Follow-up Imaging Observations of Comet 240P and its fragment 240P-B
ATel #17537; M. Mugrauer (AIU Jena), M. Belger (AIU Jena), Z. Jamil (AIU Jena), K.-U. Michel (AIU Jena), B. Dincel (AIU Jena), S. Aruna Ravi (AIU Jena), M. Jory (AIU Jena), S. Mahagaon (AIU Jena), G. Payli (AIU Jena), C. Soltmann (AIU Jena)
on 10 Dec 2025; 16:45 UT
Credential Certification: Markus Mugrauer (markus@astro.uni-jena.de)
Referred to by ATel #: 17665
Between 30 October and 3 December 2025, we conducted follow-up imaging observations of comet 240P and its fragment 240P-B (MPEC2025-T124) in seven observation epochs, using the Schmidt-Teleskop-Kamera (STK), which is operated in the Schmidt focus of the 90 cm telescope at the University Observatory Jena. In each epoch, at least ten STK images were taken with a detector integration time of 60 s in the R-band. We measured the astrometry of the comet and its fragment and determined the R-band brightness of both objects using aperture photometry. During our observation campaign, the fragment was located southwest of 240P at a mean position angle of 236.0 ± 0.5 °. The angular separation of the fragment from the comet increased from 111.8 ± 0.7 arcsec to 120.2 ± 0.2 arcsec, while the distance of 240P from Earth decreased from 1.24 to 1.16 au. The mean projected separation of the fragment from 240P was 100910 ± 390 km. The brightness of the comet and its fragment in the R-band increased during our observation campaign. While 240P only became 0.50 ± 0.14 mag brighter, the R-band brightness of the fragment increased by 2.34 ± 0.15 mag, while its distance from the Sun decreased from 2.16 to 2.13 au.
Follow-up Imaging Observations of Comet 240P and its fragment 240P-B - Online Data
