Galactic friends and neighbors

By Phil Plait | July 26, 2011 7:00 am

Every now and again, a Hubble image will kick me back with a wave of nostalgia.

Most Hubble pictures are of specific objects with which I’m not familiar, some galaxy or cluster I’ve never even heard of. Sometimes the great observatory is pointed at a target I do know from my own youth as an amateur astronomer, something I’ve seen myself through my telescope.

And sometimes it’s something with a more personal connection, a galaxy I’ve actually studied, and which reminds me of old friends, figuratively and literally… like this incredible picture of the halo of the Andromeda Galaxy:

[Click to unenchainedmaidenate.] Lovely, isn’t it?

The Andromeda Galaxy is the nearest big spiral like our own. It’s just under 3 million light years away, as big as the Milky Way (even maybe a shade bigger), and bright enough to be seen easily by the naked eye in a dark site. I’ve spent hours looking at it through binoculars and my own telescope. This picture — one of four peering at this gigantic island universe — is looking into the galaxy’s halo, the cloud of stars surrounding the main disk.

You can see right through it, to galaxies beyond. The bigger ones you see are probably hundreds of millions of light years away, but the smaller, red ones? Those are billions of light years away, the light you’re seeing here having left those distant galaxies before the Earth was even born.

When I worked on Hubble, the camera I was hired to help build would frequently look at this region of the sky. It didn’t take dramatic color pictures, but I found some inspiration in them nonetheless. In this image here, a 900 second exposure of NGC 205, a satellite galaxy to Andromeda, the faintest stars are one one-billionth as bright as you can see with your eye. How’s that for perspective?

The funny thing is, as soon as I saw this new Hubble image, I knew right away who took it. Back in my Hubble days, Tom Brown worked down the hall from me, and he was always happy to show me his work, which was looking at the stellar populations of Andromeda. He was always trying to get deeper, more accurately calibrated images. He eventually left Goddard Space Flight Center where we both worked to move to Baltimore and be at the Space Telescope Science Institute. I remember visiting there once and dropping in on him. He had just received new images of Andromeda, at the time the deepest visible light astronomical observations ever made. He gleefully showed me the pictures, even though they had not been publicly released yet, and we marveled together over the sheer number of stars, and one globular cluster in particular (shown below) that was clear and sharp, despite being nearly 30 quintillion kilometers away.

Sure enough, these new images were taken by Tom. I know he’ll get great science out of them, studying the varying lives of stars in Andromeda’s disk, halo, and environs. Other astronomers may use them to look at other objects in Andromeda, or the more distant galaxies peppering the images.

But to me, these images remind me of those days when each new observation was an adventure, something to explore with friends. These images are beautiful and fascinating and increase our knowledge of the Universe, but they are also being investigated by people who do this for the sheer joy of finding things out. I think that in itself is something worth knowing.

Image credit: NASA, ESA and T. M. Brown (STScI)

Related posts:

Happy 20th anniversary, Hubble!
The cold arms and hot hot heart of the fuzzy maiden
Andromeda born out of a massive collision?
A Swift view of Andromeda

CATEGORIZED UNDER: Astronomy, Pretty pictures

Comments (20)

  1. PdlJmpr

    Thank you, Phil! I keep coming back for this, to share your joy and discoveries. You and your friends show your love for the stars by telling what you know about them and you do it well.

  2. I remember my first astronomy professor at the University of Washington was talking about intergalactic distances one day and asked the class what was the farthest object you could see with the naked eye. Coming from a dinky town in Central Washington, I mentioned Andromeda, as it was quite easy to see unaided. The professor snorted and said that was impossible. “MAYBE with binoculars,” he sniffed. Of course, he was from Seattle, where the city lights (not to mention the ubiquitous clouds) obliterated all but the brightest stars. I tried to convince him otherwise, but he never backed down.

    This was also the guy who was so jealous of Carl Sagan, he’d take great delight in presenting his Sagan impression pretty much every other class. Sagan’s Cosmos had just exploded on PBS, while this professor’s pathetic cable access TV show aired at some ungodly hour when about 12 people were watching.

    Good times.

  3. Renee

    I wish there were more context here. It just looks like a patch of sky to me. I can’t tell how big it is, I can’t tell where the Andromeda galaxy is in relation to it. I wish there were a larger image that showed where these images were taken in relationship to the bulk of the galaxy. Even coordinates on the X and Y axes would help.

    It *is* a beautiful picture, though.

  4. I am an astronomy geek but with running a business, working full time and my MBA it’s hard to keep up on all the information and images out there. I’ll keep checking back so I can get my fix! I find kuhnigget’s comment amusing…my astronomy professor at San Francisco State was very upset, and jealous, of the pluckings at Berkeley.
    But I do agree with Renee in that I can’t tell what I’m looking at.
    Great post!

  5. Baric

    The first human spacecraft, called “Dawn”, began their one circling the second largest asteroid in the solar system – Vesta, located in the mysterious zone between Mars and Jupiter.

    Spacecraft poetic name “Dawn” began his one-year travel around the second largest asteroid, named in honor of the Roman goddess of hearth fires and Vesta.

    Around the same time next year, set out toward the biggest, which is also called a dwarf planet – Ceres, who was called so in honor of the Roman goddess of agriculture.

    Officials of the U.S. National Aeronautical and Space Administration (NASA) disclosed that it is the first and largest human spacecraft that will orbit two celestial bodies in a mysterious asteroid belt, between Mars and Jupiter, dotted with an abundance of larger and smaller “cosmic rock”, since the residual sun’s family of shaping time.

    After cross 188 million miles in, almost four years (send out in September 2007), “Dawn” will, circling at an altitude of 16 thousand kilometers, the entire surface of Vesta record year. For this task, among others, particularly equipped with two devices – one that records (detected) gamma rays and neutrons, the second infrared light, which captures the distant landscape.

    See more here:

  6. Messier Tidy Upper

    Great picture. That’s what I call a halo! :-)

    (Even if it looks nothing like the conventional imconographic one. ūüėČ )

    An inset box showing where this picture is in relation to the rest of Messier 31 (a.k.a. the Andromeda Galaxy) would be nice – I agree with (#3) Renee on that.

    ..these images remind me of those days when each new observation was an adventure, something to explore with friends.

    Isn’t that *still* true?

    Though maybe in a somewhat different way now?

    These images are beautiful and fascinating and increase our knowledge of the Universe, but they are also being investigated by people who do this for the sheer joy of finding things out. I think that in itself is something worth knowing.

    Well said and seconded by me. :-)

  7. SkyGazer

    “But to me, these images remind me of those days when each new observation was an adventure, something to explore with friends.”

    Admit it. You want a new and bigger scope.

    It¬īs all about getting the mrs so far she agrees.
    We all have been there.
    Just keep pushing her.
    She¬īll give in.

  8. Worlebird

    @Renee #3: Follow the link to the source of the images, and there is a nice wide field shot with the locations labeled. I had the same question, and I was a little surprised to discover the context.
    Here’s a direct link to the image you want:

  9. SirButcher

    To me, such an images remind me how a little nothing I am :)

    Just imagine: as you are looking to some distant galaxies, where million and millions of star orbing, with much-much more planets: maybe more then the humanity would be ever count, more which we could ever explore; maybe, there was (many million years ago) a tiny-tiny life-form, who looked up to the sky: tried to look throught the unbeliable deep space. And maybe its eye saw the light of our galaxy: where a tiny star, and an even smaller planet… We resides, looking up to the deep space, and trying to imagine, what could be out there…

  10. Renee’s right. We need an inset image to give us context. Otherwise it’s just another awesome deep field… Did I just say that? “Just another awesome”? Wow…

  11. If you want context, there’s a wide-field image of the Andromeda Galaxy here:

    Which shows where this image is located. (It’s the square labelled “D”). It’s in the halo, far out from the galaxy’s disk.

  12. DrFlimmer

    So, this is Andomeda’s backyard. Interesting. Nice flowers in a black tapestry. That’s what I call a garden. ūüėČ

  13. Keith Bowden

    “My Flying Spaghetti Monster… it’s full of stars!”

  14. Haw haw! Anybody else game enough to click on Baric’s link (#5)?

    Hee hee! Murgatroyd! I do hope English is not his first language.

  15. lqd

    So what does a professional astronomer do, Phil? I’ve always assumed they spend lots of time studying Hubble pictures or analyzing images of distant galaxies with large telescopes, but you make it seem like they barely even see spectacular images like this, and never look through a ‘scope.

  16. Steve Wright


    This was posted the other day at Universe today:

    It might help…

  17. Paul

    I just sat and stared. Than I had to email my brother to share.

    But as a non-astronomy geek (but, I suppose, a general geek – at least according to the wife), I have to respectfully disagree with Renee.

    I don’t think it’s important exactly where it is (that would be like seeing a picture of a stunning landscape and asking for the GPS coordinates – does it matter?) Just look at the galaxies and wonder. Then think about all of that in a singularity and wonder some more. And, as far as I’m aware, space is like this in virtually any direction. Pale Blue Dot indeed.

    I just feel humble at my lack of knowledge and understanding.

  18. Sam H

    @14 kuhnigget: Indeed!! ūüėÄ Obvious but still amazing how coherent language is fundamentally based on correct word order and choice – he made me laugh enough I choked a little :)

    And @17 Paul: I agree that keeping an aspect of mystery to the unknown always has its benefits in illuminating the human imagination to all the possibilities, but of course human curiosity is too impatient to just sit with that and let it be. But isn’t that why science exists anyways, so we could even be enjoying this digitally compressed image, existing on a superhighway of endless information encoded into the very essences of magnetism and light itself, on a device made from materials that were extracted from the remains of living creatures with the very same biochemistry as ourselves, all in the comfort of well-heated homes that draw their energy from fuel, made from the crushed, liquified carcasses of those same creatures who last breathed eons before history? :)

  19. miked

    I agree with Renee – some context would have been great

  20. Chip

    In the main picture, those spiral galaxies well beyond Andromeda are just beautiful.


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