61

PHOTOMETRIC OBSERVATIONS OF diameter is 49.863 ± 0.975 km based on an absolute magnitude MAIN-BELT , 1117 REGINITA, H = 10.25 (JPL, 2018). AND (11200) 1999 CV121. Observations at all three observatories were made on 11 nights Charles Galdies from 2018 May 6 to July 12. We obtained a synodic period of Znith Observatory 21.901 ± 0.001 hr and amplitude of 0.14 ± 0.02 mag. These results Armonie, E. Bradford Street, are consistent with previously published results from Ruthroff Naxxar NXR 2217, MALTA (2009), Pilcher (2014), and Stephens (2014). [email protected]

Stephen M. Brincat Flarestar Observatory (MPC 171) San Gwann SGN 3160, MALTA

Winston Grech Antares Observatory Fgura FGR 1555, MALTA

(Received: 2018 Oct 1)

Photometric observations of three main-belt asteroids were obtained from 2018 April-July from Malta in order to determine their synodic rotation periods. We provide lightcurves for 232 Russia and 1117 Reginita that were obtained from the Spin/Shape Modeling Opportunities list by Warner et al. (2018). The (11200) 1999 CV121 did not have a referenced period in the LCDB database (Warner et al., 2009). 1117 Reginita is a main-belt asteroid discovered on 1972 May 24 Photometric observations of three main-belt asteroids were carried by J. Comas Sola in Barcelona, Spain. This 10.193 ± 0.250 km out from three observatories located in Malta (Europe). diameter asteroid has an absolute magnitude H = 11.7 and orbits Observations of asteroids 232 Russia, 1117 Reginita, and (11200) the with a semi-major axis of 2.248, eccentricity of 0.198, and 1999 CV121 were obtained from 2018 April-July. Znith period of 3.37 years (JPL, 2018). Observatory employed a 0.20-m Schmidt-Cassegrain (SCT) equipped with a Moravian G2-1600 CCD camera at 1x1 binning; Flarestar Observatory used the same CCD model coupled with a 0.25-m SCT, also at 1x1 binning; Antares Observatory used an SBIG STL-11000 CCD camera binned 2x2 attached to a 0.28-m SCT. All cameras were cooled to –15°C. The science images were dark subtracted and flat-fielded.

All telescopes and cameras were controlled remotely from a location near each telescope via Sequence Generator Pro (Binary Star Software). Photometric reduction, lightcurve construction, and analyses were done using MPO Canopus (Warner, 2017) and differential aperture . The Comparison Star Selector (CSS) feature of MPO Canopus was used to select comparison stars of near-solar color. Measurements were based on the CMC- 15 catalogue with magnitudes converted from J-K to BVRI (Warner, 2007).

(232) Russia is a large main-belt asteroid that was discovered on 1883 January 31 by in ; it was suggested as a possible target in order to derive spin/shape models (Warner et al., Observations were made on three nights from 2018 May 31 to 2018). It orbits the Sun with a semi-major axis of 2.553 AU, June 6. Each observatory contributed one session. Our results eccentricity 0.175, and period of 4.08 years (JPL, 2018). The indicate a synodic period of 2.9478 ± 0.0003 hr and amplitude of 0.17 ± 0.02 mag. These are consistent with previously published

Number Name 2018 mm/dd Pts Phase LPAB BPAB Period(h) P.E. Amp A.E. Grp 232 Russia 05/06-07/12 554 8.2,27.1 220 +8 21.901 0.001 0.14 0.02 MB-I 1117 Reginita 05/31-06/06 170 5.7,8.4 245 +7 2.9478 0.0003 0.17 0.02 FLOR 11200 1999 CV121 04/23-07/12 286 4.9,26.7 220 +1 6.792 0.001 0.29 0.05 MB-M

Table I. Observing circumstances and results. Pts is the number of data points. The phase angle is given for the first and last date. LPAB and BPAB are the approximate phase angle bisector longitude and latitude at mid-date range (see Harris et al., 1984). Grp is the /group (Warner et al., 2009). MB-I/M: main-belt inner/middle; FLOR: Flora.

Minor Planet Bulletin 46 (2019) 62 periods from Wisniewski et al. (1997), Behrend (2007), References Kryszczynska et al. (2012), Chang et al. (2015). Waszczak et al. (2015), and Tan et al. (2017). Behrend, R. (2007). CdL Observatoire de Geneve web site: http://obswww.unige.ch/~behrend/page_cou.html (11200) 1999 CV121 is a main-belt asteroid discovered on 1999 Accessed: 2018 September 26. February 11 in Socorro (New Mexico) as part of the LINEAR (Lincoln Near-Earth Asteroid Research) project conducted in Chang, C.-K., Ip, W.-H., Lin, H.-W., Cheng, Y.-C., Ngeow, C.-C., collaboration with the US Air Force, NASA, and the Laboratory Yang, T.-C., Waszczak, A., Kulkarni, S.R., Levitan, D., Sesar, B., Lincoln of the Massachusetts Institute of Technology. Laher, R., Surace, J., Prince, T.A. (2015). “Asteroid Spin-rate Study Using the Intermediate Palomar Transient Factory.” Ap. J. This asteroid orbits the Sun with a semi-major axis of 2.738 AU, Suppl. Ser. 219, A27. eccentricity 0.215, and period of 4.53 years (JPL, 2018). JPL (2018) lists the diameter as 9.137 ± 0.081 km based on an absolute Harris, A.W., Young, J.W., Scaltriti, F., Zappala, V. (1984). magnitude H = 12.2. “Lightcurves and phase relations of the asteroids 82 Alkmene and 444 Gyptis.” Icarus 57, 251-258. 1999 CV121 was observed at all observatories from 2018 April 23 through June 18. Our results include a synodic period of 6.792 ± JPL (2018). Small-Body Database Browser - JPL Solar System. 0.001 hr and amplitude of 0.29 ± 0.05 mag. The lightcurve Dynamics web site. http://ssd.jpl.nasa.gov/sbdb.cgi database (LCDB; Warner et al., 2009) did not contain any Accessed: 2018 September 26. references with a for this asteroid. Kryszczynska, A., Colas, F., Polinska, M., Hirsch, R., Ivanova, V., Apostolovska, G., Bilkina, B., Velichko, F.P., Kwiatkowski, T., Kankiewicz, P. and 20 coauthors. (2012). “Do Slivan states exist in the Flora family? I. Photometric survey of the Flora region.” Astron. Astrophys. 546, A72.

Pilcher, F. (2014). “Another Asteroid with a Changing Lightcurve: 232 Russia.” Bull. 41, 205.

Ruthroff J.C. (2009). “Photometric Observations and Lightcurve Analysis of Asteroids 129 Antigone, 174 Phaedra, 232 Russia, , and 343 Ostara.” Minor Planet Bull. 36, 121-122.

Stephens, R.D. (2014). “Asteroids Observed from CS3: 2014 April-June.” Minor Planet Bull. 41, 226-230.

Tan, H., Li, B., Gao, X. (2017). “The Rotation Period of 1117 Reginita.” Minor Planet Bull. 44, 307.

Warner, B.D. (2007). “Initial Results of a Dedicated H-G Acknowledgements Program.” Minor Planet Bull. 34, 113-119.

We would like to thank Brian Warner for his work in the Warner, B.D., Harris, A.W., Pravec, P. (2009). “The asteroid development of MPO Canopus and for his efforts in maintaining lightcurve database.” Icarus 202, 134-146. Updated 2018 June 23. the CALL website (Warner, 2016). http://www.MinorPlanet.info/lightcurvedatabase.html

This research has made use of the JPL’s Small-Body Database. Warner, B.D. (2016). Collaborative Asteroid Lightcurve Link website. http://www.minorplanet.info/call.html Accessed: 2018 September 26.

Warner, B.D. (2017). MPO Software, MPO Canopus version 10.7.10.0. Bdw Publishing. http://www.minorplanetobserver.com/

Warner, B.D., Harris A.W., Durech J., Benner L.A.M. (2018). “Lightcurve photometry opportunities: 2018 April-June.” Minor Planet Bull. 45, 208-213.

Waszczak, A., Chang, C.-K., Ofek, E.O., Laher, R., Masci, F., Levitan, D., Surace, J., Cheng, Y.-C., Ip, W.-H., Kinoshita, D., Helou, G., Prince, T.A., Kulkarni, S. (2015). “Asteroid Light Curves from the Palomar Transient Factory Survey: Rotation Periods and Phase Functions from Sparse Photometry.” Astron. J. 150, A75.

Wisniewski, W.Z., Michalowski, T.M., Harris, A.W., McMillan, R.S. (1997). “Photometric Observations of 125 Asteroids.” Icarus 126, 395-449.

Minor Planet Bulletin 46 (2019)