Basic Planet Information for 2005


Planetary Diameters (in arc sec) at mid-month (i.e. 15th)

                Mars     Jupiter    Saturn    Uranus

2005 January     4.3       36.4      19.5       3.4
     February    4.8       39.9      19.3       3.3     Semester 05A
     March       5.4       42.2      18.7       3.3
     April       6.3       42.7      17.7       3.4
     May         7.2       40.7      16.8       3.4
     June        8.5       37.4      16.2       3.5
     July       10.2       34.2      15.9       3.6
     August     12.5       31.8      16.0       3.7     Semester 05B
     September  15.8       30.2      16.4       3.7
     October    19.4       29.6      17.1       3.6
     November   19.2       30.0      18.1       3.5
     December   14.5       31.2      19.1       3.4


Total 850-micron flux densities in beam (Jy) at mid-month *

                Mars     Jupiter    Saturn    Uranus

2005 January     260       3029      1722      59.7
     February    325       3046      1691      58.4     Semester 05A
     March       409       3051      1623      58.5
     April       540       3052      1529      59.9
     May         713       3048      1444      62.4
     June        958       3035      1381      65.6
     July       1288       3009      1352      68.5
     August     1783       2971      1359      70.5     Semester 05B
     September  2460       2937      1402      70.5
     October    3009       2920      1475      68.7
     November   2858       2858      1567      65.6
     December   1999       2959      1651      62.4

     * Using nominal beamwidth at 850 microns (14.5")

Approximate transit times (HST) at mid-month **

                Mars     Jupiter    Saturn    Uranus

2005 January   (09:34)   05:52      00:25    (15:09)
     February   09:07    03:51      22:13    (13:13)    Semester 05A
     March      08:43    01:52      20:17    (11:28)
     April      08:13    23:35      18:18    (09:32)
     May        07:39    21:27     (16:28)    07:38
     June       06:59    19:23     (14:40)    05:37
     July       06:14    17:31     (12:56)    03:37
     August     05:20   (15:45)    (11:11)    01:31     Semester 05B
     September  04:03   (14:05)     09:24     23:25
     October    02:06   (12:30)     07:36     21:23
     November   23:23   (10:54)     05:39     19:19
     December   21:08    09:18      03:39    (17:22)

     ** Times in parentheses indicate transit during the `day-time'
        (outside normal operating hours)

Summary: Mars is once again available throughout the semester, mostly 
in the mornings. Jupiter is at opposition in March/April. Saturn is 
unavailable for part of the Summer; Uranus OK Spring until early 
Winter as always.

Henry Matthews
19 January 2004