TSS Monthly DSO Challenge for December 2023
Posted: Fri Dec 01, 2023 3:06 am
Here we are with the last month of the year, and full of holiday cheer! We are also celebrating the richness of the late autumn/early winter sky for us northerners. Our southern friends also share in this richness as they move from spring into summer. For all of us, we look forward to enjoying some time with mighty Orion, but for the Challenge, we will wait until January to delve into its riches. In the meantime, for the northerners among us, we shall visit the celestial giraffe, Camelopardalis, for a fine asterism and open cluster duo. Then we finish out in Perseus in pursuit of an emission nebula, and finally a brighter galaxy.
Heading down south we will visit Fornax to seek out a brightasterism , a brighter member of the Fornax Galaxy Cluster and a fine planetary nebula. We wind up this month’s Challenge in Eridanus for another brighter galaxy that is a curious object indeed. I hope you all enjoy this month’s foray into the depths of the universe.
Northern Celestial Hemisphere
NGC 1502 (Camelopardalis, open cluster, mag=6.9, size=20.0’, class=II3p):
Kemble 1 (Camelopardalis,asterism , mag brightest star=5.0, size~3.0° long):
You get a twofer withNGC 1502. This cluster sits near the end of the famous asterism , Kemble 1, more familiarly known as Kemble’s Cascade. In fact, the asterism is more prominent in wide field views, appearing as a very noticeable string of stars flowing or cascading northwest to southeast. The southeastern end of the flowing stream of stars forks, with the northern branch leading directly to NGC 1502. The cluster presents an illusory pooling of stars at the end of the stream-like flow of the asterism . They make a curious and beautiful pairing that truly catches the eye.
NGC 1502 is not a huge, showy cluster on the order of some in Cassiopeia or Perseus. However, it is no slouch either. For double star enthusiasts, there are a couple of multiple stars residing in the heart of the cluster’s field as well, STF-484 and STF-485.I find the cluster a bright and well detached clump of 20 to 30 brighter stars ranging from 5th to 10th magnitude. The number one will perceive depends of course upon your sky quality and aperture . Discovered in 1787 by William Herschel, he noted it as "a cluster of stars, pretty rich and considerably compressed.”
Theasterism which seems to feed into the cluster, like a brook into a pool, is lengthy and prominent through a wide-field eyepiece or binoculars. Its brightest star is mag 5.0 HD 24479 not quite halfway from the northwestern end of the line toward the southeast. The asterism splits at its southern end with a flow of stars going east to the cluster, and a second dribble of suns to the south. Overall it is nearly 3° in length and makes a fine view under a cool November sky. This particular stellar grouping was named after Father Lucian Kemble by Walter Scott Houston, the original author of the Deep Sky Wonders in Sky &Telescope. Kemble wrote a letter to Houston about the asterism in which he described it appearing in 7x35 binoculars as "a beautiful cascade of faint stars tumbling from the northwest down to the open cluster NGC 1502.” In honor of Father Kemble he titled the group as Kemble’s Cascade in one of his Deep Sky Wonders columns published in 1980.
NGC 1491 (Perseus, emission nebula, mag=unk, size=9.0’x6.0’):
This nebula is located in the northeastern portion of Perseus, just over 1° NNW of mag 4.3 Lambda Persei. While it’s angular size is typically listed as large as around 9’x6’, its visual extent will likely be smaller. Imagers of course can often draw out more of its dimmer outer portions. The complex is illuminated by the mag 11.2 star BD +50 00886. Visually, it responds very nicely to either a narrow-band nebula filter or an O-III filter. As with most nebulae of this type, using a filter will definitely benefit the observer by boosting its contrast against the background sky.
I’ve seen various nicknames attributed to this nebula, including the Fossil Footprint, Little Pacman and the Wild Boar Nebula. It was discovered by William Herschel in 1790 and in his shorthand notation he flagged it as “vB” (very Bright). Though its visual magnitude is not listed anywhere that I’ve checked, it is considered one of the brighter members of the emission nebula category. It is a particularly a fine target for imagers to see how much detail they can tease out of its structure. So check it out and see how much of its glow you can pick up across the 10,000 light year distance between it and us here on our home planet.
NGC 1023 (Perseus, barred lenticular galaxy, mag=9.4, size=7.4’x2.5’, SBr=12.3):
Remaining in Perseus, but this time moving to the southwestern portion near the border with Andromeda, we now pursue this barred lenticular galaxy. In terms of galaxies, this one is fairly bright, with a higher surface brightness. Appearing as a thin oval glow, it appears pretty evenly illuminated across its disk. Discovered in 1786 by William Herschel, he described it as being "extremely bright, much extended, a very bright nucleus.” Fairly large in angular size for a galaxy, it lies about 30 million light years distant, and is the namesake of theNGC 1023 Group, which along with our Local Group, is part of the Local Super Cluster.
This galaxy is also catalogued as Arp 135 and sorted into the section for "Galaxies with Nearby Fragments." The fragment being referred to is actually another galaxy at its eastern tip. Sometimes listed asNGC 1023A, it is more properly catalogued as PGC 10139. This companion galaxy is a real challenge for the keen-eyed observer and makes an interesting add-on target for the imager.
Southern Celestial Hemisphere
Harrington 2 (Fornax,asterism , mag brightest star=5.7, size=53.0’):
This bright grouping lies in the western section of the famous Fornax Galaxy Cluster (Abell S0373). It is named for noted observer and author, Phil Harrington, and is dominated by three unrelated stars that share the same stellar designation, Chi Fornacis. These are Chi1 at mag 6.4, Chi1 at mag 5.7 (brightest star of the group) and Chi3 at mag 6.5. These three stars along with mag 7.2 HD 21852 at the eastern edge of theasterism ’s field, form a flattened diamond pattern aligned roughly east-west. In the roughly 53.0’ field, there are about 10 stars of 9th magnitude and brighter, with many more of 10th and dimmer magnitude. But it is the brighter stars that standing out and make this asterism readily apparent.
While heading into the Fornax Galaxy Cluster, take a moment to view this pretty little grouping. A little bonus object within its field is the mag 12.3 lenticular galaxyNGC 1336, which is located about 12.5’ west of Chi2 Fornacis.
NGC 1316 (Fornax, barred lenticular galaxy, mag=8.5, size=11.0’x7.2’, SBr=13.0):
This object is famously known as the radio galaxy Fornax A, and due to its “disturbed” nature it also appears in Dr. Halton Arp’s Catalogue of Peculiar Galaxies as Arp 154. Located almost 1.5° SSW of Chi1 Fornacis, it is the brightest galaxy within the Fornax Cluster. This object was discovered by James Dunlop in 1826 during his sky surveys at Parramatta, New South Wales.
Visually, it presents a somewhat large and bright rounded disk. The observer should note a compact and brighter core region within its envelope as well. Be sure to keep an eye out for magnitude 11.0 barred spiralNGC 1317 immediately north of NGC 1316. This object was also discovered by Dunlop at the same time he discovered its more prominent neighbor. Both are located in the southwestern quadrant of the Fornax Galaxy Cluster. In fact, one should take some time farming the cluster’s field to see just how many of its members they can discern.
NGC 1360 (Fornax, planetary nebula, mag=9.4, size=7.7’x5.3’, SBr=13.2):
Staying in Fornax, we now shift our attention nearly 10° north of the heart of the Fornax Cluster toward the border with Eridanus. This planetary nebula has a long and winding discovery trail. It was first seen in 1859 by Lewis Swift who did not report it until 1885. It was independently discovered in 1861 by Wilhelm Temple (who likewise failed to report the object until years later), in 1868 by August Winnecke and finally in 1879 by Eugen Block. Because both Swift and Temple delayed notification of their discovered, Winnecke was originally credited, but this was eventually amended.
Located just over 5.5° northeast of mag 3.8 Alpha Fornacis, this large oval disk is nicknamed the “Robin’s Egg Nebula” for its noticeably shape and pale bluish tint. Typical of planetary nebulae, it responds well to both a narrow-band nebula filter and particularly to an O-III line filter. Fairly bright for aPN , with increasing aperture and magnification, it can reveal some uneven brightness in the area surrounding the very noticeable mag 11.3 central star. It is a truly curious object and the best non-galactic treat within the celestial furnace.
NGC 1291 (Eridanus, barred lenticular ring galaxy, mag=8.5, size=11.0’x9.5’, SBr=13.3):
We now turn SSW about 4° fromNGC 1316, which brings us into the realm of Eridanus the river. This bright galaxy is located close to the middle of a very large triangle of three brighter stars formed by mag 2.9 Theta Eridani, mag 4.3 HD 20794 and mag 4.6 HD 22663. Originally discovered by James Dunlop in 1826, but his position was off by about 4’ to the ESE. In 1836 John Herschel, during his southern sky scans from South Africa also observed this object and it later found its way into the NGC as NGC 1269. However, Dunlop is rightfully credited with discovery.
This beautiful object contains a prominent bar, as well as an outer ring, which is prominent in deep images and appears quite ethereal. Visually in amateur scopes one should be able to pick out the prominent central bar region as a broad and elongated brightness within a very dim and diffuse outer halo. Look for the mag 12.5 foreground star less than 2’ north of the center of the galactic disk, which Dunlop noted in his discovery notes. Lying at only about 33 MLY distant, it is relatively close to us (in astronomical terms), and was cited as an example of a “transitional galaxy” the Galaxy Evolution Explorer team at NASA in 2007.
There you have it my friends. As always your contributions observing reports, sketches and/or images of any of these objects is encouraged and very welcome. You don’t have to be an expert visual observer, sketcher or imager to post your results. We enjoy everyone sharing of their experiences, as we can all learn from our shared interest and activity in the hobby. So good luck and get on out there under the night sky.
Heading down south we will visit Fornax to seek out a bright
Northern Celestial Hemisphere
Kemble 1 (Camelopardalis,
You get a twofer with
The
This nebula is located in the northeastern portion of Perseus, just over 1° NNW of mag 4.3 Lambda Persei. While it’s angular size is typically listed as large as around 9’x6’, its visual extent will likely be smaller. Imagers of course can often draw out more of its dimmer outer portions. The complex is illuminated by the mag 11.2 star BD +50 00886. Visually, it responds very nicely to either a narrow-band nebula filter or an O-III filter. As with most nebulae of this type, using a filter will definitely benefit the observer by boosting its contrast against the background sky.
I’ve seen various nicknames attributed to this nebula, including the Fossil Footprint, Little Pacman and the Wild Boar Nebula. It was discovered by William Herschel in 1790 and in his shorthand notation he flagged it as “vB” (very Bright). Though its visual magnitude is not listed anywhere that I’ve checked, it is considered one of the brighter members of the emission nebula category. It is a particularly a fine target for imagers to see how much detail they can tease out of its structure. So check it out and see how much of its glow you can pick up across the 10,000 light year distance between it and us here on our home planet.
Remaining in Perseus, but this time moving to the southwestern portion near the border with Andromeda, we now pursue this barred lenticular galaxy. In terms of galaxies, this one is fairly bright, with a higher surface brightness. Appearing as a thin oval glow, it appears pretty evenly illuminated across its disk. Discovered in 1786 by William Herschel, he described it as being "extremely bright, much extended, a very bright nucleus.” Fairly large in angular size for a galaxy, it lies about 30 million light years distant, and is the namesake of the
This galaxy is also catalogued as Arp 135 and sorted into the section for "Galaxies with Nearby Fragments." The fragment being referred to is actually another galaxy at its eastern tip. Sometimes listed as
Southern Celestial Hemisphere
Harrington 2 (Fornax,
This bright grouping lies in the western section of the famous Fornax Galaxy Cluster (Abell S0373). It is named for noted observer and author, Phil Harrington, and is dominated by three unrelated stars that share the same stellar designation, Chi Fornacis. These are Chi1 at mag 6.4, Chi1 at mag 5.7 (brightest star of the group) and Chi3 at mag 6.5. These three stars along with mag 7.2 HD 21852 at the eastern edge of the
While heading into the Fornax Galaxy Cluster, take a moment to view this pretty little grouping. A little bonus object within its field is the mag 12.3 lenticular galaxy
This object is famously known as the radio galaxy Fornax A, and due to its “disturbed” nature it also appears in Dr. Halton Arp’s Catalogue of Peculiar Galaxies as Arp 154. Located almost 1.5° SSW of Chi1 Fornacis, it is the brightest galaxy within the Fornax Cluster. This object was discovered by James Dunlop in 1826 during his sky surveys at Parramatta, New South Wales.
Visually, it presents a somewhat large and bright rounded disk. The observer should note a compact and brighter core region within its envelope as well. Be sure to keep an eye out for magnitude 11.0 barred spiral
Staying in Fornax, we now shift our attention nearly 10° north of the heart of the Fornax Cluster toward the border with Eridanus. This planetary nebula has a long and winding discovery trail. It was first seen in 1859 by Lewis Swift who did not report it until 1885. It was independently discovered in 1861 by Wilhelm Temple (who likewise failed to report the object until years later), in 1868 by August Winnecke and finally in 1879 by Eugen Block. Because both Swift and Temple delayed notification of their discovered, Winnecke was originally credited, but this was eventually amended.
Located just over 5.5° northeast of mag 3.8 Alpha Fornacis, this large oval disk is nicknamed the “Robin’s Egg Nebula” for its noticeably shape and pale bluish tint. Typical of planetary nebulae, it responds well to both a narrow-band nebula filter and particularly to an O-III line filter. Fairly bright for a
We now turn SSW about 4° from
This beautiful object contains a prominent bar, as well as an outer ring, which is prominent in deep images and appears quite ethereal. Visually in amateur scopes one should be able to pick out the prominent central bar region as a broad and elongated brightness within a very dim and diffuse outer halo. Look for the mag 12.5 foreground star less than 2’ north of the center of the galactic disk, which Dunlop noted in his discovery notes. Lying at only about 33 MLY distant, it is relatively close to us (in astronomical terms), and was cited as an example of a “transitional galaxy” the Galaxy Evolution Explorer team at NASA in 2007.
There you have it my friends. As always your contributions observing reports, sketches and/or images of any of these objects is encouraged and very welcome. You don’t have to be an expert visual observer, sketcher or imager to post your results. We enjoy everyone sharing of their experiences, as we can all learn from our shared interest and activity in the hobby. So good luck and get on out there under the night sky.