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  • Luke

Whats up this Fall!

Here's a list of what you will see on an AstroTour this Fall!

The Double Cluster [in Perseus] (back up open clusters: M39[Cyg], M11[Sco], M6[sco], M21[Sag])


The Double Cluster


  • Open cluster

  • Can be seen as a mist, cloud, or fog with the naked eye. Kinda like a little bright drip of the milky way.

  • “Town of stars, just down the road” aka: Thousands of stars, hundreds of light years away (actual distance 7,000ly, and about 18,000 stars).

  • like little towns of stars just down the road like Lyons, Jamestown, or Nederland. Hundreds of light years sounds far and it is a mind boggling large distance but compared to the globular clusters and galaxies (thousands and millions of light years away respectfully) we look at, it is just down the road.

  • What does it look like to you? I hear some say an arrow head, some say, bees, butterflies, etc. some just say “stars”

  • Try to count/estimate how many stars you see it should be at least ~70 so this might take a while

  • Open Clusters are like teenage stars. They were likely all fourmed closer together, in the same star forming nebula (or more simply “stellar nursery”), and are now spreading out leaving the nursery and going their own ways in our galaxy

  • Total mass is about 20,000 times that of our sun

  • Age of the cluster is about 100 million years old

  • I think of this like young or *teenage* stars. Stars get to be billions of years old, our sun is 4.6 billion years old


Location of Double Cluster near the W of Cassiopeia


M13 - Hercules Cluster [in Hercules] (back up globular clusters: M4 [Sco], M5 [Ser], M22 [Sag], M3 [CVen], M92 [Her])


M13 - Hercules Cluster

  • Globular cluster

  • “city of stars” Thousands of light years away, Millions of stars (actual distance 23 thousand ly away, about a million stars) like far away a mega city of stars like NY, LA, Madrid, Tokyo. thousands of light years away is far compared to the open clusters we look at but it’s still in our galaxy and really close compared to the galaxies we look at.

  • We’re seeing how it looked 23 thousand years ago because it’s 23 thousand light years away but little has probably changed as these clusters are ancient.

  • M13 is twice the age of our solar system at 11.6 billion years old

  • M13 is about 84 light years across and if our solar system was in it we would have about 500 times more stars in our sky as it’s so dense with stars

  • Can’t count all the stars, many stars can be seen on the edge of it but as you get closer to the center core it becomes a fuzzy glob of star light from millions of stars shining together.

  • What does it look like to you? I usually get spider webs, or shards of glass. Sometimes I hear spilled salt or sugar. My favorite is a girl scout who said it looked like a dandelion seed ball just before you blow it out. My least favorite is a nurse who told me it looks like COVID in a microscope.

  • On really dark moonless nights you can just barely make it out with the naked eye as a faint fuzzy star if you have really good eyes

  • Easily found in binoculars, first look for the “keystone” of hercules (Vega in the summer triangle points at the key stone) Then it’s about halfway in between the western most two stars of the keystone (see chart on other side).

  • Discovered in 1715

  • Brightest and richest of all of the globular clusters in the northern hemisphere. (omega centauri, and 47 Tuc are only two that are brighter but they can only be seen in the southern hemisphere)

  • We usually show at least two globular clusters to show how different the globular clusters can look. I think M13 looks more like an american city (like dallas/ft.worth) with sprawling suburbs, where M92, and some of the others, look more like a european city with a dense urban core (like Madrid or Tokyo).

  • In 1974 we sent a high powered radio signal called the arecibo message (named after the now defunct arecibo observatory that sent it) to M13 potentially telling any life in M13 about life on earth. It will still take over 23 thousand years for the message to reach M13 and another 23 thousand years for a response (if any) to come back

  • Globular cluster’s origin is a mystery, usually said to be old cores of galaxies that our galaxy has run into and consumed/captured. This has been called into question as there’s a nebula (the tarantula nebula) in a satellite galaxy of ours (the large magellanic cloud, unfortunately only seen in the southern hemisphere) that seems to be forming a globular cluster. The mystery being that all globular clusters we see (even in other galaxies) are made up of super old stars, except for one; right on our doorstep we see what looks like it’s one being born. So if you can think of a story for why that would be, I would love to hear it and I would love even more to be cited on your paper when you write it ;)


Location of M13 - Hercules Cluster

M81 - Bode’s “Nebula” {galaxy} [in the big dipper (UMa)] and M31Andromida Galaxy [in Andromeda] (back up galaxies: M82 (whirlpool) [UMa], M51 (sunflower) [CVn], M104 [vir], M64 [com], M63 [CVn], M87 [vir], M86 [vir], M66 [leo]


M81 - Bode’s “Nebula”

M31 Andromeda Galaxy

  • Galaxy

  • Billions of stars, Millions of years away

  • Looks like a faint fuzzy thing, can no longer see individual stars (too many stars too far away) but only see millions of stars shining together in a luminous cloud.

  • 12 million lightyears away(Bodes) 2.7 million lightyears away(Andromeda), the light (photons) you’re seeing left that galaxy 12 million years ago and has been traveling all the way through space for 12 million years to land in your telescope and interact with your retina so you are having a physical interaction with a galaxy 12 million light years away… not bad for a “faint fuzzy” thing

  • 70,000 light years across(bodes) 152,000ly across (Andromeda)

  • The furthest away we will look in the telescopes much farther than the globular or open clusters

  • Everything we look at tonight exists a multitude of times in this other galaxy. Bode's galaxy has about 250 billion stars, Andromeda has ~1 trillion. each of those stars just like our sun likely has many planets, and many of those planets have multiple moons, it has thousands of nebulae, thousands of open clusters, and hundreds of globular clusters.

  • It’s called bode’s “nebula” because before the 1920s we didn’t even know other galaxies were out there and everything astronomers saw that were faint and fuzzy in a telescope were called “nebula”. It wasn’t until Edwin Hubble using the biggest telescope at the time looked at this galaxy and about a dozen others and realized that they were other galaxies. It wasn’t until the 1930s that other galaxies became widely accepted as astronomers had thought our galaxy to be the entire universe at the time, and Hubble was saying our galaxy was just one of many. Now NASA has cataloged over two trillion galaxies (that’s just what they’ve counted, we know there’s more), so less than 100 years ago astronomers thought the universe was half a trillionth of what we know it to be today. Makes you wonder what the next 100 years holds for us

  • There is a black hole in the middle of M81 that is 70 million times the mass of our sun

  • If there’s extra time we show M82 as well it’s right next to it and shows how different the galaxies can look if you’re looking edge on (M82) or more of a top view of the full disk (M81)

  • M81 and M82 collided a few hundred million years ago causing M82 to be deformed.

  • M81 is 150,000 light years away from M82 right now

  • M81 and M82 are still interacting gravitationally this has pulled some gasses from M81 to M82 letting M82 form more stars

  • In zoomed out binoculars you can get M82 and M81 in the same field of view.

  • Can’t be seen with the unaided eye but easily seen in decent binoculars

  • Can be found by using the diagonal stars of the vessel of the big dipper as a pointer (see chart)

  • Discovered in 1774