Binzel Award
Automated Minor Planet Light Curve
Software Bisque was the recipient of the
the Binzel Award (see reference at the bottom of page). For the last 10 years a prize of an expensive
bottle of wine was offered to anyone who could completely
automate the process of acquiring CCD images and automatically reducing the data
presented in the form of a minor planet light curve. NOTE: This same
procedure will work with Variable Stars and Eclipsing binaries as well.
The data was automatically collected using
a Paramount GT-1100S with a
Celestron C-11 at f/10 that was
controlled with Software Bisque's Observatory Suite software. The SBIG
ST-9E CCD
imaging camera was used. CCDSoft version 5
automatically
reduced the data. Two minor planets
were imaged and reduced in the same night and two rare vintage bottles of wine
were awarded to Software Bisque, one for each light curve.
Automated Minor Planet
Light Curve Generation
July 20, 2001
Matthew L. Bisque
Daniel R. Bisque
Stephen M. Bisque
Thomas M. Bisque
Software Bisque
912 Twelfth Street
Golden, CO 80401
The system described within autonomously
generates a light curve for one or more desired minor planets.
Specifically, the automated process was started with the press of
a button, it ran during the night, and the next morning the
computer screen displayed the light curves.
This paper presents an automated system
that generates a light curve for one or more minor planets. In
short, the system allows one to "Press the start button at
the beginning of the night, go to bed, and have the minor planet
light curve greet you in the morning." Specifically, this
method meets the challenge put forth by Professor Richard P.
Binzel.
System Overview
1. Object Lookup/Minor Planet Orbital
Integration
2. Control Telescope
3. Point Telescope
4. Control Camera
5. Compute Light Curve
6. Graph Light curve
The components of the system include: a
celestial object database program capable of resolving the name of a of minor
planet to its position, and providing positions of stars for
astrometry and photometry purposes; a telescope control
and modeling program
that controls the robotic
telescope hardware and accurately
positions the telescope by accounting for systematic telescope errors;
a camera control and
image processing program capable of controlling a camera and computing astrometry and photometry for raw
light curve data;
a graphing program capable
of displaying the light curve graph from the raw data.
The celestial object database program can
be commanded externally to provide the position of any named
minor planet. The list of all known minor planets maintained by
the Minor Planet Center
can be easily incorporated into the database program so that the
position of any minor planet can be resolved. Orbital integration
is used to produce a very accurate minor planet position. This
program also serves as a database for reference stars for
astrometry and photometry purposes.
The telescope control program can be
commanded externally to move the telescope to any desired
position. Integrated with the telescope control program is
telescope modeling to correct for systematic errors common to
most every telescope mechanical system. The major systematic
errors include out of round gears, non-perpendicular axis, polar
misalignment, mechanical flexures and offset errors. The
telescope-modeling program quantifies and rigorously corrects for
these systematic errors, enabling the telescope to point to the
desired minor planet.
The camera control program can be
externally commanded to acquire digital images. The
image-processing portion of this program analyses the images
acquired. An astrometric solution is generated by recognizing and
correlating stellar patterns on the image itself along with
stellar patterns in the associated field of the celestial object
database program. Through astrometry of the image and the
celestial object database program, appropriate reference stars
are used, their flux noted, along with the minor planet’s
flux. It should also be noted that as the images are acquired,
they are reduced accounting for bias and dark current. Then a
flat field is applied.
System Integration
At the beginning of the night, the
process was initiated by the press of a button. The celestial
object database program resolved the name of the first minor
planet to a position. The telescope control and modeling program
instructed the telescope to slew to this minor planet position.
The camera control and image-processing program, acquired an
image of the minor planet, reduced the image, computed an
astrometric solution, and logged the instrument magnitudes of the
reference stars and the minor planet. This process was repeated
throughout the night while slewing between the two minor planets
until a specified time at which the logged data was displayed on
screen. The light curves for the two minor planets are shown in
Figure 1 and Figure 2.
The system successfully met the challenge
at hand by automating the process of generating a light curve for
two minor planets. It could be easily adapted to apply to most
any type of celestial object, for example variable stars and
satellites.
Figure 1
Automated Light Curve for Minor Planet
Philippina.
Figure 2
Automated Light Curve for Minor
Planet Asporina.
1 Binzel, R. P. (1992). "Robotic Observations
of Asteroids." In Robotic Observatories: Present and Future,
(S. Baliunas and J. Richard, eds.). Fairborn Press, Arizona. 1992
Example ST-9E CCD image
of minor planet (246) Asporina
C-11 f/10 ST-9E Paramount GT-1100S
Next the image is automatically
aligned in TheSky using Image Link pattern recognition technology.
TheSky Display
Easy object identification
directly on top of the image
Computed data for Asporina by
TheSky.
246 Asporina
Distance from Earth: 1.468710 astronomical units.
Distance from Sun: 2.450118 astronomical units.
Heliocentric: l:-64.2641 b:11.5392 r:2.4501
Magnitude: 12.0
Rates ra: -0.0088 dec: -0.0050 (arc-secs/sec)
Magnitude: 12.0
RA: 19h 39m 26.1s Dec: -01°41'29"
RA: 19h 39m 21.3s Dec: -01°41'42" (Epoch 2000)
Azm: 182°47'38" Alt: +48°31'39"
Rise: 01:03 Transit: 07:00 Set: 12:56
Hour angle: 00h 07m 29.0s Air mass: 1.33
The following image shows the
astrometry performed on one of the minor planet images using TheSky6.
One mouse click Astrometry!
Astrometric solution 0.06 arcseconds RMS!
The yellow markers
indicate the stars being used in the astrometric solution.
The above minor planet #12934 was graciously named
for the Bisque brothers by one of our very successful
and first
Paramount customers.
At the time of this writing Dr. Juels has made well over 500 minor planet
designations to date and over 150+ official minor planet discoveries. He
decided to name is first official discovery minor planet "Bisque".
That is quite an honor.
One of the telescopes used
by Dr. Juels is a custom built 12.5 inch
Newtonian (similar to the
one
shown here) which is mounted on the
Paramount GT-1100S.
See the following discoveries page
for additional discoveries
being made by our customers. The following page has additional
information and images show how the mount will track fast moving
Near Earth Asteroids (NEO's) Tracking Near Earth Asteroids.
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