This is an international project whose main purpose is to discover possible cometary features among asteroidal population having a Tisserand parameter respect to Jupiter (Tj) less than 3.
T=3 is approximately the boundary between asteroidal and cometary orbits, according to Levison H. F., Comet Taxonomy, in Completing the Inventory of Solar System, ASP Conference Series Vol. 107, T. W. Rettig and J. M. Hahn eds. (1996).
We’ve presented this program at MACE 2006 in Wien, our presentation is visible here:
Presentation at MACE 2006 (PDF file, 235 kB)
First of all a complete list of suitable targets will be sent to the observers by the coordinator Luca Buzzi usually twice a month. Then the observing strategy is quite simple: you have to image these minor planets (possibly only in good seeing for your location) and all the good frames collected must be normalized (bias and dark frame subtraction and possibly flat-field calibration).
Then, with Astrometrica, you have to stack all your calibrated frames according to the motion of the asteroid. If the cometary feature is not visible by visual inspection of the risulted stack, you have to measure the FWHM of the object. If this value is at least 20% greater than stars of similar SNR, you’re probably in presence of a coma.
Please note that the SNR of the object must be the highest possible in order to avoid false detections, always possible with the average seeing of many amateur observing sites.
WHAT DO I REPORT ?
Every observed object, in which cometary feature is NOT seen, must be measured in the traditional way and sent to the MPC. Information must be also sent to the coordinator with some comments about the observation.
In case a cometary feature *IS SEEN*, you must contact our internal mailing-list (for those who wants to join please contact me) sending the batch of the measures together with an image, the FWHM of the object and the comparison star and the SNR of the object. If you want, you can send also a word to the MPC (only if you are sure of your finding), specifying that you belong to the T3 Project.
Example of report:
CON S. Foglia, C.Gariboldi 11, I-28100 Novara Veveri, Italy [firstname.lastname@example.org]
OBS D. Crespi, S. Foglia, G. Galli, S. Minuto
MEA S. Foglia, G. Galli
TEL 0.40-m f/4 reflector + CCD
ACK 2005 SB216 possible cometary feature
COM FWHM object= 4.0″ (SNR=7.6) while FWHM stars = 2.8″
K05SL6B C2005 12 29.78898 00 28 12.43 +14 26 54.0 18.9 147
Also negative reports are very useful for planning future observations.
LIST OF PARTECIPIANTS:
Luca Buzzi – Schiaparelli Observatory, Italy – MPC 204
Sergio Foglia – Astronomical Research Institute, USA – MPC H21
Gianluca Masi – Ceccano, Italy – MPC 470
Gianni Galli – GiaGa Observatory, Italy – MPC 203
Maura Tombelli – Montelupo, Italy – MPC 108
Raoul Behrend – University of Geneve-La Silla Observatory, Chile – MPC 809
Rolando Ligustri – CAST Observatory, Italy – MPC 235
Enrico Prosperi – Castelmartini, Italy – MPC 160
Robert Holmes – Astronomical Research Institute, USA – MPC H21
Paolo Bacci – Capannoli, Italy – MPC B09
Charles Bell – Vicksburg, USA – MPC H47
Leonid Elenin – ISON-NM, USA – MPC H15
Hidetaka Sato – GRAS, USA – MPC H06 – I89
Gonzalo Tancredi – Los Molinos, Uruguay – MPC 844
Sebastian Bruzzone – Los Molinos, Uruguay – MPC 844
Zhongyi Lin – Lulin Observatory, Taiwan – MPC D35
More informations can be found in the UAI asteroid webpage maintained by Sergio Foglia (MPC 147).