Messier Monday: A High-Flying Cluster in the Winter Skies, M36

“Once you have tasted flight, you will forever walk the Earth with your eyes turned skyward, for there you have been, and there you will always long to return.” -Leonardo da Vinci

Welcome back to another exciting Messier Monday here on Starts With A Bang! As Comet ISON dives towards the Sun and a nearly perfect full Moon towers overhead, it's easy to forget about those wondrous deep-sky objects that are fixed, but the 110 prominent members of the Messier Catalogue are always on tap for dedicated skywatchers. Although the extended objects -- galaxies and nebulae -- are difficult to view with a bright Moon out, the star clusters, both open clusters and globulars, still make for spectacular viewing.

Image credit: Rolando Ligustri, via Image credit: Rolando Ligustri, via

Today, we're going to highlight one of the dimmer (and thus, often overlooked) open star clusters of the Messier Catalogue, still clearly visible with even a small telescope or binoculars, provided you know where to look: Messier 36. For those of you who are night owls with clear skies, you may have noticed the recent appearance of the famed winter constellation Orion; that will be your guide to finding this week's Messier object.

Image credit: me, using the free software Stellarium, available at Image credit: me, using the free software Stellarium, available at

The Moon is famous among skywatchers for not only being a towering, brilliant source of light, but also for being a terrible source of light pollution. Tonight's practically full Moon means that the night sky's immediate vicinity around it at a total wilderness site is about as polluted as the night sky in a downtown urban area of a large (Seattle-sized) city. But that doesn't mean you can't still see the absolute brightest stars; Orion rises at around 9 PM over the Eastern horizon and even farther above it is the constellation of Auriga, heralded by brilliant Capella, the third brightest star in the entire Northern Hemisphere, behind only Arcturus and Vega.

Image credit: me, using the free software Stellarium, available at Image credit: me, using the free software Stellarium, available at

Auriga makes an oval-like shape, with bright blue Alnath on the narrow end, opposite Capella and Menkalinan. (Alnath is technically in the constellation of Taurus, but it's by less than a single degree; I'm far from the only one who always thinks of it as part of Auriga.) If you draw an imaginary line from Alnath back towards Menkalinan, you'll come to the naked eye star χ Aurigae, which should still be visible even with the full Moon nearby.

And if you navigate from Alnath to χ Aurigae and head just a little bit farther in that same direction, you won't be able to miss a very nice cluster of stars -- Messier 36 -- in either a telescope or binoculars.

Image credit: me, using the free software Stellarium, available at Image credit: me, using the free software Stellarium, available at

This open star cluster is often challenging if you don't know where to look, as it takes up a very small region on the sky (just a fifth of a degree) and is invisible to the naked eye under ideal dark-sky conditions. Nevertheless, it had been known for more than century before Messier catalogued it, noting it as a:

Cluster of stars in Auriga, near the star Phi: with an ordinary telescope... one has pain to distinguish the stars, the cluster contains no nebulosity.

And if you viewed it in an instrument of Messier's power, you might well reach the same conclusion.

Image credit: Bill Longo, via Image credit: Bill Longo, via

It seems like it barely stands out at all against the backdrop of other stars of similar magnitude. But what appears to be a small and unspectacular collection of dim stars from our point of view is actually an incredible sight, if we're willing to take a look inside.

Image credit: Andy E. Rostron of Image credit: Andy E. Rostron of

A glittering array of mostly blue stars that's quite concentrated, Messier 36 has two particularly bright stars located at its center. Although they might not have stood out to Messier, even a 3" (80 mm) telescope is good enough to see that brilliant central pair!

And if you're willing to dive in with a really high-quality telescope, you can find out a whole lot more!

Image credit: © 2013 Smoot; Star Shadows Remote Observatory, via Image credit: © 2013 Smoot; Star Shadows Remote Observatory, via

A quite young cluster with no red giant stars inside, the bluest star found in Messier 36 is of spectral class B2, just barely below the threshold of stars that end their lives in supernovae!

The reason this cluster appears so small and faint is because it's so far away; at a distance of 4,100 light years it's one of the top-10 most distant Messier open clusters, some ten times as far away as the Pleiades. At its current distance, it's 14 light years in diameter, making it almost the same physical size as the Pleiades, and based on the stars we find in there, it's only 25 million years old; our Sun is nearly 200 times older!

Image credit: © 2006 - 2012 by Siegfried Kohlert, of Image credit: © 2006 - 2012 by Siegfried Kohlert, of

At least 60 individual stars have been identified in this cluster, although it's easily conceivable that there are hundreds -- if not as many as a thousand -- in there that are simply hidden from our view thus far. It's no wonder; like most open star clusters, Messier 36 is indeed located right in the galactic plane!

Image credit: © 2011, Andy Strappazzon, via Image credit: © 2011, Andy Strappazzon, via

Still, you might ask yourself whether there was anything interesting to learn in the infrared. Is there dust? Red stars simply invisible to our visible eyes? Something else?

Image credit: Two Micron All-Sky Survey (2MASS). Image credit: Two Micron All-Sky Survey (2MASS).

It looks like -- if you didn't know better -- a shooting, red star is in there, doesn't it?

What's amazing is that, to the best we've been able to tell, there really is something interesting in there!

Image credit: NOAO / AURA / NSF. Image credit: NOAO / AURA / NSF.

What is that thing? If only there were a better image to find out! In the meantime, this is the best I've been able to find!

Image credit: NOAO / AURA / NSF. Image credit: NOAO / AURA / NSF.

It looks like a star whipping through the interstellar medium so quickly it's grown a tail, similar to the well-known star Mira, but until better data comes along, it will have to remain a mystery! With that said, it's a great sight for now and all through the entire winter, even when the Moon is at its brightest! And that will have to wrap up another Messier Monday! Including today’s entry, we’ve explored at the following Messier objects:

Come back next week, where another deep-sky object — and another unique story about the Universe — awaits you here, only on Messier Monday!

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"t looks like a star whipping through the interstellar medium so quickly it’s grown a tail,"

Very comet-like.
Like Mira's tail but also like a comet.

If only there were a better image to find out! In the meantime, this is the best I’ve been able to find!

I presume the images were from different nights and same place thus not a comet or temporary object, right? No dates on the images there that I can see.

Certainly intriguing & would be great to discover its identity and details.

We are looking outward to the Perseus arm, so it is conceivable that this is a galaxy. But my money is on a red giant star in the line of site of a more distant nebula.

It's hard to be sure what that is, but it could be a local M dwarf which is being ejected from the cluster--that would account for its high velocity with respect to the local interstellar medium. And since the ejection would be recent (by cosmological standards), the tail would not have had much time to grow.

By Eric Lund (not verified) on 19 Nov 2013 #permalink

wow. interesting. could it be final stages of 2 stars merging?

By Sinisa Lazarek (not verified) on 19 Nov 2013 #permalink

or a black hole chucking some large chunks and some are ejected on the pole? a wish perhaps :)

By Sinisa Lazarek (not verified) on 19 Nov 2013 #permalink

It's just an exclamation point put there by the universe so the Hubble takes a look and lets us admire its beauty :)

Hey everyone, just wanted to give you a heads-up that you should say what you need to say over the next six hours or so here.

The site is undergoing maintenance / migration tomorrow, and may be down for extended periods of time. As such, I won't be able to post and you likely won't be able to comment until the end of the day Wednesday at the earliest. Sorry for the inconvenience, but hopefully all the loading / slowness issues we've experienced over the past couple of months will be a thing of the past.

See you back here soon; thanks for being such an excellent community!

@ ^ Ethan : Thanks for the warning.

A few more thoughts on our mystery red comet-like object here. (Like some of the other ideas here too.)

1. Could it be a proplyd (protoplanetary disk) that's "evapourating" / being blown away (photodissociation the term maybe?) by nearby hot massive stars - just like some proplyds in the Orion nebula?

Of course we can't really see any bright stars nearby and the tail doesn't seem to be pointing away from any but maybe there's one hidden from us by thick dust there - too thick even for the 2MASS, NOAO / AURA / NSF to reveal? Okay perhaps a bit unlikely.

2. Maybe its a young T-Tauri / FU Orionis type star illuminating a surrounding nebula like Hubble's Variable nebula (NGC 2261) that actually seems reasonably plausible and matching , perhaps making this one of the very last of the stars to form in M36?

3. Or what about a protoplanetary nebula or micro-quasar :

that's seen from an odd angle or suchlike?

What we really need is a spectrum of it! Don't know if anyone here is able to get one of it or more images?

I like some of the other suggestions here such as a background galaxy too. Occurs to me that a distant nebula could also be another possible explanation.

Without more information its going to be really hard to do more than brainstorms such suggestions. More data please!

PS. For comparison of this object with Hubble's Variable nebula (NGC 2261) see :

note the star at the centre is R Monocerotis in case that helps with searching. Plenty of other images for that should be findable too.

A spectrum, a spectrum my (oh I dunno, looks around) .. cup of tea for a spectrum! ;-)

(With apologies to Shakespeare, King Richard III.)

This object has been studied before. I used MAST

to find HST observations, which led me via ADS

to a paper by Magnier et al.

The bottom line is: the object is a young star making the transition from Class 1 to Class 2; that means that the accretion disk is shrinking from "comparable to the central star in mass" to "much less than the central star in mass".

By Michael Richmond (not verified) on 21 Nov 2013 #permalink

As #10 M Richmond noted, the object appears to be a Young Stellar Object known as IRAS 05327+3404 (aka "Holoea", Hawaiian for 'flowing gas') discovered by Magnier et. al. in 1996. Further studies of this object, with a K2 spectrum and possibly associated with the nearby star-forming region Sh2-235, can be found here:…

By Jon Hanford (not verified) on 24 Nov 2013 #permalink