The Sky in May

A Selection of Double Stars in Corona Borealis

April 2007 : By Glenn Chaple

It’s time to come out of hibernation! After two months of intense cold weather here in the Northeast, mild temperatures are returning. Celebrate spring with a visit to one of the season’s loveliest constellations, Corona Borealis. The Northern Crown is home to a splendid collection of double stars. Here are ten of the most noteworthy.

Spring Double Stars: The Three Leaps of the Gazelle

March 1997 : By Nan D'Antuono

The Great Bear Ursa Major is high in the north these Spring evenings. Along his southwestern border, shared with the constellations Lynx, Leo Minor, and Leo lie the three distinctive pairs of third magnitude stars known from ancient times by many names, one of the best known of which is the charming name "The Three Leaps of the Gazelle." Three of the six leap stars are wonderful doubles, and there are many more awaiting discovery in Ursa Major.

Some Bright Summer Double Stars

June 2005 : By Glenn Chaple

In this modern era of the huge galaxy-gulping Dobsonian reflector, double stars have become the neglected children of the cosmos. That’s too bad, because few heavenly objects have the visual appeal of double stars.

Some Bright Spring Double Stars

April 2006 : By Glenn Chaple

To most deep sky enthusiasts, spring means “galaxies.” Hundreds of these island universes – many in the Coma-Virgo cluster – are within the reach of backyard scopes. Often forgotten are the beautiful double stars that also inhabit the spring skies. Here are ten of the best:

A Selection of Double Stars in Boötes

July 2006 : By Glenn Chaple

During the warm summer evenings, the constellation Boötes is perched high in the sky after sunset. The Herdsman is a rich hunting ground for double stars.

A Selection of Double Stars in Draco

July 2008 : By Glenn Chaple

A hazy summer evening may prevent you from observing nebulae and galaxies, but it could afford ideal seeing conditions for high power targets like double stars.

A Better Galaxy Guide: Late Spring

May 2009 : By Craig Cortis

Those of you who enjoyed my first installment on this subject will find this second part to be even better. Three constellations are covered on the accompanying list of recommended objects and two—Virgo and Coma Berenices-feature the grandest, richest assortment of galaxies bright enough to be seen in small-to-medium aperture instruments.

Mizar, The First Double Star

May 2009 : By Glenn Chaple

The middle star in the handle of the Big Dipper, Mizar is the easiest double star for the novice to locate. It boasts historical importance as the first double star discovered.

44 Boötis

June 2009 : By Glenn Chaple

44 Boötis, whose 210-year orbit is highly inclined to our line-of-sight, has opened up. Its magnitude 5.3 and 6.2 component stars are separated by 2.2 arc-seconds.

Messier 6 and Messier 7

July 2009 : By Glenn Chaple

The song “Love and Marriage,” contains a line that goes, “you can’t have one without the other.” The words aptly describe the open clusters M6 and M7 in Scorpius. This cosmic “horse and carriage” lies in the southern sky above the Scorpion’s stinger.

Can You Find a Quasar? (You Might be Surprised)

May 2010 : By Craig Cortis

Readers having 8” or larger telescopes might wish to observe a quasar, provided you can follow a detailed finder chart and manage to isolate a 12.8 magnitude object that looks exactly like a star, but actually is not. Rather it’s the brightest known quasar and, at a distance of 2.5 billion light years, will be by far and away the most distant thing in the universe most of you will ever see in your lives.

M40: The “Unknown” Messier Object

May 2010 : By Glenn Chaple

Arguably the oddest member of the Catalog, M40 isn’t a cluster, nebula, or galaxy. It’s a double star! We might well label M40 “Messier’s Mistake.”

It’s Full of Stars!

June 2010 : By Dave Huestis

This month Dave Huestis examines the 5th largest constellation in the sky - Hercules. While there are many mythological stories about this giant, one of the most beautiful objects in the heavens resides within its borders. It's full of stars!

NGC 6207

July 2010 : By Glenn Chaple

Most backyard astronomers are so entranced by the Great Hercules Cluster M13 that they fail to notice a small, faint oval patch of light a half degree to the northeast. This is the 11th magnitude galaxy NGC 6207.

Izar (ε Boötis)

June 2010 : By Glenn Chaple

A larger telescope and magnifying power of 200X will readily split Izar and reveal a striking color contrast between the golden yellow primary and its bluish companion. The Russian astronomer Wilhelm Struve, who conducted a double star survey in the late 1820s and early 1830s, nick-named it “Pulcherrima” (The Most Beautiful).

May Constellations & Folklore

May 2011 : By Francine Jackson

As the sky begins to remind us that a new month is approaching, we are able to see a constellation that is often forgotten, but much more important than we usually let on.

β Scorpii

June 2011 : By Glenn Chaple

This month, we travel southward to the constellation Scorpius and the showpiece double star beta (β) Scorpii, also known as Graffias. Beta Scorpii is an eye-pleasing pair of magnitude 2.6 and 4.5 stars separated by 13.6 arc-seconds. The magnitudes and separation are quite similar to those of the better-know Mizar; indeed, Graffias rivals Mizar in visual splendor.

3C 273: Quasar in Virgo

May 2011 : By Glenn Chaple

“How far can you see with that telescope?” It’s a question I occasionally hear from visitors who peer into my telescope at public star parties. The farthest my telescopes have taken my eye, I tell them, is 2 billion light years - to the quasar 3C 273.

M92: Globular Cluster in Hercules

July 2011 : By Glenn Chaple

Quick question. How many times (to the nearest thousand) have you viewed the great globular cluster M13 with your telescope? Next question. How many times (nearest thousandth) have you visited Hercules’ other great globular cluster M92? I doubt it would be an exaggeration to say that I’ve seen M92 once for every hundred times I’ve viewed M13.

Porrima: Binary Star in Virgo

May 2012 : By Glenn Chaple

Compiling a list of the finest double stars for backyard telescopes is always a work in progress. The list is forever in flux, because many showpiece double stars are binary systems that periodically close to the point where they can’t be resolved by small-aperture telescopes. Such is the case with Porrima (gamma [γ] Virginis).

M97: The Owl Nebula

June 2014 : By Glenn Chaple

Like its neighbor M108, M97 was discovered by Messier’s contemporary Pierre Méchain in 1781. Described as one of the fainter of the Messier objects, M97 can nonetheless be glimpsed with small aperture scopes.

M5: Globular Cluster in Serpens

June 2012 : By Glenn Chaple

Like M13, M5 is one of the few globular clusters that can be resolved with small scopes.

M101: Spiral Galaxy in Ursa Major

April 2013 : By Glenn Chaple

One of the best examples of a star-hop is the one that takes us from Mizar (the middle star in the Handle of the Big Dipper) to the face-on spiral galaxy M101. It’s a fortuitous situation because, were it isolated, M101 might be one of the more difficult Messier objects to locate.

M104: The Sombrero Galaxy

May 2013 : By Glenn Chaple

One of the more noteworthy examples of an edge-on spiral galaxy bisected by a dark dust lane is M104, the Sombrero Galaxy. The nick-name arises from the galaxy’s resemblance to the traditional Mexican headwear, the bright nuclear bulge forming the hat and the spiral arms/dust lane the wide brim.