Hubble search for transition comets (Transition Comets—UV Search for OH Emissions in Asteroids) was a study involving amateur astronomers and the use of the Hubble Space Telescope, one of only six studies involving amateur astronomers approved by NASA.
[2] In December 1985, the leaders of seven national amateur astronomy organizations met at STScI in Baltimore to discuss the participation of amateur astronomers in the HST project: The team used the Hubble Space Telescope to perform a spectroscopic search for OH emission from five asteroids.
Concurrently with the spectroscopic study, ground-based visual observations were carried out by 80 amateur astronomers in 22 countries.
It would appear that some would eventually use all of their volatiles, or perhaps cover these under a blanket of dust after repeated passages around the Sun.
These two asteroids were selected because of the nature of their orbits, their meteor-shower associations, and their other characteristics (see Weissman et al. (1989) for a full discussion of their comet-like features).
The asteroids 182 Elsa, 224 Oceana, and 899 Jokaste were also observed with the Faint Object Spectrograph, and with the same spectral element G270H.
Ground-based observations of these two objects were limited to several CCD images of the area in which 2201 Oljato was calculated to appear.
Ground-based observations of 182 Elsa, 224 Oceana, and 899 Jokaste were conducted visually, photographically, with VHS, and with CCD equipment.
Studies of nearby stars on the original image suggest that this was due to a small amount of trailing during guiding.
Observations of 944 Hidalgo and 2201 Oljato had to be conducted before the Hubble Space Telescope servicing mission.
The Hubble Space Telescope, using the same Faint Object Spectrograph and spectral element G270H, also failed to find any evidence of OH from SL-9.
The main-belt asteroids 224 Oceana, 182 Elsa, and 899 Jokaste were observed near opposition, but did not show any evidence of OH emission.
The last two were observed when the Hubble Space Telescope was having guidance problems, and had to present special orientation to the Sun due to the loss of one solar panel.