THE MINOR PLANET BULLETIN OF THE MINOR PLANETS SECTION OF THE BULLETIN ASSOCIATION OF LUNAR AND PLANETARY OBSERVERS VOLUME 34, NUMBER 3, A.D. 2007 JULY-SEPTEMBER 53. CCD PHOTOMETRY OF ASTEROID 22 KALLIOPE Kwee, K.K. and von Woerden, H. (1956). Bull. Astron. Inst. Neth. 12, 327 Can Gungor Department of Astronomy, Ege University Trigo-Rodriguez, J.M. and Caso, A.S. (2003). “CCD Photometry 35100 Bornova Izmir TURKEY of asteroid 22 Kalliope and 125 Liberatrix” Minor Planet Bulletin [email protected] 30, 26-27. (Received: 13 March) CCD photometry of asteroid 22 Kalliope taken at Tubitak National Observatory during November 2006 is reported. A rotational period of 4.149 ± 0.0003 hours and amplitude of 0.386 mag at Johnson B filter, 0.342 mag at Johnson V are determined. The observation of 22 Kalliope was made at Tubitak National Observatory located at an elevation of 2500m. For this study, the 410mm f/10 Schmidt-Cassegrain telescope was used with a SBIG ST-8E CCD electronic imager. Data were collected on 2006 November 27. 305 images were obtained for each Johnson B and V filters. Exposure times were chosen as 30s for filter B and 15s for filter V. All images were calibrated using dark and bias frames Figure 1. Lightcurve of 22 Kalliope for Johnson B filter. X axis is and sky flats. JD-2454067.00. Ordinate is relative magnitude. During this observation, Kalliope was 99.26% illuminated and the phase angle was 9º.87 (Guide 8.0). Times of observation were light-time corrected. Reduction of frames was made with IRAF software. For differential photometry, GSC 1876 748 was used as a comparison star. The times of minima were computed by the Kwee-van Woerden method (Kwee & van Woerden, 1956). The rotational period for 22 Kalliope from the data presented is 4.149 ± 0.0003 hours. This is similar to the Trigo-Rodriguez (2003) value of 4.144 hours. The amplitude of lightcurve for filter B is 0.386 mag while the amplitude for filter V is 0.342 mag. Lightcurves are presented in Figure 1 for filter B and Figure 2 for filter V. Acknowledgments Figure 2. Lightcurve of 22 Kalliope for Johnson V filter. X axis is Many thanks to Tubitak National Observatory for use telescope JD-2454067.00. Ordinate is relative magnitude. time allocation and other facilities. References SUBSCRIPTION INCREASE NOTICE Guide 8.0 Software, http://www.planetpluto.com See page 55. Minor Planet Bulletin 34 (2007) Available on line http://www.minorplanetobserver.com/mpb/default.htm 54 PHOTOMETRY OF ATEN ASTEROID (66146) 1998 TU3 An eleven-point moving average was constructed for the phase plot, which gave an amplitude of 0.10 ± 0.01 mag, rather less than Tom Richards published figures, e.g. in Pravec et al (2005). The epoch used was Woodridge Observatory JD 2452919.2132 8 Diosma Rd Eltham, Vic 3095, Australia Fuller information may be found on the first author’s website, [email protected] http://www.woodridgeobsy.org. Greg Bolt References Craigie, WA, Australia Bembrick, C. (2005). “Asteroid Research and Amateur Input”. David Higgins Southern Stars, 44:3, 16-19. Hunters Hill Observatory Ngunnawal, Canberra ACT, Australia Binzel, R.P., Lupishko, D.F., Di Martino, M., Whiteley, R.J. and Hahn, G.J. (2002). “Physical Properties of Near Earth Objects” in Colin Bembrick Asteroids III (W. F. Bottke, A. Cellino, P. Paolicchi, R. P. Binzel, Mt Tarana Observatory eds.), pp. 255-271. Univ. Arizona Press, Tucson. Bathurst, NSW, Australia Harris, A.W., Warner, B.D. (2006). “Minor Planet Lightcurve (Received: 21 March ) Parameters”. http://cfa-www.harvard.edu/iau/lists/LightcurveDat.html Eleven sets of photometric data for (66146) 1998 TU3 were obtained over a 14 day period in 2003 October. A Hartley, M., Russell, K. S., Savage, A. Asher, D. J., Broughton, J., synodic rotation period of 2.3779 ± 0.0004 h with Hergenrother, C. W., Williams G. V., and Nakano, S. (1999). “1998 TU3” MPEC 1998 U03, available from amplitude 0.10 mag was derived, close to other http://adsabs.harvard.edu/abs/. published data. Higgins, D. (2007). “Minor Planet Lightcurves”. Minor planet (66146) 1988 TU3 was discovered by the LINEAR http://www.david-higgins.com/Astronomy/asteroid/lightcurves NEO survey on 1998 Oct 13. Orbital elements show it is an Aten .htm asteroid (Tesi et al 1998 and Hartley et al 1999). It has been assigned to the taxonomic class Q (Whiteley 2001) and based on its albedo its diameter is given at 3.6 km (Binzel et al 2002). Harris & Warner (2006) give a period of 2.375 h, referencing Világi (2002) and Pravec et al. (2005). Világi’s paper shows lightcurves from two nights in 2001 October, but provides no period. Pravec et al.’s table gives a period of 2.3767 ± 0.0009 h, listing Vilagi’s paper as the source. It also lists a period of 2.37741 ± 0.00004 h, from dates in Aug-Sep 2003 near those of the present study. For another discussion of some of the data in the present paper see (Bembrick, 2005). The present study was triggered by a request for observations of this earth-crossing asteroid at a close opposition. It consists of eleven observation sets, as follows, all obtained with unfiltered CCD cameras (except Higgins who used an R filter). Obs lists the observer’s initials (see author list above), and Data the number of data points in the observation set (with a total of 4689). Richards used an 18 cm refractor, Bolt a 25 cm SCT, Higgins a 25 cm SCT, Lightcurve for (66146) 1998 TU3, corrected for light-time and and Bembrick a 40 cm SCT. Higgins’s data and results are phased to 2.3779 h. available separately on his personal website (Higgins 2007) for which there is a quoted period of 2.37745 + 0.00005 h, as well as Date Obs Data Phase LPAB BPAB a phase plot. 1 2003.10.06 TR 638 29.8 7.4 -19.8 2 2003.10.06 GB 745 29.9 7.4 -19.8 All observations were corrected for light-time. Period analysis was 3 2003.10.07 GB 547 30.4 6.7 -19.7 carried out in Peranso 2.10 (Vanmunster, 2007). Numerous period 4 2003.10.08 GB 732 31.1 6.1 -19.7 analysis algorithms were applied, but ANOVA (Schwarzenberg- 5 2003.10.09 CB 162 31.8 5.5 -19.5 Czerny 1996) produced the minimum period error and visually the 6 2003.10.13 TR 115 35.8 2.9 -18.9 tightest phase plot, as shown in the Figure. The resulting period 7 2003.10.14 DH 267 37.0 2.3 -18.6 8 2003.10.15 GB 524 38.2 1.8 -18.4 was 2.3779 ± 0.0004 h, slightly higher than the published periods 9 2003.10.16 TR 506 39.4 1.4 -18.2 given above. A phase plot on the present data using the nearest 10 2003.10.17 TR 358 40.6 1.0 -18.0 published period figure of 2.37741 h, is noticeably less coherent. 11 2003.10.19 TR 95 43.1 0.2 -17.4 Minor Planet Bulletin 34 (2007) 55 Pravec, P., Wolf, M., and Sarounova, L. (2005). “Ondrejov Asteroid Photometry Project”, posted on http://www.asu.cas.cz/~ppravec/neo.htm. Schwarzenberg-Czerny, A. (1996). Ap J.460, L107-110. Tesi, L., Forti, G., Garradd, G. J., Broughton, J., Rogers, J. E. ,Blythe, M., Shelly, F., Bezpalko, M., Stuart, J., Viggh, H., Sayer, R., Griffin, I. P., Mendez, O., Scheck, J., Salvo, R., and Williams, G. V. (1998). “1998 TU3” MPEC 1999-C09, available from http://adsabs.harvard.edu/abs/ Vanmunster, T. (2007) “PERANSO Period Analysis and Light Curve Software”. http://users.skynet.be/fa079980/peranso/index.htm. Világi, J. (2002). “Asteroid photometry program at Modra Observatory” in Proceedings of Asteroids, Comets, Meteors – Figure 1. Dramatic upturn in number of asteroid rotations reliably ACM 200, pp. 907-910. known. (Figure credit: Alan W. Harris). Whiteley, R.J. (2001). A Compositional and Dynamical Survey of the Near-Earth Asteroids. PhD. Thesis, University of Hawaii. THE PRICE OF SUCCESS: SUBSCRIPTION RATE INCREASE FOR THE MINOR PLANET BULLETIN You hold in your hands the largest issue produced to date in the history of the Minor Planet Bulletin. 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