to 100,000 for the Milky Way) and home to a trillion stars.

This image is composed of 45 minutes of exposures shot through the L, R, G and B filters using the ASI1600 and 72ED. Total exposure time is three hours.

IC405 - The Flaming Star Nebula

This colorful emission and reflection nebula complex, which surrounds a blue-colored star in Auriga, always makes for a dramatic image.

Taken through the 127mm scope, this image combines 10, 180-second sub-exposures taken through the Ha, R, G and B filters. The total exposure time is two hours.

IC 405 and IC 410

IC 405 (above) appears in the sky close to IC 410, though the two are not really close together. IC 405 is estimated to be about 1,500 light years distant, while IC 410 is much farther away at about 12,000 light years. Nevertheless, the two nebula look fantastic when imaged in the same field of view.

This is a two panel mosaic taken through the 72mm scope with the ASI1600. Each panel is an HaRGB image with a total exposure time of about two hours.

A Preview of the Winter Sky

Summer is over and we turn now to the Fall and Winter skies, which are rising to fill the night. The last few weeks have been spent getting some early images of the jewels that fill Orion, Perseus and Monoceros.

Here's a sneak peak at the coming attractions:

IC 434 - The Horsehead Nebula

This is a unique and crowded area of space. Part of the Orion Molecular Cloud complex, the Horsehead, seen at the center of the below image, is a column of sooty dust rising into the background of a bright emission nebula. The Horsehead is estimated to be two light years wide and four light years tall. It is between 1,400 and 1,500 light years distant.

This image includes the Flame Nebula (NGC 2024), seen at the lower left of the image. This bright emission nebula is illuminated by several hundreds young stars inside it.

This image is composed of 20, 360-second exposures in Ha and 5, 180-second exposures in R, G and B, taken with the ASI1600 through the 72mm refractor.

NGC1499 - The California Nebula

This large, but relatively dim, emission nebula appears in the constellation Perseus. It is estimated to be about 1,000 light years distant. It derives its name from the apparent similarity of its overall shape to that of the U.S. state of California. 

This image is composed of 10, 360-second exposures in Ha and 10, 180-second exposures in R, G, and B, taken with the ASI 1600 and the Sky-Watcher 72mm ED refractor.

Rosette Nebula

This beautiful emission nebular appears in the constellation Monoceros. The nebula is quite large, requiring a wide field telescope to capture it's entirety. Estimated to be about 130 light years across, the nebula is about 5,000 light years distant.

At the center of the Rosette appears the star cluster NGC 2244. The Rosette is a stellar nursery with thousands of new stars forming deep inside.

This image was composed of 10, 360-second exposures in Ha and 8, 180-second exposures in R, G, and B, taken with the ASI 1600 and the Sky-Watcher 72mm ED refractor.

As the season progresses, and these objects rise at more convenient (and less dew-prone) times, it is my goal to obtain at least 10 hours of exposure time on each to bring out their details.

The Veil Nebula

Summer is ebbing. The great seasonal triangle of Vega, Deneb and Altair opens the night higher and higher in the sky and soon will at zenith by 10pm. That means that I soon won't be able to image targets in Cygnus, since they are slowly slipping behind the house and out of my -- way too limited -- field of view.

So, before that happens, I figured it was time to capture the glories of The Veil Nebula. This sweeping collection of filamentary wisps of nebulosity is all that remains of a massive star that went supernova between 7,000 and 10,000 years ago. The Veil covers a considerable amount of sky and its constituent components include NGC 6992, NGC 6995 and NGC 6960.

The Veil is particularly strong in hydrogen and oxygen, which makes it an excellent target for narrowband imaging. The following images were taken using the Ha and OIII filters, combined to create bicolor images with a HOO profile.

Spread out over so large an area, the Veil is impossible to fit into one image, even with the Evostar 72ED's quite wide FOV. Thus, I imaged the nebula in two parts: the Eastern Veil, including NGC 6992 and then the Western Veil, including NGC 6960. Late August weather hasn't been kind to sky watchers here in New York, but I managed to get four nights over the past two weeks, spending two nights on each image.

The two resulting images were then combined in Pixinsight to create a single image that captures most, though not all, of the Veil Nebula complex.

The Western Veil, including NGC 6960:

Captured on two nights in mid August. The below image is composed of 88, 180-second sub-exposures - 44 shot through the Ha filter and 44 through the OIII filter. The image nicely captures Pickering's Triangle, the expanse of twisting, gossamer filaments to the right edge of the image.

The Eastern Veil, including NGC 6992

This portion of the Veil is a favorite target for imagers. I have shot it before with both the DSLR and the SSP -- and I think I managed to capture parts of it years ago with the Meade DSI. But the ASI1600 does it particular justice. This image was captured over two nights and is composed of 78, 180-second sub-exposures, including 42 shot through the Ha filter and 36 through the OIII filter.

The Veil Nebula Complete (well, mostly)

With both the Western and Eastern sections captured, I used dnaLinearFit, Star Alignment and GradientMergeMosaic in Pixinsight to combine the two images and produce the below mosaic, which captures the majority of the nebula complex. Some nebulosity was clipped at the top and bottom of the image, which leaves me something to target next year.

I am very pleased with both panels and the final combined mosaic. It is a nice way to see summer come to its end.

Summer 2019 - Major Upgrades

New Mount, New Camera, New Images

In December 2018, my old Meade LXD75 mount suffered a total R.A. motor failure. After a decade of far better service than I should have expected -- the LXD line was not Meade's best or most accurate equatorial mount -- it was time to move on. After considerable research, I settled on the Sky Watcher EQ6-R Pro, which I ordered through Highpoint Scientific.

The new mount quickly proved far more capable and reliable than the LXD, which was not unexpected. Since I had upgraded the mount, I decided it was time to do likewise with the camera. I had been using a Gary Honis-full spectrum modified Canon EOS T2i since 2014 and had reached its limits. After more research, I settled on a ZWO ASI1600MM Pro. This was a major change from the one-shot-color (OSC) imaging that I had been doing for years. But a switch to Mono (a monochrome chip), seemed like the next step in my imaging development. So I took the plunge. Since I still wanted to capture color images, and because I was interested in using Narrowband filters, I selected the ASI1600MM Pro kit with an electronic filter wheel and 31mm L, R, G, B, Ha, OIII and SII filters.

Naturally, once the new camera arrived in early April, six weeks of clouds and rain followed. During that time, I decide that, having spent money on a new mount and camera, I might as well purchase a new scope to go with them. I had grown a little tired of constantly collimating my 6" Orion Newtonian Astrograph, so I purchased a Sky Watcher Evostar 72 ED, a 72mm doublet refractor, which promised a very wide field of view. With the added .8 field flattener/reducer that already wide field was widened even more.

Having indulged myself with a new mount, camera and telescope, I decided to spend even more money. I purchased Pixinsight, the leading astro-imaging processing software and took a subscription to Photoshop. At this point, why not?

Between the software and camera, there was an inevitable learning curve, but by June, I was amazing myself with images that far better matched what I had long hoped to achieve in astro-imaging. The ASI1600 has proven extremely versatile and sensitive, allowing me to capture objects that were just too faint for the DSLR (and SSP before it). I had long avoiding Mono imaging because I figured it would be too difficult. However, the reality is that with contemporary electronic filter wheels and software (I use Astrophotography Tool - APT), the process is relatively simple. There are a few more steps, but not many, and the results amply justify the extra effort.

So, here are some of the highlights of the last eight weeks, through mid August.

NGC 884 & 869 - The Double Cluster

A preview of fall's coming attractions. Less than 20 minutes of exposure through RGB.

M8, M20 and NGC 6559

I am particularly pleased with this image, which captures M20, the  Trifid Nebula (upper middle/right), M8, the Lagoon Nebula (lower right) and NGC 6559 (lower left), in one image. More so, because this is actually two images that Pixinsight combined into a mosaic. The 72ED's FOV is generous enough the capture M8 and M20 in one shot, but not all three objects.

M11 - The Wild Dust Cluster

Under 20 minutes of RGB exposure time, but enough to bring out the dense starfield and wispy dark nebula in the region around the cluster.

M27 - The Dumbbell Nebula

This image is one of my first Narrowband images, a combination of Ha and OIII subs.

M31 - The Andromeda Galaxy

Another preview of fall. This image is composed of just over 30 minutes of 60-second RGB subs, which shows the considerable power of the ASI1600.

NGC7635, M52 & Friends

This image truly brought home the power of mono imaging and the sensitivity of the ASI1600. I have been imaging the beautiful cluster M52 (top/center) and NGC 7635, the Bubble Nebula (mid center/left), and NGC 7538 (lower center/right) for years, completely unaware of the other objects - Sh2-157 (the Lobster Claw - lower left) and extended nebulosity between NGC 7635 and NGC 7538 (mid to lower right). The DSLR was simply not sensitive enough to capture them.

NGC 7000 and NGC 5070 

This mosaic of two images capturing the North American Nebula (NGC 7000) and the Pelican Nebula (NGC 5070) puts just about every astro-image I'd taken before to shame. This image is under an hour of HaRBG integration, with subs of just 60 seconds.

NGC7023 - Iris Nebula

Notoriously difficult to bring out the dust clouds surrounding the Iris, but at just 5 hours of RGB integration, the ASI1600 does a good job.

NGC7293 - The Double Helix Nebula

Just under eight hours of Ha and OIII, with subs ranging from 600 seconds to 180 seconds.

NGC7822

A region of emission nebula and star clusters in Cepheus.

Sh2-101 - The Tulip Nebula

About an hour RGB integration in Cygnus.

Sh2-157 - The Lobster Claw

Spotted whilst imaging the Bubble Nebula (NGC 7635 - upper center/right), the Lobster Claw demanded its own image. About two hours of integration in RGB using 300-second subs.

September 2017

Summer's humidity and haze still lingers despite the calendar, but there have been a solid number of good nights this month. The following images were taken with the new Orion 6" f/4 Astrograph (with a GSO Coma Corrector) and the modified T2i camera.

NGC 6992

The most prominent segment of the eastern side of the Veil Nebula, this supernova remnant, stretches for 90 light years or more and is about 1,500 to 1,900 light years distant.

This image comprises 61, 60-second sub-exposures for just over an hour of total exposure.

NGC6960

The western segment of the Veil, and possibly it's most beautiful and ephemeral slice as a major filament appears to pass near a relatively bright star.

This image comprises 66, 60-second sub-exposures for a total exposure time of one hour and six minutes.

M31 - The Andromeda Galaxy

One of the most famous objects in the night sky and visible to the naked eye. Located about 2.5 million light years away and possibly twice the size of our own Milky Way galaxy, containing as many as a trillion stars.

This image comprises 79, 60-second sub-exposures for almost an hour and twenty minutes of total exposure time.

M33 - The Triangulum

Relatively bright, but notoriously difficult to image, this galaxy appears in Triangulum, near Aries and Pegasus and visually not far from M31. The galaxy is actually 2.3 million to 3.1 million light years away and is part of the Local Group along with the Milky Way and M31, but is the smaller of the three at just 60,000 light years across and containing perhaps 40 billion stars.

This image is composed of 25, 300-second sub-exposures for a total exposure time of two hours and five minutes.

NGC7830

Sometimes referred to as the Wizard Nebula, this emission nebula surround a small cluster of stars was first identified by Caroline Herschel in 1787. It is about 7,000 light years distant and appears in the constellation Cepheus.

This image comprises 22, 300-second sub-exposures for a total exposure time of two hours and fifty minutes.