TRAPPIST comet production rates: C/2017 K2 (PanSTARR), C/2021 E3 (ZTF), and 22P/Kopff
ATel #15491; E. Jehin, M. Vander Donckt, S. Hmiddouch, J. Manfroid, H. Hutsemekers (STAR Institute, University of Liege), and Y. Moulane (Auburn University)
on 1 Jul 2022; 15:16 UT
Credential Certification: Emmanuel Jehin (ejehin@uliege.be)
The authors report that they obtained from TRAPPIST-South (code=I40, la Silla Chile) robotic telescope (Jehin el al. 2011) recent observations using cometary HB narrowband filters (Farnham et al. 2000) for the following comets and computed preliminary production rates at 10.000 km using a Haser Model (Vp=Vd=1km/s) (Haser 1957). The dust production rates proxy A(0)f(rho) were estimated by profile fitting at 10.000 km (A'Hearn et al. 1984) and corrected for the phase angle (Schleicher 2007).
C/2017 K2 (PanSTARRS)
Date UT=2022-06-28, r_h=2.78 au, Delta=1.86 au, DT=-174 days
Q(OH)=(3.78+/-0.66) E28 s-1; Q(CN)=(2.09+/-0.13) E26 s-1; Q(C3)=(5.15+/-0.57) E25 s-1; Q(C2)=(1.88+/-0.42) E26 s-1
A(0)fp(RC)=6690+/-159 cm
C/2021 E3 (ZTF)
Date UT=2022-06-28, r_h=1.79 au, Delta=1.49 au, DT=+17 days
Q(OH)=(1.53+/-0.32) E28 s-1; Q(CN)=(4.96+/-0.28) E25 s-1; Q(C2)=(4.62+/-0.40) E25 s-1
A(0)fp(RC)=456+/-17 cm
22P/Kopff
Date UT=2022-06-29, r_h=1.86 au, Delta=1.68 au, DT=+103 days
Q(OH)=(2.82+/-0.63) E27 s-1; Q(CN)=(1.20+/-0.06) E25 s-1; Q(C2)=(1.27+/-0.09) E25 s-1
A(0)fp(RC)=114+/-8 cm
Notations: r_h= heliocentric distance (in au), Delta=geocentric distance (in au), DT= Time to perihelion. OH, NH, C3, CN, C2 are the HB gaseous narrowband filters for the corresponding species, and BC, GC, RC are the blue, green and red dust continuum filters (Farnham et al. 2000)
Acknowledgments: TRAPPIST is a project funded by the Belgian F.R.S.-FNRS under grant PDR T.0120.21. Observations were carried on from the ESO La Silla Paranal Observatory. We thank NASA, David Schleicher and the Lowell Observatory for the loan of the HB comet filters.
