Here is the transcript for my podcast about how to see the constellation Equuleus, the double star Albireo, and Polarissima Borealis
Check out the Astronomy.com's interactive star chart to see an accurate map of your sky. It'll help you locate some of this week's key targets. Astronomy magazine subscribers have access to a slew of cool functions with StarDome PLUS.
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The constellation Equuleus, the spectacular double star Albireo, and Polarissima Borealis are visible in the next few days. We’ll help you find them in this week’s Astronomy magazine podcast.
Hello, I’m Astronomy magazine senior editor Michael Bakich. Each week, I highlight three different night-sky targets for you to see:
One object you can find without optical aid
One object to find with a small telescope, and
One deep-sky object to find with an 8-inch or larger telescope for you avid astronomers.
Be patient, it’s there
The constellation Pegasus represents the mythological winged horse. But did you know that the sky holds a second horse? On Pegasus’ southwest border sits Equuleus — and, yes, the official pronunciation is ek woo oo' le us — the Foal.
By any reasonable standard, this is a weak constellation. It contains none of the 200 brightest stars, has no named star, meteor shower, or Messier object, and it ranks 87th in size out of the 88 constellations that cover the sky. It was, however, one of the original 48 constellations of the Greeks. Ptolemy, who lived from 73 to 151 A.D., mentioned Equuleus in his great work, Almagest.
To see the Foal, or at least the faint stars that form its figure, first find the magnitude 2.4 star Epsilon (ε) Pegasi. We used this star a couple of weeks ago to find the bright globular cluster M15. Just look 7° due west of Epsilon. Don’t expect to see much. Equuleus’ brightest star — Alpha (α) — glows at a disappointing magnitude 3.9. The fainter stars just north and just east of Alpha form the rest of the constellation.
Wow!
To offset presenting a really faint naked-eye object, I urge you to point a small telescope at Albireo (Beta [β] Cygni). Most northern observers consider this the sky’s finest double star.
Astronomers label Albireo’s two components β1 Cygni and β2 Cygni. β1 shines at magnitude 3.4, while β2 is fainter, coming in at magnitude 5.1. But it’s not their magnitudes that make these stars a terrific sight: It’s their colors.
Before I describe the colors of these two stars, let me say that no two human eyes see precisely the same hues. That said, most observers “see” β1 as golden and β2 as sapphire blue. Whether you see gold and blue, blue and white, yellow and green, or any number of other combinations, it all adds up to a strikingly different pair.
Nanook of the north
This week’s deep-sky object is a tough one: spiral galaxy NGC 3172 in Ursa Minor. Because it glows dimly at magnitude 13.6 (and some estimates put it fainter than magnitude 14) you’ll need at least a 10-inch scope and a really dark sky to spot it.
But if you live north of the equator, you do have an advantage. You can search for NGC 3172 any night of the year. That’s because it lies only 1.5° from Polaris (Alpha [α] Ursae Minoris) — the North Star. In fact, it’s the closest NGC object to the North Celestial Pole — only 0.9° from that heavenly marker. Because of its extreme northern position that keeps it above the horizon for just about the whole Northern Hemisphere, astronomers have dubbed NGC 3172 Polarissima Borealis.
Visually, this isn’t the Whirlpool Galaxy (M51). In fact, it’s pretty uninteresting apart from its location. If you spot it, you’ll see a faint oval haze about 0.5' across with a slightly brighter center.
Last week's podcast: Andromeda Galaxy M31, Gamma Andromedae, the Deer Lick Group
Last week's transcript
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