#open clusters

The Annotated Galactic Center - November 11th, 1997.

Fox Fur and Christmas Tree's in the Constellation of the Unicorn

NGC 2264 in the constellation of Monoceros (The Unicorn) holds a beautiful reflective and emissions nebula which has a number of interesting shapes and features.

The open cluster of new born stars illuminates part of the Fox Fur nebula, while adding babbles to the Christmas Tree "Cone Nebula".

Hidden in the middle but not so visible in the image, is the snowflake cluster. Look at it in IR and it cut's through the dust and gas to review the obejct.

This is the Jewel Box! 💎💎💎

Located in the southern constellation Crux and visible to the naked eye, the Jewel Box contains a diverse variety of blue and red stars. The unique name of “Jewel Box” was given by John Herschel, standing out amidst the nearby dark nebula named the Coal Sack! 💫💫💫

This evening, I had a solid observing session. Given all the light pollution, and less than perfect skies, I’m still pretty darn proud of how these turned out. 

Mercury (photo 1-2): first photo was taken with iPhone XR using the NightCap app. Second was with the Canon M50. This little planet just happens to be my favorite. The length of a day on Mercury is about 59 Earth days, but a year is only 88 Earth days, making it the worst place for Monday to possibly exist. 

M44, the Beehive Cluster (partial): these bees aren’t bees. They don’t make honey, but they are known to host these sweet exoplanets known as Hot Jupiters; massive gas giants that closely orbit their home stars. 

M13, the Hercules Cluster: in the 1970’s, we beamed a ‘WYD?’ message towards this massive cluster, from the Arecibo Observatory, with our location and our deets. It’s unknown if M13 ever received our message; if so, it left us on ‘Read’. 

Arcturus: located in the constellation Böotes, its official abbreviation is Alpha Boo, which is kind of hilarious. The light emitted from this red giant is about 37 years old, and its the fourth brightest in the night sky.

Turns out, globular clusters are things that exist. They’re smaller than galaxies, but way more compact. Even though planets probably don’t exist in them, can you imagine living in one? It’d be daytime all the time. You probably wouldn’t be able to see anything outside your own cluster because of all the light interference.

Globular clusters are ancient. There’s a difference between those with collapsed cores vs. non-collapsed cores, but I can’t tell it apart. Within the cores stars can be as close as our sun and Pluto; hence a lot of binary systems.

Messier 36,37&38

What does a pinwheel, salt & pepper and a starfish have in common ? They are all informal names for open clusters catalogued by Charles Messier in 1771-81.

Above M36, the Pinwheel cluster, similar in many ways with the more famous Pleaides cluster, but at 4,000+ light years from us, much further away.

There is some evidence of continued star formation occurring, above a protostar appears to leave a trail as the star moves.

M37 The salt & pepper cluster is clear to how it got it's name, the abundance of evolved stars alongside those still on the main sequence have given it the appearance of a mix.

It's a similar distance to M36 and not so far away either.

Along with all the clusters in this post, it is opposite to the galactic centre from Earth's perspective, placing it on the outer edges of our galaxy.

Finally the starfish M38. around 500 light years closer than the other two, but of a similar age.

It contains a number of stars moving off the main sequence, including the brightest in the cluster, and many large hot blue giants.

It goes to show, even when we look out to the edges of our galaxy, there are many amazing things to see.

M9, M10 & M11

Messier 9 & 10 are globular clusters, ancient objects at 12 and 11.3 billion years old respectively.

Both clusters are in the constellation of Ophiuchus, although at different distances, with M10 being much closer at 17,000 light years, while M9 is further out at 25,800 light years.

Globular clusters tend to follow eccentric orbits around the galaxy, moving out of the galaxy plane and into the halo, and then returning back through the galaxy and out the other side.

M11 may look like a globular cluster, but it's an open cluster, the difference being it's formed in a nebula and often much more recently.

It's similarity to globular clusters however is mostly because it is one of the most massive and compact open clusters known, but the colour is a give-away, young star clusters tend to visibly be dominated by blue giant stars, they don't last too long in the scheme of things, and then return much dust and gas back into the environment for more stars to form from.