Orbital Motion

Sirius A and Sirius B

Sirius A Sirius A

Center of mass

Orbital Motion Sirius A and Sirius B

Sirius A Sirius A

Center of mass

Orbital plane (looking perpendicular to the orbital plane along the red arrow)

Orbital plane (looking at an angle)

Orbital Motion Sirius A and Sirius B

Sirius A Sirius A

Center of mass

0 31 62 93 124

arc-seconds

Plane of the Sky

Sirius A on the sky

Sirius A and B in space

1850

0 31 62 93 124

arc-seconds

0

+6

-6

arc-

seco

nd

s

1855

0 31 62 93 124

arc-seconds

0

+6

-6

arc-

seco

nd

s

1860

0 31 62 93 124

arc-seconds

0

+6

-6

arc-

seco

nd

s

1865

0 31 62 93 124

arc-seconds

0

+6

-6

arc-

seco

nd

s

1870

0 31 62 93 124

arc-seconds

0

+6

-6

arc-

seco

nd

s

1875

0 31 62 93 124

arc-seconds

0

+6

-6

arc-

seco

nd

s

The "center of mass" will remain fixed in the following slides.

Watch the orbits carefully.

1880

0 31 62 93 124

arc-seconds

0

+6

-6

arc-

seco

nd

s

1885

0 31 62 93 124

arc-seconds

0

+6

-6

arc-

seco

nd

s

1890

0 31 62 93 124

arc-seconds

0

+6

-6

arc-

seco

nd

s

1895

0 31 62 93 124

arc-seconds

0

+6

-6

arc-

seco

nd

s

1900

0 31 62 93 124

arc-seconds

0

+6

-6

arc-

seco

nd

s

1905

0 31 62 93 124

arc-seconds

0

+6

-6

arc-

seco

nd

s

1910

0 31 62 93 124

arc-seconds

0

+6

-6

arc-

seco

nd

s

1915

0 31 62 93 124

arc-seconds

0

+6

-6

arc-

seco

nd

s

1920

0 31 62 93 124

arc-seconds

0

+6

-6

arc-

seco

nd

s

1925

0 31 62 93 124

arc-seconds

0

+6

-6

arc-

seco

nd

s

1930

0 31 62 93 124

arc-seconds

0

+6

-6

arc-

seco

nd

s

1935

0 31 62 93 124

arc-seconds

0

+6

-6

arc-

seco

nd

s

1940

0 31 62 93 124

arc-seconds

0

+6

-6

arc-

seco

nd

s

1945

0 31 62 93 124

arc-seconds

0

+6

-6

arc-

seco

nd

s

1950

0 31 62 93 124

arc-seconds

0

+6

-6

arc-

seco

nd

s

1955

0 31 62 93 124

arc-seconds

0

+6

-6

arc-

seco

nd

s

Search for Companions Around SiriusJ.M. Bonnet-Bidaud , F. Colas and J. Lecacheux Astronomy and Astrophysics v360, 991-996 (2000)

4 arc-minutesor 1/15 degree

W

North

E