Transcript ppt

Orbital Motion
Sirius A and Sirius B
Sirius A
Sirius B
Center
of mass
Orbital Motion Sirius A and Sirius B
Orbital plane (looking at an angle)
Orbital plane (looking perpendicular to
the orbital plane along the red arrow)
Sirius A
Sirius B
Center
of mass
Orbital Motion Sirius A and Sirius B
Plane of the Sky
0
31
62
93
124
arc-seconds
Sirius A
Sirius B
Center
of mass
1850
Sirius A on the sky
arc-seconds
+6
0
-6
0
31
62
93
124
arc-seconds
Sirius A and B in space
1855
arc-seconds
+6
0
-6
0
31
62
arc-seconds
93
124
1860
arc-seconds
+6
0
-6
0
31
62
arc-seconds
93
124
1865
arc-seconds
+6
0
-6
0
31
62
arc-seconds
93
124
1870
arc-seconds
+6
0
-6
0
31
62
arc-seconds
93
124
1875
arc-seconds
+6
0
-6
0
31
62
arc-seconds
93
124
1880
arc-seconds
+6
0
-6
0
31
62
arc-seconds
The "center of mass"
will remain fixed in the
following slides.
Watch the orbits
carefully.
93
124
1885
arc-seconds
+6
0
-6
0
31
62
arc-seconds
93
124
1890
arc-seconds
+6
0
-6
0
31
62
arc-seconds
93
124
1895
arc-seconds
+6
0
-6
0
31
62
arc-seconds
93
124
1900
arc-seconds
+6
0
-6
0
31
62
arc-seconds
93
124
1905
arc-seconds
+6
0
-6
0
31
62
arc-seconds
93
124
1910
arc-seconds
+6
0
-6
0
31
62
arc-seconds
93
124
1915
arc-seconds
+6
0
-6
0
31
62
arc-seconds
93
124
1920
arc-seconds
+6
0
-6
0
31
62
arc-seconds
93
124
1925
arc-seconds
+6
0
-6
0
31
62
arc-seconds
93
124
1930
arc-seconds
+6
0
-6
0
31
62
arc-seconds
93
124
1935
arc-seconds
+6
0
-6
0
31
62
arc-seconds
93
124
1940
arc-seconds
+6
0
-6
0
31
62
arc-seconds
93
124
1945
arc-seconds
+6
0
-6
0
31
62
arc-seconds
93
124
1950
arc-seconds
+6
0
-6
0
31
62
arc-seconds
93
124
1955
arc-seconds
+6
0
-6
0
31
62
arc-seconds
93
124
North
W
E
4 arc-minutes
or 1/15 degree
Search for Companions Around Sirius
J.M. Bonnet-Bidaud , F. Colas and J. Lecacheux
Astronomy and Astrophysics v360, 991-996 (2000)