Messier 33

 M 33 is the third largest galaxy in the Local Group, after the MilkyWay and M 31. The spiral structure is clearly visible in the images below. Initially discovered before 1654, the galaxy was rediscovered by Charles Messier in 1764. William Heschel also catalogued the galaxy in 1784, and it was among the first spiral nebulae identified by Lord Rosse. Edwin Hubble observed classical Cepheid stars in the galaxy, allowing him to demonstrate that M 33 was a galaxy in its own right.

For comparison, I've posted two images of M 33. The first consists of about 5 hours of data in 45 second segments, captured over two nights. The second is one night of data for comparison (2.5 hours in 45 second segments). Note the increase in the extent and detail of the galaxy in the longer exposure.

I have also included an astrometry annotated image, showing several of the galaxy's components visible in the pictures. Click and zoom for larger images. I have also added an image with clarity boosted to show details of the clouds of gas and dust near the core.

Tech card: RASA 8, DS10C, DMZ filter 

M 31 Reprocessed

 The big question in astrophotography is, "when  do I stop reprocessing?" Here are two more processed images of M31. The first is balanced to show the vivid colors in the galaxy itself, the second is processed to bring out more of the dust and gas clouds surrounding the galactic core. Click for larger versions

Messier 16

 As we head towards Winter, many of the summer imaging objects begin to disappear from the sky. The Eagle Nebula (M16) is not visible from my site here in Charlotte as it never rises above the surrounding trees and houses. This image was taken in Northern Indiana with my very basic portable setup--a WO GT-71 21st anniversary edition scope with FR/FF, a DS10C imager and L-eXtreme filter, and a venerable, first-generation iOptron SmartEQ Pro mount. The edge stars are distorted because I have not yet found the correct spacing distance for the FR/FF on the GT-71. The spacing on the 21st Anniversary Edition is different from the standard scope (even though WO tech support denies this--but it is impossible to achieve focus with the scope using their recommended spacer setup). 

This image represents about one hour of total integration time (30-second subs). It is a wide field view of the nebula and you can just see the Eagle at the center (see cropped image and/or click and zoom). I manually dithered the scope every 20 integrations. This final image is a crop of the original capture. 

Messier 31

November is the best month to observe our nearest large galactic neighbor, Messier 31. While M31 was observed and cataloged by Persian astronomers in 964, it was not recognized as an external galaxy until 1925, when Edwin Hubble observed a Cepheid variable star in the galaxy and was able to establish that the ‘nebula’ was definitively outside our own galaxy. Hubble’s work settled the ongoing ‘great debate’ about whether the observed spiral nebulae were part of our galaxy or were ‘island universes’ beyond it.

With its bright core, spiral arms and dark lanes of gas and dust, it is a wonderful object for astro imagers. This image was taken with a narrowband filter, which highlights red HII regions in the spiral arms. The large image shows the whole galaxy and the crops of the spiral arms and core show some of the wonderful detail in this object.

Tech card: RASA 8; DS10C; NBZ filter. The final image integration time was 2.9 hours of 40 second subs.

Click on the images to see larger versions, then click again to zoom even further.

The bright, greenish patch at the 7 o'clock position is NGC 206, a bright region of star formation in M31 itself.

Details of the red H II regions and swirling dark dust lanes are visible in this crop of the core regions of the galaxy.

Mars!

 After my Jupiter imaging session last night, I turned my attention to Mars. From my site, I can only currently image Mars when it is low in the sky. As it rises, it disappears into the trees that surround the observatory site. Last night's image was taken at about 2:00 UT. Mars was low in the NE sky. I imaged with the 125 mm Mak and 2x Barlow. I managed to get about 1800 frames before trees intervened. This image shows very little detail, but faint markings are visible and the gibbous phase is apparent. 

The 2022 opposition is not particularly favorable. The maximum disk size on December 8 is 17 arcseconds--as compared to 24.2 arcseconds in the favorable opposition of 2018.

Jupiter!

The current full moon (the Full Beaver Moon) limits deep sky imaging, so I dug out my old first-generation ETX 125 OTA (I still have the original drive base and Autostar and they still work) and mounted it on the iOptron SmartEQ Pro GEM and set out to image Jupiter last night. My camera of choice for this session is the Mallincam Skyraider-SLP. Although it is a USB 2.0 camera, it can capture at a pretty decent speed at 1024 x 768 resolution.

The first image is a stack of approximately 2,400 images (best 70% of a stack of 3,000+) captured at 45 fps at 1024x768 with a 2x Barlow (f/30). The images were stacked and processed in Registax 6 and tweaked in AstroSurface, Affinity Photo, and Microsoft Photo. I happened to start imaging just as Io started a transit across the disk (I only saw it after processing); Io is visible to the left just entering the disk. The Great Red Spot and several whorls and condensations in the cloud belts are also visible in the image. Given the 5-inch aperture and the fact that the wind was shaking the mount throughout the imaging session, the result is not too bad.

Despite the wind, imaging conditions and seeing were quite decent. I decided to pull out a piece of equipment I have never used—a 5x Barlow. Of course, imaging at f/75 has some challenges (!). The biggest issue was that the capture rate fell to 4.5 fps. I could have boosted gain, but I find that gain adds a great deal of noise to captured video images, and I never boost it above 40%. I was surprised to see a usable image, and I captured about 2,500 and stacked about 1700 for the second image. The biggest disadvantage is that the slow capture rate cannot counteract atmospheric blurring. The result is a smooth and “artistic” looking image, but without much detail (Io was still transiting, and it cannot be seen in this image). UPDATE: Thanks to the advice of a colleague on the Mallincam Group, I RGB balanced these images. I used Dyadic wavelets in reprocessing, and Io can now be seen in the second image, too, transiting toward the middle of the same belt as the GRS (the South Equatorial Belt [SEB]).

All in all, I was pretty happy with the session. I’m looking forward to Mars a little later in the month when it will be well placed for imaging from this site.