Messier Monday: The Phantom Galaxy at the Beginning-of-the-Marathon, M74

Posted by Ethan on March 11, 2013
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Image credit: © Barry Etter, Mocksville, NC.
Image credit: © Barry Etter, Mocksville, NC.

“When you run the marathon, you run against the distance, not against the other runners and not against the time.” -Haile Gebrselassie

Welcome to a very special Messier Monday, which just happens to be the twenty-first consecutive week we’ve taken a look at one of the 110 fixed, deep-sky objects that Messier and his collaborators catalogued to avoid confusion with comets.

Image credit: Tenho Tuomi, of his completed Messier Marathon.

Image credit: Tenho Tuomi, of his completed Messier Marathon.

Today’s Messier Monday is very special, because today is the new Moon closest to the vernal equinox. Each year, on (or very close to) the vernal equinox — March 21st (to mitigate my Northern-Hemisphere-bias) — marks your best chance, if you’re atmospherically lucky and at an ideal location, to see all 110 Messier objects in a single night: the Messier Marathon! If, that is, you can tear yourself away from hunting Comet Pan-STARRS in the early evening.

Image credit: Phil Hart of http://www.philhart.com/.

Image credit: Phil Hart of http://www.philhart.com/.

While there are many different (latitude-dependent) guides out there, today I’d like to highlight the first object to set during a marathon attempt from my latitude: the grand design spiral galaxy, Messier 74. Here’s how to find it after sunset tonight.

Image credit: Me, using the free software Stellarium, http://stellarium.org/.

Image credit: Me, using the free software Stellarium, http://stellarium.org/.

It was just a couple of weeks ago that we became familiar with the bright stars Hamal and Sheratan in the constellation of Aries; just after sunset they’ll be visible above the horizon in the West. If you follow the imaginary line that connects those two stars down towards the horizon just a few degrees, you’ll run into another naked-eye star, η Piscium.

And if you can fix your telescope (or outstanding binoculars) on η Piscium, about 1.5° back towards Sheratan you’ll find one of the most challenging Messier objects to observe: M74.

Image credit: me, using the free software Stellarium.

Image credit: me, using the free software Stellarium.

Messier 74 is an incredible challenge for most observers at this time of year, for two reasons:

  1. It’s one of the dimmest objects in the entire catalogue; only one object — the Pinwheel Galaxy — has a lower surface brightness as viewed from Earth, and
  2. It’s very close to the Sun in the sky, so by time it gets dark enough to see this galaxy, it will have almost set!

But if you can get there before it goes away for the spring and summer, this is really one of the most spectacular face-on spirals the night sky has to offer.

Image credit: ROSA observatories, via http://www.cxielo.ch/gallery/f/m74.

Image credit: ROSA observatories, via http://www.cxielo.ch/gallery/f/m74.

Only around 10% of spiral galaxies are classified as grand design spirals, with two large, sweeping arms that extend around the galaxy for quite some distance, and M74 is one of the best examples.

Image credit: Simon Dye (Cardiff University), via http://www.ing.iac.es/PR/science/m74_high.html.

Image credit: Simon Dye (Cardiff), via http://www.ing.iac.es/PR/science/m74_high.html.

At about 30 million light-years away, Messier 74 has about 100 billion stars, making it somewhat smaller than the Milky Way. Although, unlike the Milky Way, it’s by far the largest galaxy in its very small group; the M74 group is one of the few nearby galactic groups that is dwarfed by our own, nondescript local group.

It’s a beautiful sight that you’ll want to observe at low magnification no matter how large your telescope is. Although it will only look like a faint fuzzball through moderate scopes, long exposures + image stacking make this an outstanding target for astrophotography.

Image credit: © 2006 - 2012 by Siegfried Kohlert.

Image credit: © 2006 – 2012 by Siegfried Kohlert.

It also has quite an eerie nickname: The Phantom Galaxy.

Image credit: NASA, ESA, Digitized Sky Survey 2 / Davide De Martin (ESA/Hubble).

Image credit: NASA, ESA, Digitized Sky Survey 2 / Davide De Martin (ESA/Hubble).

Shown above as imaged by the ground-based Digitized Sky Survey, this image is actually reduced from an extraordinary resolution, and the full-size image zoomed in on the Phantom shows exactly how spectacular it is.

Image credit: NASA, ESA, Digitized Sky Survey 2 / Davide De Martin (ESA/Hubble).

Image credit: NASA, ESA, Digitized Sky Survey 2 / Davide De Martin (ESA/Hubble).

But why stop with visible light images? The Spitzer Space Telescope took a composite image of this galaxy in the infrared, and revealed dusty arms full of cool, neutral gas, lending solid observational support to the density-wave theory of spiral-arm structure in spiral galaxies.

Image credit: Médéric Boquien, NASA/JPL-Caltech, Spitzer Space Telescope.

Image credit: Médéric Boquien, NASA/JPL-Caltech, Spitzer Space Telescope.

Ultraviolet light, provided below by GALEX, instead highlights the hottest, newly formed stars in the galaxy, as well as the most energetic ionized regions.

Image credit: GALEX / NASA / JPL-Caltech.

Image credit: GALEX / NASA / JPL-Caltech.

But as always, the best image of Messier 74 comes from Hubble, which really highlights the star-forming regions (in red), the hottest young stars (in blue), and the phenomenally coherent spiral arm structures from the interstellar dust.

Image credit: NASA, ESA, and the Hubble Heritage (STScI/AURA)-ESA/Hubble Collaboration; Acknowledgment: R. Chandar (U. Toledo) and J. Miller (U. Michigan).

Image credit: NASA, ESA, and the Hubble Heritage (STScI/AURA)-ESA/Hubble Collaboration; Acknowledgment: R. Chandar (U. Toledo) and J. Miller (U. Michigan).

I don’t know if any of you are planning to run the Messier Marathon, but you only have until maybe 9 PM to get a glimpse of Messier 74 before she sets if you do. All this week is the best time to try, and if you do, SEDS is happy to certify you!

Image credit: SEDS.

Image credit: SEDS.

I can’t claim credit for this, as I haven’t done it (yet), but perhaps someday I’ll be able to wear that badge with pride!

Until then, I hope you enjoyed another Messier Monday, and don’t forget to check back at all our previous Messier Mondays. Including today, we’ve covered the following:

See you next week for another spectacular deep sky object, where I’ll show you the most difficult Messier Marathon object in the pre-dawn skies!

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Comments

  1. #1 Harold
    Netherlands
    March 12, 2013

    I never heard of the Density Wave Theory. Maybe you could do a pop sci article on that as the wikipedia entry is a bit confusing and it sounds interesting.

  2. #2 Wow
    March 12, 2013

    A suggestion about the images. I think it would be good to give an indication of the aperture, f-ratio and integrated total exposure of the pictures if done from a terrestrial site for the objects.

    It helps give the idea of how much effort there is in astrophotography (even if that effort is not swearing at the cat for rubbing against the tripod and ruining the shot..!) and gives an idea how much less you can expect to see by eye or short (~few minutes) DSLR exposure.

  3. #3 Wow
    March 12, 2013

    I’ve done about half. From the UK, most are very poor objects so if anyone dares say I’m cheating when I’m using a GOTO Scope, then we can swap observing sites and see how YOU like it!!!

    Grrr!

  4. #4 Artor
    March 12, 2013

    I’ve long wondered about spiral galaxies, and why they don’t wind up. The Density Wave explains that pretty well. I’m still wondering though, what forces form a barred spiral? I don’t understand how the bar holds it’s shape. Can you elucidate that for us Ethan? Please?

  5. #5 Wow
    March 12, 2013

    New stars form where the dust is densest: the dust collapses.

    The density wave, not being a material thing that moves in orbit, moves at a different speed and (for example) moves round the galaxy quicker and new rich areas of potential star formation move “ahead” of the stars just formed.

    Bright stars don’t last long, so they die out quickly as they orbit the galactic centre and they appear to give the “front edge” of the “arm” a much brighter appearance.

    Dim stars last a long time and therefore the “back edge” of the “arm” is dimmer.

    The arm only appears to be an arm because the bright stars in it were only recently “visited” by the densest part of the density wave and died quickly.

  6. #6 Sinisa Lazarek
    March 13, 2013

    @ Wow
    “I think it would be good to give an indication of the aperture, f-ratio and integrated total exposure of the pictures if done from a terrestrial site for the objects.”

    I hear you and also wish that was the case, but you know in many cases it’s impossible. Not that many great astrophoto’s carry that info, author’s in many cases don’t list them. And when they have it listed, many times the equipment isn’t. You go and try to replicate the same settings with your camera only to find out they either used CCD’s that costs as much as a decent car, or lenses that cost twice that much :D

    I’m still trying to squeeze as much as I can from my old canon and no tracking. Image stacking helps a lot. But motorized tracker is my next big investment. DSLR with a good 300mm lens and traking can capture simply amazing images of sky, provided you have patience.

  7. #7 Wow
    March 13, 2013

    There are a lot of photos of most of these objects, so picking one that DOES give that should me moderately easy.

    But that’s me telling someone else to do work, so I won’t be offended if Ethan tells me to eff off…!

    (A mono CCD will give you about 2 f-stops better resolution than a GOOD DSLR, and often less than 1 f-stop comparing a colour CCD vs DSLR)

    Since digital is linear (so the old problem of reciprocal failure from emulsion prints is gone), you can just take four shots and stack.

    But it’s more about giving a hint to the potential amateur astronomer about how much they’ll see with their eye.

    PS if you’re not tracking, then you can manage 700/focal length second exposures without tracking and have point-like stars etc. With a 350mm short achromat in prime focus and a APC sensor, that’s 1.5 seconds. With your 300mm that’s a little less than 2 seconds.

    Look at making a Haig mount for your camera.

    Alternatively, if you already have a scope, piggyback and use the telescope to track by hand (you’d want 80x or better magnification to be able to keep it fairly streak-free).

  8. #8 Ethan
    March 13, 2013

    Sinisa and Wow,

    In this post, Siggi Kohlert’s (e.g., http://www.astroimages.de/en/gallery/M60.html) astrophotos have some additional info, as do Barry Etter’s (e.g., http://barryetter.zenfolio.com/). In others, Fred Espenak’s, Twin City Amateur Astronomers, Lee Kelvin and Grant Miller, and many others have camera/equipment info.

    Before we migrated platforms, I was able to include links in image captions; sadly that’s no longer the case.

  9. #9 Sinisa Lazarek
    March 13, 2013

    Just did a quick price check on equipment mr Siggi used for his image of M60. This is what I found

    Scope: GSO 200/800mm Newton – 600$
    TeleVue Paracorr Coma Corrector – 400$
    Camera: Canon 40Da – 850$
    Mount: Modified Eq-6 (700$+) (with Boxdörfer MTS-3 SDI) (450$)
    Guiding: 80/900mm Refractor (150$) with ALccd5 (350$) and Guidemaster

    … so.. all in all about 3500$, maybe a bit more, in gear and almost 2 hours of exposure time. It’s a tough hobby :D

  10. #10 Sinisa Lazarek
    March 13, 2013

    This was my first attempt at Orion with just a camera, tripod and experimenting.

    http://img189.imageshack.us/img189/2739/orion11of1.jpg

    75mm, 3 sec exposure, about 120 stacked images. No darks and bias frames. As a result, there’s a lot of noise. But am pretty pleased with myself for first try ;)

  11. #11 CB
    March 13, 2013

    You should be pleased! That’s a nice shot, even showing some color in M42 and M43. I only wish Betelgeuse was in frame.

  12. #12 Wow
    March 13, 2013

    Good shot. You may want to get a few shorter shots as well and use some HDR tricks to stop bloom on the brighter stars.

  13. #13 Sinisa Lazarek
    March 13, 2013

    Thanks guys :) Waiting for some clear nights to try again. Was hoping to get a shot of the comet these next days, but clouds every night.

  14. #14 Wow
    March 13, 2013

    At the moment, the comet isn’t up until 3:30 am and not usefully up until well past 4am, in the UK.

    I’ll have to wait until summer is nearly over.

  15. #15 Julian
    March 13, 2013

    PanSTARRS should be called PanSUCKKS.