Update of Minor Planet Observations
Cumulative minor planet/comet observation and discovery
summary for all Tenagra telescopes (updated 2003 June 10)
Observatory code:
848 926
NEO observations: 1107
1641
Total observations: >2700
>5000
Minor planet discoveries: 11
130
Overview
Tenagra was originally conceived for supernovae discovery. But as it grew it became apparent that high quality minor planet and comet astrometry can be easily mixed in with other projects and deliver very important discovery and badly needed follow-up data.
Dr. Paulo Holvorcem, Director of Minor Planet and Comet Studies at Tenagra, has in one way or another been involved in Tenagra since its inception and now is responsible for all research design in these areas. This was made possible by his writing the most remarkable system called TAO which allows for the full scheduling of mixed (e.g. moving and stationary) targets. Therefore a typical run of a Tenagra telescope can include quasars and the latest NEO.
The Minor Planet Code for Oregon is 848. It is 926 for Arizona.
Since the inception of Tenagra II and some usage of the first Tenagra III our research design has been primarily follow ups on NEOs. Future programs will include these badly needed observations (especially for dim NEOs) but expand in its search for new objects.
An Example
In February 2001 Paulo Holvorcem observed on 8 nights on the old Tenagra III 0.5-m (now decommissioned), doing confirmation and follow-up of Near-Earth Objects (NEOs), and also searching for new asteroids near the anti-solar point. In this observing campaign about 50% of each night was dedicated to minor planet observations, and 50% to the LOTOSS supernova search program. In these 8 nights, Paulo obtained about 1400 CCD images, from which some 800 minor planet positional measurements were derived and reported to the MPC. During this period, it was possible to confirm and/or follow-up even the faintest and fastest NEOs discovered by the NEO surveys, the faintest of which was of 21st magnitude. These NEO observations were published in 23 Minor Planet Electronic Circulars between Feb. 15 and 28. Paulo discovered 40 new minor planets during the February campaign, most between magnitudes 19 and 21, including one of the smallest Trojan asteroids found so far, 2001 CD37.
This is a rather interesting graph summarizing results of this particular campaign:
In addition to showing the number of observations that can be made in a very short amount of time, this graph shows a relationship well known to NEO observers. The limiting magnitude detected by the 0.5-m F10 telescope for objects with motion rates slower than about 0.6 deg/day was around 21.3 under good conditions. For faster objects, the limiting magnitude decreases with the motion rate due to trailing losses. For example, for objects moving at 1 deg/day the effective limiting magnitude was about 20.7, and for objects moving at 10 deg/day it was about 18. This very nicely shows that if the telescope is tracking at a sidereal rate the movement of fast asteroids, usually NEOs, limits the ability to detect them since their light is "smeared" over a number of camera pixels during the exposure.
Another Example
This animation shows the NEO 1999 RQ36, a potentially hazardous asteroid, observed from Tenagra I during its closest approach to the Earth (about 2.3 million kilometers) on Sept. 23, 1999. At the time of these observations, the object was moving at about 13.5 deg/day.
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