When is the best time to observe Caldwell 64?

Caldwell 64 is best observed from December through February, with peak visibility during January when it transits around midnight in the Northern Hemisphere.

Where is Caldwell 64 located in the sky?

Caldwell 64 lies in the constellation Canis Major at right ascension 07h 19m and declination -24° 57′.

What telescope do I need to see Caldwell 64?

At magnitude 4.1, Caldwell 64 is visible to the naked eye from dark skies, easy in any binoculars.

Caldwell 64 — Open Cluster in Canis Major

NGC 2362

Open Cluster Excellent (71/100)

Magnitude 4.1^m OpenCluster Canis Major Visible

Credit: Chuck Ayoub. License: CC0. (Wikimedia Commons)

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About C64

Description

NGC 2362 is a compact, young open cluster in Canis Major, about 4,800 light-years away. It is dominated by the brilliant magnitude 4.4 blue supergiant Tau Canis Majoris at its center, surrounded by about 60 fainter members within 8 arcminutes.

Observing Tips

A striking sight in small telescopes, with the dazzling Tau CMa surrounded by a spray of fainter stars. Best at 60-100x. The cluster is easy to find as Tau CMa is visible to the naked eye. Best in winter evenings.

History

Discovered by Giovanni Battista Hodierna before 1654. The cluster is only about 5 million years old, making it one of the youngest open clusters known.

Fun Facts

Tau Canis Majoris, the cluster's brightest star, is actually a multiple star system with at least 5 components. The primary is an O-type supergiant about 50,000 times more luminous than the Sun and will likely explode as a supernova.

Observe

1Properties

Magnitude 4.1

Angular Size 7.2′

Distance 5,100 ly

Description

Open Cluster [Distance: 5100 ly]

Position & Identifiers

RA 07h 18m 41.5s

Dec -24° 57' 14.4"

Constellation Canis Major

Catalog C64

Also known as NGC 2362

Physical size

9.2 light-years across — about 2.1× the Sun-to-Alpha-Centauri distance

2How easy to spot?

Telescope	Bortle 3	Bortle 4	Bortle 5
80 mm refractor 80mm refr.	Easy	Easy	Easy
150 mm Newton 150mm Newt.	Easy	Easy	Easy
Celestron C8 (203 mm SCT) C8 203mm	Easy	Easy	Easy

Easy Medium Hard Very hard Impossible

Bortle 3 = rural · 4 = outer suburbs · 5 = suburbs

Easy on Seestar S50

At 150mm under B5 skies you should resolve about 48 of 144 members.

3Visibility

Set a location in User Settings to see visibility data.

Best season Dec – Feb (peak: Jan)

4 Eyepiece View

Telescope Eyepiece

125x TFOV: 0.4° Lim. mag: 13.6

C64 · 7.2′ diameter

5 Best Magnification

6Where this cluster sits in time

Open clusters span more than four orders of magnitude in age — from newborn OB associations to ancient, metal-rich survivors.

7 Colour-Magnitude Diagram

A cluster's colour-magnitude diagram reveals its age: the bluer the turn-off point where the main sequence bends into red giants, the younger the cluster.

Loading member data…

Each point is a Gaia-DR3 member. Colour encodes spectral type; size reflects membership probability.