TSS Monthly DSO Challenge for November 2023

[kt4hx]

A new month is upon us, and at least temporarily I am returning to the monthly version of the challenge vice the bi-monthly. For us northerners the weather is cooling noticeably as autumn has its grasp on us as we slowly work our way toward winter. Our southern friends are deeply entrenched in spring and looking forward to summer-time down under.

This edition has us visiting Cassiopeia once again along with a stoppage in Perseus and finally Aries for our northern targets. The southern portion of the challenge takes us to Sculptor and Phoenix. I do hope you enjoy adding these objects to your observing plans, and that you find something new that you have never visited before. But visiting an old friend can also be a relaxing thing to do from time to time. So let’s get out there and do some observing. I wish you good luck with your observing in November and hope that you will report your results for these objects here, whether you are solely a visual observer, or perhaps a sketcher, or a devout imager. We like it all here and always enjoy reading of your night sky exploits.


[Northern Celestial Hemisphere]

Collinder 463 (Cassiopeia, open cluster, mag=5.7, size=57.0’, class= III2p):
This cluster is part of the Collinder catalogue published in 1931 by Swedish astronomer Per Collinder, which contains 452 open clusters, 11 globular clusters, six asterisms, one stellar moving group, and one stellar association. It is located just over 8° north of mag 3.8 Epsilon Cassiopeiae (Segin), sitting inside of a rhombus of four stars of 4th and 5th magnitude (40, 42, 48 and 50 Cas).

Cr 463 is a large and spread out collection of 8th to 12th mag stars that is not significantly detached from the overall stellar field, but still is an interesting collection of stars. Depending upon the source I have seen its size listed as large as 57.0’ in diameter. Based on sky quality and aperture, one may see as many as 40 to 50 stars dotting the large apparent field of this cluster. Though not especially rich for the size of its field, I still found it curiously attractive.

As an aside here, John Herschel thought that the star 50 Cas was nebulous in nature and it found its way into the catalogue as NGC 771. He commented in his notes that "I suspect this star [50 Cas] to be nebulous." However, this is simply not the case and unfortunately there are several instances where he noted a false nebulous appearance to stars that simply was not there. However, this is the brightest example of a single star being listed in the NGC.

Messier 76 / NGC 650 & 651 (Perseus, planetary nebula, mag=10.1, size=2.7’x1.8’, SBr=11.5):
The famous “Little Dumbbell Nebula” was discovered in 1780 by Messier’s colleague and close friend Pierre Méchain. However, it was observations by William Herschel in 1787 that led to this object having two designations in the NGC. He described it as "two close together, their nebulosities run into each other; distance of their centers is 1 1/2 or 2'.” Because of its structure, it can sometimes appear as two distinct nebulous objects, hence the dual designators.

Located in the far western portion of Perseus, almost 1° NNW of mag 4.1 Phi Persei, it is fairly large for a planetary nebula. It is bipolar PN, with two brighter knots separated by a dimmer center where the very dim mag 15.9 central star resides. It can appear rather boxy in shape, with its northeastern portion (NGC 651) being brighter than the slightly curved southwestern knot (NGC 650). This is a most curious object and utilizing an O-III or narrow-band nebula filter will certainly boost its contrast in the eyepiece.

NGC 772 (Aries, spiral galaxy, mag=10.3, size=7.2'x4.3', SBr=13.8):
This is the brightest galaxy within the small zodiacal constellation of Aries, which is Latin for “ram”, and has represented this creature since Babylonian times. Our target object is also found in the Arp Catalogue of Peculiar Galaxies as Arp 78, representing the class of a spiral with a small high surface brightness companion. This small companion is the elliptical NGC 770 (mag=12.8, size=1.1’x0.8’, SBr=12.4). In deep images one can discern tidal streams linking the two galaxies as a result of their interaction. While NGC 772 was discovered by William Herschel in 1785, its much smaller companion wasn’t first seen until 1855 by R.J. Mitchell.

NGC 772 is located nearly 1.5° ESE of the double star Gamma Arietis (Mesarthim), whose components are evenly bright at magnitude 4.6 and 4.7 (sep~7.0”), with a combined brightness of 3.86. The fairly large oval disk of NGC 772 is tilted in a northwest-southeast orientation. Its overall appearance is typically of a faint diaphanous outer halo with a brighter core set within. Increasing aperture and particularly darker skies will of course enhance one’s view of this nice spiral. With careful study one may discern a subtle brightness northwest of the core and extending westward (an extended arm). The companion elliptical, NGC 770, lies just 3.5’ SSW of the core of the primary galaxy, and is more challenging to pick up as a faint and much smaller round dust bunny.


[Southern Celestial Hemisphere]

NGC 253 (Sculptor, barred spiral galaxy, mag=7.2, size=29.0’x6.8’, SBr=12.7):
This infamous galaxy is known by various nicknames, such as the Silver Dollar or Silver Coin Galaxy, Sculptor Galaxy, or Caroline’s Galaxy. This is the only galaxy that Caroline Herschel discovered, doing so in 1783 with her 4.2 inch sweeper telescope that her brother William built for her. During one of his observations of this object he wrote, "On looking at the nebula a long while the suspicion of its consisting of stars grows stronger as it begins to put on a faintly mottled appearance."

Situated just south of the Cetus-Sculptor border, it is located just over 7° south of bright 2.0 magnitude Beta Ceti (Diphda). This large object is one of the most prominent galaxies in the sky for the amateur observer to behold. Significantly inclined to our line of sight, it presents a large elongated oval glow. It can often seem to be of uneven illumination because of extensive dark lanes, which give it the mottled appearance described by William Herschel. From darker locations it can be glimpsed in binoculars and even optical finder scopes. Though more of a southern object even observers at mid-northern latitudes, with a decently low southern horizon, can get excellent views of this beauty. After all, it was discovered from the U.K.! This is magnificently bright for a galaxy and one well worth tracking down in the sky.

NGC 288 Sculptor, globular cluster, mag=8.1, size=13.0’, class=10):
The only globular cluster in the constellation of Sculptor is easily located just over 1.5° southeast of NGC 253. Caroline Herschel missed this object when she discovered NGC 253, but her brother William discovered it two years later in 1785, describing it as "pretty bright, large, oval round, brighter in the middle.”

Fairly bright and large, it can appear grainy to the eye in smaller apertures, hinting at possible resolution of some of its members. And in moderate apertures (8 to 12 inch) one may be able to resolve several stars across the face of its apparent disk. As a class 10 cluster, its core is not significantly compressed and only shows some weak concentration. This cluster being so close to bright NGC 253 provides one a nice opportunity to study to radically different objects, in close proximity. This cluster is a beauty and a nice addition to one’s observing list.

ESO 245-9 (Phoenix, open cluster, mag=9.3, size=14.0’, class=III1p):
This cluster is one of several open cluster discoveries during a study by the European Southern Observatory sites. Located about 21’ north of the mag 4.4 star Psi Phoenicis, it is a bit sparse in appearance, with its brightest member being mag 8.1 HD 11768 at its eastern edge. With about 15 stars ranging from the brightest down into the 13th magnitude range (plus even dimmer ones), it is not a showpiece nor is it significantly detached from the general field. But it can reveal a vague cluster-like appearance, particularly with a bit of aperture and darker skies. As this cluster may not appear on all charts or in object location databases, here is the position listed in Sky Tools 4: R.A. 01h53m16.0s; Dec -46°00'05".

[Graeme1858]

Thanks Alan, I look forward to hunting them down.

Graeme

[kt4hx]

Thanks Alan, I look forward to hunting them down.

Graeme

Thank you Graeme. Hopefully others will feel the same!

[kt4hx]

Here are some of my observing notes for this month's challenge objects. Most I have observed multiple times over the years, so I just randomly picked one instance for each object.

Northern Celestial Hemisphere:

Using my 12 inch at home seven years ago under our then Bortle 5 skies:

Collinder 463 (Cassiopeia, open cluster, mag=5.7, size=57.0’):
About 6° east of NGC 110 I easily found this large and bright cluster in the RACI. Though not significantly detached, it was still an interesting grouping, dominated by a triangle of stars with one of 8th at the apex, one of 9th at the northern corner and a nice pair (9th & 10th) at the other corner. Using 84x I counted around 20 stars total and noticed that inside the triangle the view was mostly devoid of stars. Overall, though easily seen, it wasn’t very memorable.


Using an ST120 refractor 12 years ago at a Bortle 4 location. I was using a Baader Hyperion zoom eyepiece for 30x to 75x:

Messier 76 / NGC 650 & 651 (Perseus, planetary nebula, mag=10.1, size=2.7’x1.8’, SBr=11.5):
Turning my attention northward, I moved into Perseus looking for M76, the Little Dumbbell Nebula. Starting at Theta Persei, I moved westerly through 64 and 65 Andromedae to Phi Persei. Slipping slowly to the south, I found the object next to a magnitude 6.5 star. The planetary was small, but bright. The O-III filter definitely helped, and brought out the whitish hourglass shape more (which would be the two lobes catalogued as separate objects).


This observation was with my 10 inch about 10 years ago from our then Bortle 5 backyard:

NGC 772 (Aries, spiral galaxy, mag=10.3, size=7.2'x4.3', SBr=13.8):

Going back to the ES 82 18mm (my mainstay DSO hunting EP), I headed to Aries seeking out the mag 10.3 spiral galaxy NGC 772. With a surface brightness of 13.8, it showed a dim oval with very slight brightening into the core at 69x. Increasing to 89x brightened it slightly, as did viewing it at 114x to 142x. However, no significant details were revealed.


Southern Celestial Hemisphere:

Using the 17.5 inch about three years ago at our dark site (typically Bortle 3) for both NGC 253 and 288

NGC 253 (Sculptor, barred spiral galaxy, mag=7.2, size=29.0’x6.8’, SBr=12.7):
This is one of my favorite galaxies and I wanted to warm up the eyeball on some sky-candy. Aiming the big scope at bright Beta Ceti (Diphda), I followed the trail of stars southward in the RACI finder to a flattened triangle of stars just inside the Sculptor border. Within this group I spotted the subtle glow of the bright galaxy in the finder. Taking a quick look at 110x (ES 82° 18mm) the field was filled with the vastness of this huge galaxy. Heavily mottled in appearance with a broadly brighter core, it is always a treat to spot with most any aperture.

NGC 288 Sculptor, globular cluster, mag=8.1, size=13.0’, class=10):
Less than 2° southeast of NGC 253 this globular is always easy to pick up. At 110x it was bright and somewhat large in angular presentation. At its lower declination and the poor seeing it was a bit diffuse with a very subtle central brightness in its core region. A few stars were resolved across its face, but its light was slightly smeared by the disturbed seeing conditions.

Using my ED80 refractor from a Bortle 5 to 6 location just south of the equator:

ESO 245-9 (Phoenix, open cluster, mag=9.3, size=14.0’, class=III1p):
Aiming the scope at mag 0.4 Alpha Eridani (Achernar), I then slipped slowly NNE for about 6° to Chi Eridani (mag 3.7). Here I turned due north for about another 5° to sweep up the red giant Psi Phoenicis winking at mag 4.4. This star was noticeably ruddy in tint and quite pretty at 26x. Just north of Psi, I noted the presence of mag 8.1 HD 11768 and what seemed to be just a slight bit of haziness next to it. Using 39x and 52x I picked up a second star of 9th magnitude, plus a sense of some dimmer stars just out of reach. Pushing up to 71x I did detect one or two more fleeting pinpricks of light, but could not hold them steadily. Using 107x there was definitely a total of four stars, and perhaps another one or two trying to poke through. Unfortunately, seeing wasn’t particularly good, which is fairly normal for this location as I am dealing with a marine layer. I saw a sketch of this object by noted South African deep-sky observer Magda Streicher, which was done with a 16 inch SCT, and with that aperture it is quite a nice rounded cluster. Not surprisingly, my attempt with only 80mm was unimpressive and the slightest shadow of its true beauty.

[Graeme1858]

I just put the northern targets into Stellerium to see how they would look in my camera. I've got my ASI224 planetary camera in at the moment waiting for a clear night for a go at Jupiter. So that would be an ideal FOV for the Little Dumbbell. I'll have to put the OAG back in the imaging train, something to get done while the rain persists!

NGC772 will need the ASI1600 and the focal reducer back in the telescope, so I'll do that after the Jovian opposition. NGC772 is an interesting shape and an excellent astrophotography target. Stellerium calls it the Fiddlehead Galaxy!

As for Collinder 463, that's going to be a binocular target. The Loch Ness Monster Cluster, according to Stellerium! I'll have a look and get you back with a count of visible stars, Friday looks like there might be some gaps between the clouds! Hopefully there will be a chance for a go at your Pegasus challenge while I'm at it!

Graeme

[kt4hx]

Sounds like a plan Graeme. Looking forward to the results!

[JSTAR0057]

This will be my first challenge, and I look forward to it. Do we post our work afterward?

[kt4hx]

Hi Jim and welcome both to our challenge and TSS. Absolutely, post your results. By sharing results, we can all learn from one another. Learning is one of the key elements of our hobby. As I am fond of saying, the more we learn the more fun we have, and the more fun we have, the more we learn. You can post them in this thread, whether it be a visual report, images or sketches. All those mediums are welcome. As you can see I am purely a visual observer, whereas Graeme does imaging. Good luck to you and look forward to your participation in the DSO challenge.

[Graeme1858]

So I settled back into the garden recliner with my 11 x 70s ready to go. After focusing on the disc of Jupiter and his pin prick points of light moons I was quite pleased to swiftly find the irregular rectangle of the four stars Cas40, Cas42, Cas48 and Cas50 recognised from the Cartes Du Ceil sky chart I had printed earlier. Initially there was nothing else to be seen in the rectangle except one faint star to the south. Then as my less than 20:20 eyes settled into the view I started to make out the faintest of dots in a curve where Collinder 463 is shown to be in Stellarium.

With a humidity level in the 90s my USBs were not playing the game so all hope of collimating my SCT and catching Jupiter in opposition went out of the window! And the GRS is transiting tonight with a Europa and shadow transit happening later too! So I think I'll abandon my planetary AP aspirations, put the ASI1600 back in, wait for the next clear night and go after the very lovely NGC772.

Graeme

[kt4hx]

So I settled back into the garden recliner with my 11 x 70s ready to go. After focusing on the disc of Jupiter and his pin prick points of light moons I was quite pleased to swiftly find the irregular rectangle of the four stars Cas40, Cas42, Cas48 and Cas50 recognised from the Cartes Du Ceil sky chart I had printed earlier. Initially there was nothing else to be seen in the rectangle except one faint star to the south. Then as my less than 20:20 eyes settled into the view I started to make out the faintest of dots in a curve where Collinder 463 is shown to be in Stellarium.

With a humidity level in the 90s my USBs were not playing the game so all hope of collimating my SCT and catching Jupiter in opposition went out of the window! And the GRS is transiting tonight with a Europa and shadow transit happening later too! So I think I'll abandon my planetary AP aspirations, put the ASI1600 back in, wait for the next clear night and go after the very lovely NGC772.

Graeme

Very good Graeme. What you describe happening with Cr 463 sounds about right. Initially one's attention is drawn to the brighter stars that frame the cluster's field. As we focus our attention into the area of the cluster, once our eyes adjust to the field, we then start to see the brighter stars of 8th to 10th mag in a bit of a disjointed curving line. Of course as aperture increases we start to pick up more and more of its contents, with many fainter stars dotting the field around the primary ones.

Looking forward to your image of NGC 772. You should have no difficulty picking up its elliptical companion, NGC 770 (mag 12.8) about 3.5' to the SSW. The pair are also catalogued as Arp 78.

[helicon]

Thanks for posting the monthly challenge Alan. Maybe if the weather can cooperate I will be able to get a session in. It's been far too long. I've figured out recently that the best observing spot around here is at the Marina by the lake, where the trees have been cleared.

[kt4hx]

Thanks for posting the monthly challenge Alan. Maybe if the weather can cooperate I will be able to get a session in. It's been far too long. I've figured out recently that the best observing spot around here is at the Marina by the lake, where the trees have been cleared.

Thank you Michael and we look forward to your observing notes for the objects that you can see from your latitude.

[John Baars]

As it kept on raining and clouds passing by, it was quite a challenge to sketch Collinder 463 in November in this environment. I had promised it
here viewtopic.php?t=32510 Look there post 14 for three origin drawings too . So I just kept on going. I took out my grab&go refractor several times during the past two weeks, but each time low-pressure areas and passing weather fronts threw a spanner in the works.

Yesterday evening the weather forecast promised a clear hour so I went out again. It lasted one hour precisely, although passing veil clouds occasionally caused a brief obstruction. During one such break, I rushed in to pick up some drawing supplies....couldn't find a pencil...then with a ballpoint. After finishing the sketch outside, it started raining again, just in time.....to get my gear wet on the outside. :-) Never mind, telescopes are not made from sugar. (not built like submarines either, for that matter)

I recognized Collinder 463 from the Skysafary app, the moment it appeared in my eyepiece. Found it through the NGC771 denomination star 50 Cas has, like described in the first post. The alt-az goto Memstar box of my grab&go refractor has a limited cataloque for individual stars. NGC771 can be found however, 50Cas or Collinder463 not.

Quite a nice starcluster. Due to the modest aperture and veils I could make out some 20 stars, but I am quite sure there are more. At least five nice pairs of doubles can be seen. It has some similarities with Stock 2, a fainter version of it. Have a look for yourself:

Click on the sketch for a sharper version

[helicon]

Nice work John. I also saw this in the Astronomy Sketching subforum

[Bigzmey]

Nice sketch and congrats on the VROD, John!

[Graeme1858]

Well I gave up on trying to capture Jupiter, so much for the Joy Bringer! I put the ASI1600MM back in to capture NGC772 for the November Challenge. It's the first clear night for ages but the humidity is high. After aligning and running the auto focus routine I slewed the telescope to NGC772 and attempted a plate solve only to discover that the camera failed to download. I tried a couple of different USB leads and connections to no avail. My best guess is the camera's not happy operating in 98% humidity. I'll fire it up again tomorrow during the day with lower humidity and see what happens.

Graeme

[kt4hx]

Very nightly done John. Your sketch is spot on, capturing the brightest swath of stars through the center of the cluster's field. Congrats on the VROD.

[Graeme1858]

After putting the ASI1600MM and EFW back in the telescope (again) we had a clear couple of hours forecast for last Wednesday so I took the opportunity to focus the guide camera and do a PHD2 calibration. That went well and as it turned out the sky stayed fairly clear with the odd cloud drifting by for another 90 minutes. So I slewed to NGC772, tried the NINA Manual Rotator function (brilliant!) and kicked off a capture sequence I've been putting together. I left it running until the 98% relative humidity caused a connection error. In future I'm going to shut everything down once humidity tops the low 90s.

I captured 14 x L and 7 x RGB @ 3 minutes each. A lot had satellite trails, a lot had a low star count due to cloud and some had wind gust star shapes. But I stacked them all anyway with the flats and flat darks captured the next day and processed quickly in Pixinsight. The image is a bit crap, NGC772 needs a lot more then 90 minutes integration but my guiding was ok so the calibration was ok and the shape of this interesting galaxy was captured, so I'll take that as a win.

Graeme

[helicon]

Great image of a challenge object Graeme! I think it's quite nice.