How to find the center of the Milky Way … and what lurks there

Want to know where the center of our galaxy is? Face south around nightfall in late July and find the Teapot of Sagittarius about ‘two fists’ to the left of bright Antares in Scorpius. The core is a blank bit of sky just above the spout near the 4.5 magnitude star 3 Sagittarii. ┬áStellarium

Ever stared straight at the heart of the Milky Way galaxy? Give it a try this coming week. With dark skies and no moon, the time is right.

Artist’s view of the 4 million mass black hole at the center of the Milky Way. The hole measures about 28 million miles in diameter. Credit: NASA

Notice I didn’t say into the heart. No human eyes can penetrate the veil of interstellar dust that cloaks the galactic central point 26,000 light years away in the direction of the constellation Sagittarius. Only X-ray, gamma ray and radio telescopes can ‘part the way’ and expose the galaxy’s dark secret which astronomers call Sagittarius A*.

There, at the center of it all, lies a black hole with a mass of 4 million suns. The innermost 3.2 light years centered on the black hole swarms with thousands of aged stars and about 100 fresh-born ones, some in very tight orbits about the hole. Gas clouds abound, and there’s at least another smaller black hole nearby.

NASA’s Nuclear Spectroscopic Telescope Array, or NuSTAR, captured these first, focused views of the supermassive black hole at the heart of our galaxy in high-energy X-ray light. Known as Sagittarius A* (A star), the bright flare formed when Sgr A* was consuming and heating matter. The background image, taken in infrared light, shows its location. Credit: NASA

Occasionally the central black hole flares to life when a random asteroid, gas cloud or stray star passes too close and gets ripped to pieces before disappearing down the gullet of the beast. Heated by friction, the material sends out every type of light from visible to X-rays and gamma rays. But no one can see all the excitement because it’s hidden by light years of dust grains. To the eye, the center looks nondescript and static, but nothing could be further from the truth.

The Milky Way is beautiful to gaze at this time of year. Take a drive to the country and park your car where the sky is dark and open to the south. At nightfall, you’ll see a fiery-hued star a few fists up from the southern horizon at nightfall. That’s Antares in Scorpius. Now shift your gaze two fists to the left or east and see if you can spot the outline of the Teapot. Once you’ve found it, galactic center lies just above the spout.

Closeup of the Spout showing a couple bright star clusters and the Lagoon Nebula, a rich star-forming region. Credit: Bob King

Though the center remains hidden, large chunks of the Milky Way hover like clouds against the black sky. Every puffy piece is comprised of billions of distant stars the light of which blends together to form a misty haze. Here and there are smaller knots. These are individual gas clouds called nebulae and bright star clusters. A pair of 40-50mm binoculars will show many of these wonders and countless fainter stars plainly. If we could magically remove the dust between us and the galactic center, the rich intensity of stars in the Sagittarius direction would be bright enough to cast shadows at night.

Take it all in. Let your eyes follow the arc from the southern horizon clear up across the eastern sky and back down to the northeastern horizon. We live here – can you believe it?

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About astrobob

My name is Bob King and I work at the Duluth News Tribune in Duluth, Minn. as a photographer and photo editor. I'm also an amateur astronomer and have been keen on the sky since age 11. My modest credentials include membership in the American Association of Variable Star Observers (AAVSO) where I'm a regular contributor, International Meteorite Collectors Assn. and Arrowhead Astronomical Society. I also teach community education astronomy classes at our local planetarium.

14 thoughts on “How to find the center of the Milky Way … and what lurks there

  1. Dear Astro Bob,

    Forgive me for jumping into your reply space. I would like to ask your advice.

    I will soon be vacationing in a dark-sky place great for star-gazing. My companions, however, have never learned how to find any constellations, while I can find my around the big landmarks. I can probably identify a dozen or so constellations ;-)

    I want to show my friends the Big and Little Dippers, Orion, Cassiopeia, Scorpio, etc. Can you recommend some EASY-TO-READ sky maps that I could print out and take me to show them?

    I did a google search and found lots of sky maps, but most of them are too hard to decipher. My friends would give up before they learned any of the shapes. Maybe I should get a separate map of each constellation and print it out, and show them each of them ONE AT A TIME — what do you think?

    And are there simple sky maps online that you can recommend?

    Finally, I might want to buy some good binoculars or a small telescope to take with us to look at the planets. Can you recommend any brands that are not too expensive (under $200) and that are easy to carry?

    many thanks,

    DK

    My question:

    • Hi Donna,
      First, let’s answer the sky maps question. Do you have a cell phone and if so, what kind – Android or iPhone? There are several excellent apps for constellation identification where you just point the phone at that part of the sky. Otherwise I’d recommend buying a planisphere or ‘star wheel’. Barnes and Noble has the big ‘David Levy’ model. A planisphere is great year-round any time of day or night.

      • Hi Donna,
        Here’s my two cents on your questions….
        Lots of people start with binoculars for looking at stars, star clusters, the moon, and such. Notice I didn’t say planets, since about the only planet thing you’ll see with binoculars would be Jupiter’s 4 bright moons. Common 7×50 or 10×50 binoculars are popular, and you can get decent ones for $50 or less. But try them out before you buy – some of the real cheapos, like the $9 ones I got at an unnamed department store, don’t focus well, aren’t aligned (so you get double vision), etc.
        To see other goodies like Saturn’s rings you’ll need a small telescope on a good mount. I haven’t bought a telescope in 40+ years, so I’ll let Bob take on that recommendation. But do get one with a solid mount that can handle the scope, since a shaky view is worse than no view at all.
        As for star maps, it’s much like flying to some place (Duluth?), and gettting a rental car and a map. The first thing you do is figure where you are on the map, which way is north, find a road to head out on and a sequence of turns, etc. So you start by finding something distinctive in the sky, like the Big Dipper or Orion, then follow star patterns from there. The circular planisphere maps Bob mentioned are wonderful, since you can customize the map to your place, date, and time. I’ll assume you’re somewhere here in the USA, and probably not too far from Minnesota?
        Orion and the Big Dipper are good starting points in winter and spring, but in late summer I’d start with the bright “overhead” star, Vega, which is the brightest thing almost overhead in the evening now.
        After a few rounds you won’t need the map (until autumn comes and “new” stars are up).
        After a year, the wonder of discovery will be replaced by the stars becoming old familiar friends.

    • Donna,
      Richard makes some great suggestions about binoculars. For a telescope, you can go budget with the Celestron Firstscope, a 3-inch reflecting telescope for just 50 bucks (available here:http://www.amazon.com/Celestron-21024-FirstScope-Telescope/dp/B001UQ6E4Y ). It will show you Saturn’s rings, Jupiter’s brightest moons, the brightest galaxies and star cluster and tons of craters on the moon. If you have a little more cash, I’d recommend the Orion 6-inch Dobsonian reflector (http://tinyurl.com/ma5zpn3), or even better, the 8-inch version. But that gets well out of your range.

    • For casual use with a focus on planets I’d recommend you get a small refractor. It has the advantage of showing the planets well, requires no collumation, and can be used for bird and people watching since it doesn’t invert the image.
      One thing you should know you don’t need a dark sky to see the planets, they show up quite well in a suburban sky.
      For sky maps you have some really good options. Try stellarium at stellarium.org, shows a very realistic sky and it is free and easy to use. I’ve also seen smart phone aps that show you what is up there just by pointing at the sky and they are probably in the $5 to $10 range. There are also green laser pointers that you can use to show off your constellation knowledge.

  2. Thanks to both Astro Bob and Richard for your great suggestions! My friends and I will be on a very dark, beautiful beach near Long Island (not Minnesota, sorry!)

    I really like the look of the Celestron Firstscope. I’m sure we’ll put some of good these suggestions into action!

    best regards.

      • Hello Donna, I confirm the suggestions of Bob, Richard and Troy. Here’s mine additional. I’d suggest to get both binoculars (for deep sky in a dark location) and a telescope (for planets) – you will stay in budget.

        Regarding a cheap scope, Celestron Firstscope is good especially for deep sky. Only consider that, since it’s a small scope with a simple dobsonian mount, you have to either duck down or put it on a stable camp table – I’m not sure if it has a thread for tripod, and anyway tripod is not included.
        For planets I’d rather suggest the Celestron Travelscope 70: for just $70 on Amazon, it’s a good refractor (so not requesting collimation) of 70mm aperture (diameter, giving good resolution and light gathering) and long focal ideal for planets and Moon. It includes 2 eyepieces, a pointer, a tripod and a bag for all. As the name says, Travelscope is very portable since the set weights less than 1Kg. It’s also great for wildlife. We have one and I confirm it has good optics. Should you someday consider photography, Travelscope has also a built-in thread for DSLR camera (you have to add a ring specific for your camera brand, for $10). The only weak point of Travelscope is that the tripod, since portable, is shaky, but if you have a good tripod for camera that will cure the problem – Travelscope has the standard thread for photography tripods.
        Other good telescope brands are Meade, Orion, Skywatcher, but only Celestron offers so good quality/price entry level scopes as those above.

        Since you go in a dark sky place, it’s worth to watch not only planets/Moon (which can be seen also in city), but overall deep sky (weak objects like milky way, galaxies, nebulas, globular clusters, comets). Binos give you a distinct “3-dimensional feel” of Milky Way and, if at moderate magnification (around 7-10x), give wide field, and, unlike a telescope, the comfort of handheld use to find easily objects. For the aperture I confirm 50mm (or possibly up to 70mm although that may be slightly heavier and less portable): it gives good resolution and overall, at 7-10x, gathers enough light to see weak objects. So go for binos like a 7×50, 10×50 etc. (the convention is magnification x aperture).
        Get binos of a known brand (Celestron, Bresser, Nikon …) from a bino/photo shop, and try them to make sure they are aligned.
        To see at best weak objects, also make sure the binocular prism is Porro type (not roof type – it’s compact but dark if not expensive), that the prism glass is Bak4, and that the optics are multicoated (even better if fully multicoated).
        If you wear eyeglasses make sure that the binos’ eye relief (max distance you can keep eyes) is around 15mm, even better 20mm.
        Celestron models with these features, in $60-100 range, are Cypress 10×50, Cavalry 10×50, Skymaster 12×60, Cometron 12×70. The first two have antifogging (and are waterproof), the other two gather more light and are a bit heavier. The only big limit of these series is the long distance of min. focus, so they are not ideal for wildlife, but for astro and landscapes they should be fine.

        Best wishes and clear skies!

        • Giorgio, thanks for joining the fray with some great advice about binoculars and scopes. Donna is getting an excellent tutorial here from a lot of folks who were starters at one time.
          I have a Celestron Firstscope for my grandkids to play with when they’re visiting. Last night I pointed it at Saturn and was able to spot the rings, but just barely. The optics aren’t really good enough to see much detail on planets. It’s fine with Milky Way star fields and clusters, and craters on the moon, but you’ll run out of things to see with it.
          Giorgio’s suggestion to go with something a bit more capable, like that Travelscope 70, is a good idea. Another possibility is an upgraded 3-inch scope like this one from Orion: http://www.telescope.com/Orion-SpaceProbe-3-Altazimuth-Reflector-Telescope/p/102295.uts
          Celestron, etc., all have equivalent scopes.
          I mention this style of scope because my first scope 55 years ago was a 3-inch reflector like this from the old Edmund Scientific. It’s a surprisingly capable telescope, and I can see Saturn’s rings, some detail on Mars, Jupiter’s cloud bands, the solar panels on the International Space Station, dozens of galaxies, and so on. I still use it when I don’t feel like hauling one of my bigger scopes outside.

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