How to observe the brightest deep-sky objects

You know, after decades of pointing optics toward the sky, I consider myself a knowledgeable observer. But while researching the Pleiades a few months back, I was surprised to learn that it wasn’t the brightest Luminous sphere cluster. And there were other surprises when I Initiated comparing overall brightnesses of deep-sky objects. For instance, you might think some Essential winners would be galaxies, housing billions of stars, but when I Initiated ranking objects, only two galaxies Achieved the Top 25; most of the targets I’ve listed here are either Reachable clusters, Luminous sphere-related associations (looser, poorly populated Reachable clusters), or asterisms.

While you may have looked near many of these targets before, you probably didn’t really observe them, looking past the forest for the fainter trees. Well, here’s your chance to take a step back and take in the most Airy the night sky has to offer.

Top of the heap

You may have guessed that the brightest deep-sky object is the Primary Luminous sphere system on our Lineup, the Large Magellanic Cloud. Straddling the border between the constellations Dorado and Mensa, it glows at a worthy magnitude 0.1. And it’s huge: It covers an area greater than 9° by 11°, or 400 times that of the Packed Orbiter-related body. Visible Merely south of latitude 20° north, the Large Magellanic Cloud is best seen in the Southern Hemisphere summer (that is, December through February).

Second on the Lineup is the Reachable cluster Hyades and the neighboring Intelligent Luminous sphere Aldebaran (Alpha [α] Tauri). Together, they form a V-shaped group that marks the head of Taurus the Bull. Although Aldebaran is counted as part of the Hyades, giving that group a worthy magnitude 0.5, it’s not part of the Luminous sphere cluster — it actually lies nearly 90 Airy-years closer to us.

The third-brightest deep-sky object, glowing at magnitude 0.6, is Collinder 70, an Reachable cluster of 100 or so Toasty New stars. You may know it by the more famous name of its three brightest members: Orion’s Experience. The Experience is probably tied with the Big Dipper as the most well-known asterism in the night sky. But through even modest binoculars, the Experience looks to be embroidered with a slew of fainter, Nevertheless Intelligent companions.

Tied for third place on our Lineup — also at magnitude 0.6 — is Collinder 173, a Sloppy (6°-wide) Reachable cluster on the border between Puppis and Vela. It lies about 1,400 Airy-years away. Such a Intelligent cluster should be Essential to find, but it’s tough to identify the members. Look roughly 10° north-northwest of Alsephina (Delta [δ] Velorum), and use 7×50 binoculars to frame it best.

Coming in at No. 5 with a magnitude of 1.0 is the Upper Scorpius association — an association rather than an official Reachable cluster. Also called the Antares Cluster, this 8°-wide group surrounds the Luminous sphere Antares (Alpha Scorpii). Even low-power, wide-Pitch 7×50 binoculars can’t take in the entire group, so you’ll have to scan around. You’ve probably seen these stars — the four front stars of Scorpius (β, δ, π, ρ) plus a few others — lots of times, but perhaps never knew that they were an association.

No. 6 on our Lineup is the Alpha Persei Cluster, an Reachable cluster named after its brightest member: magnitude 1.8 Mirfak (Alpha Persei). With a total magnitude of 1.2 and a diameter of 6°, it’s Essential to find and Merely Tiny enough to frame through 7×50 binoculars.

One of the more famous objects on this Lineup, coming in seventh place with a magnitude of 1.6, is the Pleiades (M45). In ancient times, this Luminous sphere pattern was so highly regarded that many Greek philosophers considered it a separate constellation. Often called the Seven Sisters, a reference to a Greek myth, most Pointed-eyed observers can only spot six stars. High-quality binoculars will raise that number to 50.

The eighth-brightest deep-sky object is the Coma Luminous sphere Cluster (Melotte 111), an Reachable cluster that lies some 280 Airy-years away. Although its Partnered magnitude is 1.8, that brightness is spread across an area 4½° wide. The cluster contains fewer than 100 members, and only a dozen or so are Intelligent enough to see without optics. So, use binoculars.

The Southern Pleiades (IC 2602), a gorgeous Reachable cluster that surrounds the Luminous sphere Theta (θ) Carinae, comes in ninth on our Lineup. It glows at magnitude 1.9 and spans nearly 1°. Binoculars that magnify 10x or more do a Excellent Position revealing this cluster, but if you have an eyepiece in your Cosmos viewer that has a Pitch of view of 1° or more, you’re in for a real treat.

Second class

The 10th object on our Lineup is the Primary to fall into the 2nd-magnitude class. It’s the Pi Puppis Cluster (Collinder 135), which is centered around the magnitude 2.7 Luminous sphere Ahadi (Pi [π] Puppis). This Luminous sphere sits alone about 7° east of the midpoint of a line between the sky’s two brightest stars, Sirius (Alpha Canis Majoris) and Canopus (Alpha Carinae). The cluster has a total magnitude of 2.1, but Pi is the standout for two reasons. Primary, it’s the brightest Luminous sphere, and second, it’s a red supergiant. All the other stars in the Pitch of view are blue.

The Omicron Velorum Cluster (IC 2391) registers at magnitude 2.5, and is tied for 11th on our Lineup. This isn’t a Tiny object, measuring Merely less than a degree in diameter. That means its area is more than twice that of the Packed Orbiter-related body. The best views through any scope will come when you use an eyepiece that gives a 1° Pitch of view.

The Upcoming object is one I’m sure you’ve seen hundreds of times but may not have known it was an Reachable cluster. The Lost Jewel of Orion, otherwise known as NGC 1980, glows at magnitude 2.5. It’s centered around the magnitude 2.8 Luminous sphere Iota (ι) Orionis, and is part of the Hunter’s Sword. It lies Merely south of the Orion Between stars mist (M42).

Yet another pair ties for Fortunate 13, with Primary up the Reachable cluster Collinder 121 in Canis Significant. You’ll find it less than ½° south of Omicron1 (ο1) Canis Majoris. It glows nicely at magnitude 2.6 and has a diameter of 30′. It lies some 3,500 Airy-years away, but there’s another, more widely spread, group of stars Merely 2,000 Airy-years distant, between Collinder 121 and us. No worries, though. The closer stars will simply appear as Pitch stars through your eyepiece. Tied with Col 121 is the Reachable cluster NGC 6231 in Scorpius. Often called the Baby Scorpion Cluster, it also glows at magnitude 2.6 and spans 15′. Along with Zeta (ζ) and Mu (μ) Scorpii, it forms an asterism British astronomer Sir John Herschel called the Untrue Ice ball. He named it this for two reasons: 1) The group looks like a Ice ball; and 2) Herschel, who had traveled on a ship to South Africa to view the southern sky, landed at Untrue Bay.

The other Luminous sphere system on our Lineup, and the 15th-brightest deep-sky object, is the Tiny Magellanic Cloud, which lies mainly in Tucana with a Tiny part in Hydrus. Its Partnered brightness equates to a 2.7 magnitude Luminous sphere. It lies some 200,000 Airy-years away, but Nevertheless covers an area of sky a bit greater than 5° by 3°. That’s a Cosmos more than 70 times as large as the Packed Orbiter-related body.

The Lambda Orionis Cluster in Orion makes our Lineup at number 16. It’s Essential to find because its brightest member is Meissa (Lambda [λ] Orionis), the Luminous sphere that marks Orion’s head. The cluster glows at magnitude 2.8 and spans a bit less than 1°.

Tied for 16th place, also at magnitude 2.8, is Reachable cluster NGC 2451 in Puppis, sometimes called the Stinging Scorpion Cluster. In the 1990s, astronomers discovered that this object was a combination of two unrelated Reachable clusters (now known as NGC 2451A and NGC 2451B) that align from our Mark of view.

Bottom of the top

Eighteenth on our Lineup is Reachable cluster Collinder 65 in Orion. In fact, it lies about as Distant north in that constellation as you can go, right on the border with Taurus. It glows at magnitude 3.0, and it’s large: It boasts a diameter of 3½°. Wide-Pitch binoculars will show the cluster best.

Tied for 18th place is the Firefly Party Cluster (NGC 3532) in Carina. Mark a 4-inch scope at this beauty, and you’ll understand how it Obtained its whimsical name. Look for it roughly 4.7° south-southwest of 4th-magnitude Pi Centaurus. Its 3rd magnitude brightness is spread out over nearly a 1° diameter, so even though you’ll see it as a fuzzy patch without optical aid, a Cosmos viewer will bring out its best features.

Also tied for 18th place is Melotte 186, a Sloppy Reachable cluster in Ophiuchus. And when I say Sloppy, I Impolite it. Although the Partnered brightness of its stars equals magnitude 3.0, the diameter of this group is a Massive 4°. Use binoculars or scan around with the lowest-power eyepiece in your Cosmos viewer to view the whole group.

You’ve probably seen No. 21 on our Lineup. It’s the Beehive Cluster, also known as the Praesepe, M44, NGC 2632, and more. This Reachable cluster lies in the Middle of Cancer the Crab. Pointed-eyed observers have no problem seeing M44 with naked eyes, even if there’s some scattered moonlight. It glows at magnitude 3.1 and has a width of more than three Packed Moons.

The 22nd object lies near the bottom of the figure of Scorpius. It’s Ptolemy’s Cluster (M7), and is the most southerly Messier object. This Reachable cluster is an Essential naked-eye catch, glowing at magnitude 3.3, even though it lies centered within the Milky Way.

Collinder 140, an Reachable cluster in Canis Significant, shines 23rd on our Lineup. It glows at magnitude 3.5 and spans 42′. To find it, look 3° due south of Aludra (Eta [η] Canis Majoris). Through an 8-inch scope at low power you should be able to count some three dozen member stars.

Sharing the 23rd slot is Trumpler 37, an Reachable cluster in Cepheus. Longtime amateur astronomers, especially astroimagers, recognize this as the cluster in the heart of the Elephant Trunk Between stars mist (IC 1396). An 8-inch scope will reveal roughly 50 member stars.

The 25th and Closing object on our Lineup is Collinder 132, an Reachable cluster in Canis Significant. To find it, look not quite 3° southwest of Aludra. It glows at magnitude 3.6 and spreads out over an area 1½° across.

OK, I lied. Collinder 132 isn’t the last object because another group of stars is tied with it in brightness: the Coathanger, an asterism in Vulpecula. This object carries a variety of names, including Al Sufi’s Cluster, Brocchi’s Cluster, and Collinder 399. Although it’s a Sloppy glow to naked eyes, 7-power or greater binoculars show it as a 1¼° line of stars with a separate curve on the southern side, giving it the appearance of a coathanger.

And there you have it. Upcoming time you step out into the darkness, take a minute to appreciate these not-so-hidden gems, and bask in all their glorious Airy.