Monthly Notes

February 1, 2024

This time of the year is for the constellation Orion, which is prominent DUE SOUTH, about half way up the sky. Orion, the Hunter, is one of the most easily recognized constellations in the whole sky because it is basically a rectangle with tilted ends consisting of four bright stars! However, what makes Orion stand out even more are its three Belt stars in the middle of the “rectangle”—somewhat angled. They are fairly bright, form a short line and are equally spaced. Below the three Belt stars is the well-known and bright Orion Nebula, the brightest nebula that can be seen from the Northern Hemisphere (need a small telescope). The three Belt stars point roughly (downward) to Sirius, the brightest star in the whole sky. Now, the upper left corner star of the “rectangle” is the famous reddish Betelgeuse which is the 10th brightest star in the whole sky. It is a massive supergiant star that will one day explode as a supernova.

Ken’s Astrophoto of the Month • February 2024


Since I am talking about the constellation of Orion this month (see above), it is most appropriate to show an image of the famous Orion Nebula that I took a few months ago. I will be totally upfront and tell you that this is a very poor image of the nebula. I did not process it at all and it is very overexposed, as you can see by the large whitish area around the middle. Also, I positioned the nebula near the edge of the sensor where the images of stars get elongated. The Orion Nebula is the brightest nebula that can be seen from the Northern Hemisphere. However, like most Deep Sky Objects, you need relatively dark skies and when the Moon is not bright to see it the best—a 4-inch diameter telescope is more than adequate to see details. Housed within that overexposed area (something that does not happen when viewing with a telescope) are four stars forming a trapezoid. Appropriately, it is called the Trapezium. These four stars are vey young, were born out of the Orion Nebula and are so energetic that they are stimulating this hydrogen gas cloud to shine brightly. The pinkish coloring is real and can sometime be seen.

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There are 110 “M” catalogue numbers from Charles Messier's catalogue of objects that he compiled in the mid to late 1700s. He was the first person to catalogue clusters of stars, various types of nebulae, supernovae remnants and galaxies—a type of catalogue that was lacking during his time.

The NGC catalogue was compiled in the late 1800s and lists over 13,000 objects. Basically, it lists all objects (clusters of stars, various types of nebulae, supernovae remnants and galaxies) visually visible with a telescope around 20 inches in diameter at a dark location.

The Pleiades or Seven Sisters

The Pleiades sorta looks like a little dipper. It is small in the sky and initially looks like a fuzzy spot to the eyes. Great in binoculars.

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