Can you see stars in other galaxies?

[Swithin StCleeve]

It's one of those daft questions that I feel almost embarrassed to ask. But from Earth, can even the biggest telescopes see individual stars in other galaxies?

 

[michael.h.f.wilkinson]

My telescopes only allow me to see exploding stars in other galaxies (supernovae), but Edwin Hubble used analysis of individual Cepheid variables in other galaxies to plot their distance. So, yes, big telescopes readily show stars in (more nearby) galaxies

[geoflewis]

Yes, and it is by using Cepheid variables which are very bright stars, that Edwin Hubble first started to estimate the distance to galaxies. During a supernova explosion it is even possible to see those dying stars using very modest telescopes or even binoculars.

[ollypenrice]

Hubble's famous 'VAR!' star was recorded photographically, though, as were the subsequent observations used to plot its classic Cepheid light curve. At east that's what is suggested here. https://www.nasa.gov/mission_pages/hubble/science/star-v1.html

I don't know, though, how the plates were used to estimate the brightness. A simple measurement of the size on the plate? If anyone knows I'd love to find out.

The article also says that the projected image of M31 from the 100 inch Hooker would have been five feet long at the plate scale in question. Rather an impressive statistic!!

Olly

[Swithin StCleeve]

That's an interesting link.

"The Hubble telescope sees many more and much fainter stars in the field than Edwin Hubble saw, and many of them are some type of variable star," Mutchler says. "Their blinking makes the galaxy seem alive. The stars look like grains of sand, and many of them have never been seen before."

So when it comes to normal stars, (I know there's not such a thing, I mean none- supernovae), we can't resolve individual stars in other galaxies, but the Hubble Space Telescope can.
I didn't realise the importance of these Cepheid variables. They pretty much proved other galaxies exist, didn't they? 

[swamp thing]

35 minutes ago, Swithin StCleeve said:

That's an interesting link.

"The Hubble telescope sees many more and much fainter stars in the field than Edwin Hubble saw, and many of them are some type of variable star," Mutchler says. "Their blinking makes the galaxy seem alive. The stars look like grains of sand, and many of them have never been seen before."

So when it comes to normal stars, (I know there's not such a thing, I mean none- supernovae), we can't resolve individual stars in other galaxies, but the Hubble Space Telescope can.
I didn't realise the importance of these Cepheid variables. They pretty much proved other galaxies exist, didn't they? 

 

I do remember an article in "Astronomy' Magazine (many years back) where some lucky people were able to look through the 200" scope on mount Palomar. The writer of the article described the core of the Andromeda galaxy as looking like a huge globular cluster consisting of millions of stars.  So Yes we can see "normal" stars in other galaxies......just not with our little backyard scopes. 

 

[Swithin StCleeve]

18 minutes ago, swamp thing said:

 

I do remember an article in "Astronomy' Magazine (many years back) where some lucky people were able to look through the 200" scope on mount Palomar. The writer of the article described the core of the Andromeda galaxy as looking like a huge globular cluster consisting of millions of stars.  So Yes we can see "normal" stars in other galaxies......just not with our little backyard scopes. 

 

Riiight. So really, not such a daft question. We can see individual stars in other galaxies through earthly telescopes. But only bloody big ones!

 

[Knight of Clear Skies]

These days, a small telescope/camera combination can pick up a few of the brightest stars from relatively close galaxies. For example, this recent image includes V1 in Andromeda.

[Knight of Clear Skies]

This report suggests it's possible to view some of the stars in the NGC206 star cloud in M31 with a 15" scope.

[swamp thing]

35 minutes ago, Knight of Clear Skies said:

This report suggests it's possible to view some of the stars in the NGC206 star cloud in M31 with a 15" scope.

Excellent stuff, thanks for that might have a butchers myself now  

 

[RobertI]

Hats off to @Swithin StCleeve for being brave enough to ask a question that wasn't so daft after all! I love these kinds of question, I always learn so much.

4 hours ago, Knight of Clear Skies said:

This report suggests it's possible to view some of the stars in the NGC206 star cloud in M31 with a 15" scope.

A fascinating article, I think I will have a go at NGC206 with my little Lodestar live imaging setup (because I know that I won't have a hope of resolving visually with my C8).

It was also interesting to see a sketch which was generated in Photoshop - not something I have come across before, might start another thread on this.....

 

[niallk]

4 hours ago, Knight of Clear Skies said:

This report suggests it's possible to view some of the stars in the NGC206 star cloud in M31 with a 15" scope.

Great! Must try this out - thanks for posting 

[Paul73]

I hate these threads. I've got to go and do a load of reading now.

Started reading the posts hoping for a 'yes' (great start looking), or a 'No' (forget about it). And we end up with a 'No', a 'yes' and a 'sort of no and yes at the same time!!!!

Good thread. Googling 'Cephied Variable' as I type.

Paul

[gorann]

Well, you can at least image Hubble's Cephied star in M31 with a 5" refractor, I proved it in the thread below. So going back to the original question, it should be no problem at all for the biggest scopes to image stars in other galaxies, but looking through an eyepiece (which they probably never do with the biggest scopes) I would guess no. You need a camera.

 

[Horwig]

10 hours ago, ollypenrice said:

Hubble's famous 'VAR!' star was recorded photographically...

Olly

Beaten by Gorann, but this image of Hubble's Cepheid was from an FSQ106 at Olly's place two years ago, proves how much has changed in the years since Hubble:

Huw

 

 

[Alien 13]

I read somewhere that Andromeda and the Milky way might be already touching each other, would it be possible that some rouge stars have already been captured by our system and could be imaged..

Alan

[michael8554]

You measure the distance to nearby Cepheids in the Milky Way and Magellanics by parallax and other methods, and measure their apparent brightness and period of their variability.

There's a relationship between Cepheid absolute brightness and the period of the variability, discovered by a computer at Harvard aka a clever young women in the early 1900's.

So knowing the period and apparent brightness of Hubble's Cepheid you can calculate it's absolute brightness. Then its distance is how far away must it be to have this apparent brightness.

Something like that.......

Michael

[ollypenrice]

9 hours ago, Horwig said:

Beaten by Gorann, but this image of Hubble's Cepheid was from an FSQ106 at Olly's place two years ago, proves how much has changed in the years since Hubble:

Huw

 

 

Aha, nice one Huw! I've never plate solved my own M31 from our Taks in search of Var1.

Olly

[tomato]

On John Taylor’s brilliant website ‘Cloudedout’ he has an image of Hubble’s Cepheid taken with his 6” RC  and an Atik 460. And that’s also a long way from the Hooker 100”!

[LukeSkywatcher]

On 11/9/2017 at 12:17, Swithin StCleeve said:

Riiight. So really, not such a daft question. We can see individual stars in other galaxies through earthly telescopes. But only bloody big ones!

 

Through massive ones. Anything in your back garden will only show the actual galaxy as a a faint fuzzy. Star clusters on the other hand, you can see individual stars in it with pretty much any scope and enough magnification.

P.S.~ here on SGL we have a "mantra" which is:

The only daft/stupid question is the one you DONT ask. 

[Swithin StCleeve]

None astronomers often ask me "what's the furthest you can see with that telescope". I tell them they can see stuff 2.5 million light years away with their naked eye, so really, distance isn't the issue. But seeing as the Andromeda galaxy is our nearest 'star neighbourhood' that isn't in our galaxy, I wondered what kind of scope you'd need to resolve the stars.

Clusters like M13 are next door in comparison. It's something like 22 light years away.

[goodricke1]

2 hours ago, Swithin StCleeve said:

Clusters like M13 are next door in comparison. It's something like 22 light years away.

I wish it were 22 LY away, it would be some sight!

[Shibby]

1 hour ago, goodricke1 said:

I wish it were 22 LY away, it would be some sight!

Yeah it's actually 22,000 LY away!

I had heard of stars being resolved in images of M33, so went looking. I did find this: http://www.capella-observatory.com/ImageHTMLs/Galaxies/M33AndNGC604.htm

Not sure that would really count as an amateur telescope, though! Maybe somebody on SGL could have a crack at NGC 604

[Knight of Clear Skies]

37 minutes ago, Shibby said:

I had heard of stars being resolved in images of M33, so went looking.

The brightest star in M33 is B324. At about mag 15 it's a surprisingly easy target, I managed to pick it up with a DSLR and 200mm lens.

There is a list here of the brightest stars, HII regions and globular clusters visible in M33.

[Swithin StCleeve]

2 hours ago, Shibby said:

Yeah it's actually 22,000 LY away!

 

I knew I should have googled it!