New- Star Chart For Cayman

A new feature as of June 2015 has been added - look at the bottom of this web page and there is a new Star Chart exclusively for Grand Cayman

Pedro Castle,April 18th, 7.00 p.m. 2010

Canis Minor, as shown above on the sky chart, is a small constellation which was included in the 2nd century astronomer Ptolemy's 48 constellations, and is still included among the 88 modern constellations. Its name is Latin for "smaller dog" in contrast to Canis Major, the larger dog, and it is commonly represented as one of the dogs following the constellation of Orion the hunter

Canis Minor contains only two bright stars, Procyon, which means "before the dog" in Greek, as it rises an hour before the 'Dog Star', Sirius, of Canis Major, and Gomeisa.

Procyon is the brighter of the two. To the naked eye, it appears to be a single star, the eighth brightest in the night sky with a visual apparent magnitude of 0.34. It is actually a binary star system, consisting of a white main sequence star, named Procyon A, and a faint white dwarf companion of spectral type DA, named Procyon B. The reason for its brightness is not its intrinsic luminosity but its closeness to the Sun; at a distance of 3.5 pc or 11.41 light years, Procyon is one of our near neighbours.

Procyon forms one of the three vertices of the Winter Triangle, along with Sirius and Betelgeuse.

Procyon A is a white star of spectral type F5; it is 1.4 times the mass, twice the diameter, and 7.5 times more luminous than the Sun. It is bright for its spectral class, suggesting that it is a subgiant that has completely fused its core hydrogen into helium, and begun to expand as "burning" moves outside the core. As it continues to expand, the star will eventually swell to about 80 to 150 times its current diameter and become a red or orange color. This will probably happen within 10 to 100 million years. It is expected that the Sun will also go through this process when hydrogen fusion ceases at its core.

The chart also shows the four planets visible. Mercury might be a little hard to see on Sunday, but it has been visible for the last two weeks.

This is a list of the 20 brightest stars as seen from the Earth (not including the Sun). The stars are numbered from 1 to 20 in sequence.

Common
Name

Constellation

Apparent
Magnitude

Spectral
Type

Luminosity
(Sun = 1)

Distance
(Light Years)

Radial
Velocity
(km / sec)

1

Sirius

Canis Major

-1.46

A1

26

8.7

-8

2

Canopus

Carina

-0.72

F0

15,000

310

+21

3

Alpha
Centauri

Centaurus

-0.04

G2

1.7

4.3

-22

4

Arcturus

Bo├Âtis

0.00

K2

115

36

-5

5

Vega

Lyra

0.03

A0

52

25

-14

6

Capella

Auriga

0.08

G8 F0

90 70

43

+30

7

Rigel

Orion

0.12

B8

60,000

910

+21

8

Procyon

Canis Minor

0.38

F5

7

11.4

-3

9

Achernar

Eridanus

0.46

B5

400

85

+19

10

Betelgeux

Orion

0.0 - 0.9

M2

105,000 v

640

+21

11

Agena

Centaurus

0.61

B1

10,000

460

-11

12

Altair

Aquila

0.77

A7

10

16.6

-26

13

Acrux

Crux Australis

0.83

B1

3,200

360

-11

14

Aldebaran

Taurus

0.85

K5

120

68

+54

15

Antares

Scorpius

0.96

M1

7,500

330

-3

16

Spica

Virgo

0.98

B1

2,100

260

+1

17

Pollux

Gemini

1.14

K0

60

36

+3

18

Fomalhaut

Piscis Australis

1.16

A3

13

22

+7

19

Deneb

Cygnus

1.25

A2

70,000

1,800

-5

20

Becrux

Crux Australis

1.25

B0

8,200

425

+20