Interamnia Occultations Observed before 2003

Updated: 2003 April 3

The 2003 March 23rd occultation is the best-observed one involving 
(704) Interamnia, but it's not the first!  Below is a list of 
previously-observed occultations by this large asteroid; "p" is the 
number of photoelectric or video chords and "v" is the number of 
visual chords:

   D a t e     S t a r    mag.    Location         Observer   p v Ref.
1984 Aug. 05  L 9443-24   13.5 TableMt.Obs.,Calif. Jim Young  1 0 Stamm 1984     >140
1990 Dec. 09  FAC 900107  11.3 Pittsburgh, Penn.   F. Graham  0 1 Stamm 1991b 
1995 Dec. 06  GSC18700396 11.5 Okayama City, Japan N. Ohkura  1 0 Sato 1996      >343
1996 Dec. 17  BD +3d 633   9.5 Calif.,Ariz.,N.Mex. >9 +2 miss 7 4 Dunham 1996 337.8x321.2

References and notes:

1984:  The observed chord length was 140 km.  Published by Jim Stamm in 
   "Observations of asteroidal appulses and occultations" in Occultation 
   Newsletter Vol. 3, pp. 185-187 (1984).

1990:  There are some doubts about this visual observation, published by
    Jim Stamm in "Reports of asteroidal appulses and occultations" in 
    Occultation Newsletter Vol. 5, pp. 93-94 (1991).

1995:  The observed chord length was 343 km.  Published by Isao Sato in 
   his Ph.D. thesis, "Asteroidal Occultation Observations from Japan"
   (1996).

1996:  We have observations of this occultation from 9 stations in the 
southwestern USA; the 2 closest (on the south side) miss observations 
are also included in a list that is explained here.  
In addition, photoelectric or CCD observations were made from 2 or 3 
mobile stations from Lowell Observatory set up between Flagstaff and 
Phoenix, Arizona, but those observations have not been reported.  
The available observations were fitted with the following ellipse:
Semi-major axis, 168.4 +/-2.3 km; semi-minor axis, 160.6 +/-2.3 km; 
P.A. of minor axis, 12.4 +/-26.2 deg.; X center, -310.1 +/-4.4 km; and 
Y center, -83.0 +/-2.8 km.  In a plot, with a Word version 
of it here, video chords end in small o's, while visual 
chords end in +'s; the chord numbers correspond to the stations in 
the list.  The two lines with numbers 200 and 201 are the closest 
miss observations, not chords.  David Herald has made a 
slightly different plot of the observations. 

David Dunham