Starship Asterisk*

by **BDanielMayfield** » Sat Feb 22, 2014 6:30 pm

Ann wrote: I doubt that we can see the red dwarfs that belong to M44 is this picture. Bear in mind that the brightest members of the Beehive cluster are about 70 times brighter in optical light than the Sun. A typical red dwarf may, at best, produce about 7% as much light as the Sun according to wikipedia. However, the brightest known M-type dwarf, AX Microscopii, emits only about 3% as much optical light as the Sun. And bear in mind that Proxima Centauri, the nearest red dwarf of spectral class M5V, produces only one part in 18,000 as much optical light as the Sun!

So, no, I don't think that the red dwarfs of M44 will show up in this picture. But maybe someone disagrees with me?

Ann

I reckon so too Ann, but it would be nice to know enough to know for sure. I do know that, discounting dust, brightness drops as the square of the increase in distance. I wonder what the magnitude limit is for this image? Once that is known, we can determine the absolute mag is for the dimmest stars in this view.

Bruce

by **Ann** » Sat Feb 22, 2014 5:57 pm

Guest wrote:It would be nice to know if the stars which are very 'close' to each other in the photo are members of double or even triple systems.
Interesting also is some of the very faint "close' stars appear reddish, like red dwarf stars. Are they?

I doubt that we can see the red dwarfs that belong to M44 is this picture. Bear in mind that the brightest members of the Beehive cluster are about 70 times brighter in optical light than the Sun. A typical red dwarf may, at best, produce about 7% as much light as the Sun according to wikipedia. However, the brightest known M-type dwarf, AX Microscopii, emits only about 3% as much optical light as the Sun. And bear in mind that Proxima Centauri, the nearest red dwarf of spectral class M5V, produces only one part in 18,000 as much optical light as the Sun!

So, no, I don't think that the red dwarfs of M44 will show up in this picture. But maybe someone disagrees with me?

Ann

by **jsanchezjr** » Sat Feb 22, 2014 5:20 pm

BDanielMayfield wrote:
Guest wrote:It would be nice to know if the stars which are very 'close' to each other in the photo are members of double or even triple systems.
Interesting also is some of the very faint "close' stars appear reddish, like red dwarf stars. Are they?
The majority of stars are in multiple systems, so there would be a large number of multiple systems in today’s APOD. But it's hard to know if stars are actually close, or just appear that way from our point of view.

Exactly. Most of the stars are in multiple system or binary systems. For example, the Alfa Centaury star is realy a binary star system and consist of Alfa Centauri A, Alfa Centauri B and probably a third star(Proxima Centari). Something interesting is that in some of those systems one of them will become a supernova and posibly in some moment will begin to eat some of the mass of the other star finishing in another explotion that throw away the other star. What a relationship ah?...

by **owlice** » Sat Feb 22, 2014 4:37 pm

BDanielMayfield wrote:Therefore, y'all need to zoom in and count, not just the big bright stars, but everything down to all the teeny red specks too

But don't count the galaxies!!

: Screen shot 2014-02-22 at 11.35.19 AM.png (15.18 KiB) Viewed 5844 times

by **BDanielMayfield** » Sat Feb 22, 2014 4:27 pm

Guest wrote:It would be nice to know if the stars which are very 'close' to each other in the photo are members of double or even triple systems.
Interesting also is some of the very faint "close' stars appear reddish, like red dwarf stars. Are they?

The majority of stars are in multiple systems, so there would be a large number of multiple systems in today’s APOD. But it's hard to know if stars are actually close, or just appear that way from our point of view.

by **BDanielMayfield** » Sat Feb 22, 2014 4:18 pm

jsanchezjr wrote:
todd wrote:holds 1,000 stars? where are they? i can see only a dozen or so here
Yes. With others image of the M44 you can see more, not hundred's of them but much more. Here are a more deep information about the quantity from Wikipedia "Altogether, the cluster contains at least 1000 gravitationally bound stars, for a total mass of about 500-600 Solar masses. A recent survey counts 1010 high-probability members, of which 68% are M dwarfs, 30% are Sun-like stars of spectral classes F, G, and K, and about 2% are bright stars of spectral class A. Also present are five giant stars, four of which have spectral class K0 III and the fifth G0 III"

Therefore, y'all need to zoom in and count, not just the big bright stars, but everything down to all the teeny red specks too

That article jsanchezjr quoted also stated that there were none of the most massive, class O stars in this cluster. If there had been, they would have gone Supernova by now, right? But it also stated that the most evolved stars (and therefore the most massive at their start) have now become White Dwarfs. So, this leads me to wonder, class wise, what is the lowest class of the main sequence that will become a Supernova, and what is the highest class that just become White Dwarfs?

Bruce

by **Guest** » Sat Feb 22, 2014 2:01 pm

It would be nice to know if the stars which are very 'close' to each other in the photo are members of double or even triple systems.
Interesting also is some of the very faint "close' stars appear reddish, like red dwarf stars. Are they?

by **jsanchezjr** » Sat Feb 22, 2014 1:24 pm

todd wrote:holds 1,000 stars? where are they? i can see only a dozen or so here

Yes. With others image of the M44 you can see more, not hundred's of them but much more. Here are a more deep information about the quantity from Wikipedia "Altogether, the cluster contains at least 1000 gravitationally bound stars, for a total mass of about 500-600 Solar masses. A recent survey counts 1010 high-probability members, of which 68% are M dwarfs, 30% are Sun-like stars of spectral classes F, G, and K, and about 2% are bright stars of spectral class A. Also present are five giant stars, four of which have spectral class K0 III and the fifth G0 III"

by **starsurfer** » Sat Feb 22, 2014 1:01 pm

I would like to mention that in the description, "equipped" is spelt as "equiped". Also I never expected to see this on APOD, always a surprise.

by **JohnD** » Sat Feb 22, 2014 12:59 pm

Lots of pictures on the 'Net of 'star-forming regions' and young stars, in the gas/dust clouds in which they formed.
The Beehive has no dust at all.

I looked for other pics of star clusters, and found one of the Pleiades, with lots of dust around them, but then learnt that this is not the originating dust cloud, but one that the stars happen to be passing through (Really? And you just happened to be holding a Lead Pipe in the Library, Ms Star?)

So, how quickly after a star/stars ignite will the remains of the original dust/gas cloud be cleared away, completely?
John

by **todd** » Sat Feb 22, 2014 11:58 am

holds 1,000 stars? where are they? i can see only a dozen or so here

by **Beyond** » Sat Feb 22, 2014 11:20 am

In the "suns 4.5 billion year" link, I've discovered that resisting having cents is futile

by **Boomer12k** » Sat Feb 22, 2014 10:41 am

What a wonderfully clear shot. Awesome!

I see more of a slight Christmas Tree shape, personally.

I can hear Messier now....."DARN....Not a comet!!!" In French of course.

Oh, I am sure he found it just as interesting....

:---[===] *

by **Ann** » Sat Feb 22, 2014 7:33 am

This is a fine APOD!

I think of M44 as the cluster where the stars pair up or form triples. Of course they do that in other clusters too, but M44 has no obvious shape and no obvious bright foreground stars to help us recognize it, so to me, this pairing up or "tripling up" of stars helps me recognize the Beehive. Note near top a yellow and a blue star of seemingly equal brightness, with a small white star seemingly intruding itself between them. Note near center another yellow star with two smaller blue-white stars "sitting on top of it" like Mickey Mouse ears. Note, further down and to the right, another yellow star with an itty bitty yellow star on top of itself and two blue-white stars to the left of it. And to the left of them two blue stars form a pair.

In M44, all the bright stars are about equally bright in V light. The red giants are no brighter in V light than the A-type main sequence stars, and the optically brightest star is even a blue A-type star, Epsilon Cancri (near center in this image).

Ann

by **APOD Robot** » Sat Feb 22, 2014 5:17 am

M44: The Beehive Cluster

Explanation: A mere 600 light-years away, M44 is one of the closest star clusters to our solar system. Also known as the Praesepe or the Beehive cluster its stars are young though, about 600 million years old compared to our Sun's 4.5 billion years. Based on similar ages and motion through space, M44 and the even closer Hyades star cluster in Taurus are thought to have been born together in the same large molecular cloud. An open cluster spanning some 15 light-years, M44 holds 1,000 stars or so and covers about 3 full moons (1.5 degrees) on the sky in the constellation Cancer. Visible to the unaided eye, M44 has been recognized since antiquity. Described as a faint cloud or celestial mist long before being included as the 44th entry in Charles Messier's 18th century catalog, the cluster was not resolved into its individual stars until telescopes were available. A popular target for modern, binocular-equiped sky gazers, the cluster's few yellowish tinted, cool, red giants are scattered through the field of its brighter hot blue main sequence stars in this colorful stellar group snapshot.

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Starship Asterisk*

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