TSS Monthly DSO Challenge for March 2023
Posted: Sun Mar 03, 2024 3:06 pm
Welcome to a new month, which means it is again time for another edition of the TSS DSO Challenge. This month I have for your pursuit a trio of objects in the northern celestial hemisphere and three for the southern celestial hemisphere. Depending upon where one lives relative to the terrestrial equator of course, some may be able to observe some or all of those from the opposite hemisphere.
For our northern members, I will be highlighting a trio of star clusters, with open clusters in Cancer and Canis Minor, plus a very distant globular cluster in Lynx. Our southern friends will have a similar recipe for this month, with an open cluster in both Carina and Puppis, plus a globular in Puppis. I hope you enjoy adding these objects to your observing and/or imaging plans. We all look forward to hearing (or seeing) your results as you spend some time communing with the night sky in pursuit of these interesting and worthy targets. Have fun my friends and enjoy your time spent under the stars.
(Northern Celestial Hemisphere)
Messier 67 / NGC 2682 (Cancer, open cluster, mag=6.1, size=25.0’x25.0’):
This is an amazingly beautiful open cluster. While it tends to be overshadowed byMessier 44 to its north, this cluster truly holds its own. More compact than M44, it is much more suited to telescopic observation. Containing a vast number of stars, it is a dizzying array of lines and curves of stellar points, with countless double stars within its field. There are even some lanes of lower star density that may stand out to your eye, depending upon your aperture and optical acuity.
This beauty was first discovered by German observer Johann Gottfried Koehler at some point before 1779. CharlesMessier independently discovered it on April 6, 1780. William Hershel observed it using his 18.7 inch reflector in 1784, and he described it as "a most beautiful cluster of stars; not less than 200 in view." Spend some time on this object and immerse yourself in its beauty.
NGC 2394 (Canis Minor, open cluster, mag=8.7, size=8.0’):
We now move from the stunning beauty of M67 to the rather obscurity of this William Herschel discovery, from 1785. He described it as "a cluster of very coarse scattered large stars, they form a cross and extend over a large space; not rich." In modern references, it is most often designated as anasterism . While not a standout object, I find it a curious one. With eight stars ranging from 9th to 11th magnitude, to my eye it looks like an “S” shape, with dimmer stars scattered haphazardly around the field. Give this one a try and see what you can come up.
NGC 2419 (Lynx, globular cluster, mag=10.3, size=4.6’, SBr=13.4, class=2):
We now come to what was nicknamed the “Intergalactic Wanderer” because it was once thought to be a free floating globular outside of our gravitational influence. Though that thinking was eventually disproven and was determined to be a Milky Way globular cluster, just at a great distance. William Herschel also discovered this object, on the last day of the year in 1788. Observed with his 18.7 inch telescope he noted it as a "considerably bright, round, very gradually much brighter middle, about 3' diameter."
Despite Sir William calling it “bright”, most will find it is anything but. Small and compressed, its center may show some brightness surrounded by a very small dimmer outer halo. But overall it will most likely appear dim and fuzzy, unless you have largeraperture , which may reveal some graininess. It lay in line with two 7th magnitude field stars, forming an east-west line with them. The cluster is the eastern most of the three, and should have a slightly fuzzy appearance as compared to the stars to its west.
Southern Celestial Hemisphere
NGC 2516 (Carina, Open Cluster, mag=3.8, size=29.0’):
The huge constellation of Argo Navis, depicting the famed ship piloted by Jason and his Argonauts, was eventually dived into three sections. Carina represents the keel of that ship. It is a treasure trove of celestial objects, in particular open clusters. This beautiful group of stars was discovered by Nicolas-Louis de Lacaille during his survey of stars in 1751-52 during his expedition to the Cape of Good Hope.
Also known as the Southern Beehive Cluster, this object is large and bright. Not overly difficult with the naked eye, it most certainly can be seen with binoculars. However, its true richness comes alive through a telescope. Its stars are scattered across the large field, with numerous doubles, arc and lines being seen. Located just over 3° southwest of bright mag 1.8 Epsilon Carinae (Avior), it is truly a fine cluster to behold.
NGC 2477 (Puppis, open cluster, mag=5.8, size=27.0’):
This fine cluster is located in another fragment of the original Argo Navis constellation, Puppis, which represents the poop deck of a ship. Located a little over 2.5° northwest of mag 2.1 Zeta Puppis (Naos), it lay only about 20’ north of the mag 4.5 variable QZ Puppis. A visually beautiful cluster, it is very rich in mag 11 to 13 stars, with easily over 200 within its field, with a persistent background haziness of unresolved suns.
This cluster is another discovery credited to Nicolas-Louis de Lacaille during his time at the Cape of Good Hope. It was also observed multiple times by James Dunlop (Paramatta, Australia) in the mid-1820s, as well as by John Herschel (Cape of Good Hope) in the mid-1830s. Herschel’s second observation of the cluster resulted in this notation in his journal: "a very beautiful large cluster, very rich; stars nearly equal and 12th mag, gradually brighter in the middle, not much compressed in the middle; more than fills the field. (N.B. It is visible in the finder of the equatorial, and in the telescope of that instrument appears as a fine cluster."
NGC 2298 (Puppis, globular cluster, mag=9.3, size=5.0’, class=6):
Remaining on the “poop deck”, we now pursue this globular cluster as our final object this month. Located in the northwest corner of Puppis, it is located about 3.5° south of mag 4.0 Kappa Canis Majoris. This object was discovered by James Dunlop in 1826, he noted it as "a pretty bright round nebula, 3' or 4' diameter, moderately condensed to the centre. This is resolvable into stars."
Small and somewhat dim, this globular may appear as a diffuse little globe, clearly non-stellar to the eye. Asaperture increases one may begin to pick up hints of a brighter, more condensed core and even some granular texture, particularly from darker areas. While certainly not a showpiece cluster visually it is still not an overly difficult object, and certainly makes a fine target for the imager. Though lower in the sky, it can be seen from the southern portions of the northern mid-latitude spatial region.
I hope that you enjoy adding these objects to your observing/imaging plans. While I do highlight some well know objects for your pursuit, I also like to add in some lesser known, off the beaten trackDSOs . So good luck with your endeavors, and as always, let us know how you fare with this month’s targets. We are all here to learn, share and grow as astronomy hobbyists. Our shared interest in the night sky and its wonders are the glue that holds our community and family together here at TSS !
For our northern members, I will be highlighting a trio of star clusters, with open clusters in Cancer and Canis Minor, plus a very distant globular cluster in Lynx. Our southern friends will have a similar recipe for this month, with an open cluster in both Carina and Puppis, plus a globular in Puppis. I hope you enjoy adding these objects to your observing and/or imaging plans. We all look forward to hearing (or seeing) your results as you spend some time communing with the night sky in pursuit of these interesting and worthy targets. Have fun my friends and enjoy your time spent under the stars.
(Northern Celestial Hemisphere)
This is an amazingly beautiful open cluster. While it tends to be overshadowed by
This beauty was first discovered by German observer Johann Gottfried Koehler at some point before 1779. Charles
We now move from the stunning beauty of M67 to the rather obscurity of this William Herschel discovery, from 1785. He described it as "a cluster of very coarse scattered large stars, they form a cross and extend over a large space; not rich." In modern references, it is most often designated as an
We now come to what was nicknamed the “Intergalactic Wanderer” because it was once thought to be a free floating globular outside of our gravitational influence. Though that thinking was eventually disproven and was determined to be a Milky Way globular cluster, just at a great distance. William Herschel also discovered this object, on the last day of the year in 1788. Observed with his 18.7 inch telescope he noted it as a "considerably bright, round, very gradually much brighter middle, about 3' diameter."
Despite Sir William calling it “bright”, most will find it is anything but. Small and compressed, its center may show some brightness surrounded by a very small dimmer outer halo. But overall it will most likely appear dim and fuzzy, unless you have larger
Southern Celestial Hemisphere
The huge constellation of Argo Navis, depicting the famed ship piloted by Jason and his Argonauts, was eventually dived into three sections. Carina represents the keel of that ship. It is a treasure trove of celestial objects, in particular open clusters. This beautiful group of stars was discovered by Nicolas-Louis de Lacaille during his survey of stars in 1751-52 during his expedition to the Cape of Good Hope.
Also known as the Southern Beehive Cluster, this object is large and bright. Not overly difficult with the naked eye, it most certainly can be seen with binoculars. However, its true richness comes alive through a telescope. Its stars are scattered across the large field, with numerous doubles, arc and lines being seen. Located just over 3° southwest of bright mag 1.8 Epsilon Carinae (Avior), it is truly a fine cluster to behold.
This fine cluster is located in another fragment of the original Argo Navis constellation, Puppis, which represents the poop deck of a ship. Located a little over 2.5° northwest of mag 2.1 Zeta Puppis (Naos), it lay only about 20’ north of the mag 4.5 variable QZ Puppis. A visually beautiful cluster, it is very rich in mag 11 to 13 stars, with easily over 200 within its field, with a persistent background haziness of unresolved suns.
This cluster is another discovery credited to Nicolas-Louis de Lacaille during his time at the Cape of Good Hope. It was also observed multiple times by James Dunlop (Paramatta, Australia) in the mid-1820s, as well as by John Herschel (Cape of Good Hope) in the mid-1830s. Herschel’s second observation of the cluster resulted in this notation in his journal: "a very beautiful large cluster, very rich; stars nearly equal and 12th mag, gradually brighter in the middle, not much compressed in the middle; more than fills the field. (N.B. It is visible in the finder of the equatorial, and in the telescope of that instrument appears as a fine cluster."
Remaining on the “poop deck”, we now pursue this globular cluster as our final object this month. Located in the northwest corner of Puppis, it is located about 3.5° south of mag 4.0 Kappa Canis Majoris. This object was discovered by James Dunlop in 1826, he noted it as "a pretty bright round nebula, 3' or 4' diameter, moderately condensed to the centre. This is resolvable into stars."
Small and somewhat dim, this globular may appear as a diffuse little globe, clearly non-stellar to the eye. As
I hope that you enjoy adding these objects to your observing/imaging plans. While I do highlight some well know objects for your pursuit, I also like to add in some lesser known, off the beaten track