When is the best time to observe 15 Canis Majoris?

15 Canis Majoris is best observed from November through January, with peak visibility during December when it transits around midnight in the Northern Hemisphere.

Where is 15 Canis Majoris located in the sky?

15 Canis Majoris lies in the constellation Canis Major at right ascension 06h 54m and declination -20° 13′.

What telescope do I need to see 15 Canis Majoris?

At magnitude 4.8, 15 Canis Majoris is visible to the naked eye from dark skies, easy in any binoculars.

15 Canis Majoris — Star in Canis Major

Magnitude 4.8^m Star Canis Major (CMa) Visible

Star Map + List + Plan

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1Physical Properties

Magnitude 4.83

Range 4.81 - 4.83

Period 4.4 hours

Variable Type Beta Cephei (Pulsating)

Spectral Type B1IV subgiant

Star Color Blue (B-V -0.21)

2Position & Identifiers

RA 06h 53m 32.9s

Dec -20° 13' 27.0"

Constellation Canis Major (CMa)

HR 2571

HIP 33092

HD 50707

SAO 172520

Flamsteed 15 CMa

Variable ID EY CMa

SIMBAD

3How easy to spot?

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Equipment	Bortle 3	Bortle 4	Bortle 5
Naked eye Naked eye	Medium+	Medium	Hard+
50 mm finder 50mm finder	Easy	Easy	Easy
150 mm telescope 150mm scope	Easy	Easy	Easy

Easy Medium Hard Very hard Impossible

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

4Visibility

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Best season Nov – Jan (peak: Dec)

5Survey Image

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6

Size Comparison

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7

Compare Stars

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8

Spectral Classification

9

Hertzsprung-Russell Diagram

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Read: The Hertzsprung-Russell Diagram — Reading Stars Like a Map

10

Stellar Lifecycle

11

Blackbody Spectrum

12

Stellar Absorption Spectrum

Simulated absorption spectrum based on spectral type. Hover over lines to identify elements.

13

Stellar Fusion

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14Stellar Notes

Variable Star

Beta C 4.60 - 4.63B, 0.184557 and 0.19296d, beat per. about 2d.

Group/Cluster

Probable member Collinder 121 (#24); OB group near Omicron CMa.

Radial Velocity

0.184558d.

Alternative Names

Old sources call this Pi1 CMa, HR 2558 Pi2 and HR 2590 Pi3. Superscripts no longer | retained.

Nearby in the Sky

Other targets within a few degrees — pan your scope a little and keep exploring.

Visibility scores assume a 150 mm Newton at Bortle 4.

Open Cluster mag 4.5 1.6° Canis Major

NGC 2296

Hard+

Elliptical galaxy

Galaxy mag 13.0 3.5° Canis Major

29 CMa

Hard+

Eclipsing binary, period 4.4d

Variable Star mag 4.98 7.2° Canis Major

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