Although the weather has continued to be worse than normal, I was able to get out in March and image the night sky objects for the Hubble Anniversary Challenge for the month. More about the challenge can be found here.
This month’s objects contained a few star clusters. The first of which is Messier 67, a lovely open cluster in Cancer. It is also known as M67 or NGC 2682 and is sometimes called the King Cobra Cluster or the Golden Eye Cluster. It was discovered by Johann Gottfried Koehler in 1779. Estimates of its age range between 3.2 and 5 billion years. Distance estimates are likewise varied, but typically are 800–900 parsecs . It is well populated, almost appearing like a globular cluster, and is a paradigm study object in stellar evolution. I find it to be the most interesting looking object of this group.
Next up is the well-known Beehive Cluster, also an open cluster in Cancer. It is known as Praesepe (Latin for “manger”, “cot” or “crib”), M44, NGC 2632, or Cr 189. One of the nearest open clusters to Earth, it contains a larger population of stars than other nearby bright open clusters, holding around 1,000 stars. Under dark skies, the Beehive Cluster looks like a small nebulous object to the naked eye, and has been known since ancient times. Classical astronomer Ptolemy described it as a “nebulous mass in the breast of Cancer”. It was among the first objects that Galileo studied with his telescope. The distance to M44 is often cited to be between 160 and 187 parsecs (520–610 light years).
Age and proper motion coincide with those of the Hyades, suggesting they may share similar origins. Both clusters also contain red giants and white dwarfs, which represent later stages of stellar evolution, along with many main sequence stars.
Continuing the theme of open clusters, we continue to Messier 48, also known as NGC 2548. It is in the equatorial constellation of Hydra. It sits near Hydra’s westernmost limit with Monoceros, to the east and slightly south of Hydra’s brightest star, Alphard. This grouping was discovered by Charles Messier in 1771, but there is no cluster precisely where Messier indicated; he made an error, as he did with M47. Credit for discovery is sometimes given instead to Caroline Herschel in 1783.
M48 is visible to the naked eye under good atmospheric conditions. The cluster is located some 2,500 light-years from the Sun. The age estimated from isochrones is 400±100 million years, while gyrochronology age estimate is 450±50 million yearsr – in good agreement.
Finally, we come to Caldwell 48, also known as NGC 2775,. It is a spiral galaxy in the constellation Cancer. It is 67 million light-years away from the Milky Way. It was discovered by William Herschel in 1783. C48 belongs to the Antlia-Hydra Cluster of galaxies and is the most prominent member of the NGC 2775 Group, a small galaxy group in the Virgo Super-cluster, along with the Local Group. Other members of the NGC 2775 Group include NGC 2777 and UGC 4781. This object reminds us that Spring is known as “galaxy season” due to the prevalence of these distant objects in the night sky.
Due to the distance, this objects appears small in Seestar S50. It is the fuzzy object in the center of the photo.
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