88 # Name Date Range Per Amp Phase L-PAB B-PAB PE (yyyy/mm/dd) (h) (mag) AE 494 Virtus 2008/03/15–2008/04/05 5.9 166.7 7.1 5.570 0.003 0.033 0.005 556 Phyllis 2008/10/13–2008/11/14 7.6 31.3 6.3 4.2909 0.0003 0.222 0.005 624 Hektor 2008/12/29–2009/01/28 15.4 20.2 12.5 6.9210 0.0001 0.590 0.005 657 Gunlod 2008/12/01–2009/01/01 6.2 87.7 6.9 15.6652 0.0001 0.193 0.003 1111 Reinmuthia 2009/01/25–2009/02/14 9.0 107.8 -1.6 4.0075 0.0001 0.945 0.003 1188 Gothlandia 2008/12/10–2009/01/07 14.2 74.7 6.6 3.4915 0.0001 0.776 0.005 1376 Michelle 2008/10/01–2008/10/21 8.8 5.3 -2.4 5.9748 0.0002 0.199 0.003 Minor Planet Bulletin 36 (2009)
89 5905 JOHNSON: A HUNGARIA BINARY Brian D. Warner Palmer Divide Observatory/Space Science Institute 17995 Bakers Farm Rd., Colorado Springs, CO USA 80908 brian@<strong>MinorPlanet</strong>Observer.com Alan. W. Harris Space Science Institute, La Canada, CA USA Petr Pravec Astronomical Institute, Academy of Sciences Ondřejov, CZECH REPUBLIC Walter R. Cooney, Jr., John Gross, Dirk Terrell Sonoita Research Observatory, Sonoita, AZ USA Julian Oey Leura Observatory, Leura, NSW, AUSTRALIA Jozef Vilagi, Stefan Gajdos Modra Observatory Dept. of Astronomy, Physics of the Earth and Meteorology Bratislava, SLOVAKIA James W. Brinsfield Via Capote Observatory, Thousand Oaks, CA USA Joseph Pollock Physics and Astronomy Dept., Appalachian State Univ. Boone, NC USA Daneil Reichart, Kevin Ivarsen, Josh Haislip, Aaron LaCluyze, Melissa Nysewander PROMPT, UNC-Chapel Hill, NC USA Franck Marchis, Minjin Baek SETI Institute & Univ. of California at Berkeley, CA USA (Received: 2009 Apr 7) The Hungaria asteroid, 5905 Johnson, was previously confirmed to be a binary system. Follow up observations were obtained by the authors during a 2008 campaign in order to further define the system. The data from this second campaign found the rotation of the primary P 1 = 3.7826 ± 0.0002 h. The orbital period was P orb = 21.78 ± 0.01 h. occultations (“mutual events”) are seen as attenuations superimposed on the combined curves (see Pravec et al., 2006). His results for the 2008 campaign are posted in the Table 1. In 2008, some deviations from the P 1 /P orb model indicated the possibility of a third period, which – if real – could be interpreted as the rotation of the satellite or, less likely, the rotation of a third body in the system. However, a careful examination of the data showed no consistent signal and the deviations may just be noise. A second look of the 2005 data shows no signs of a third period. Acknowledgements Funding for observations at the Palmer Divide Observatory is provided by NASA grant NNG06GI32G, National Science Foundation grant AST-0607505, and by a Gene Shoemaker NEO Grant from the Planetary Society. The work at Ondřejov was supported by the Grant Agency of the Czech Republic, Grant 205/05/0604. References Pravec, P., Scheirich, P., Kušnirák, P., Šarounová, L., and 53 coauthors (2006). “Photometric Survey of Binary Near-Earth Asteroids.” Icarus 181, 63-93. Warner, B., Pravec, P., Kusnirak, P., Pray, D., Galad, A., Gajdos, S., Brown, P., and Krzeminksi, Z. (2005a) IAUC 8511. Warner, B.D., Pravec, P., Harris, A.W., Galad, A., Kusnirak, P., Pray, D.P., Brown, P., Krzeminski, Z, Cooney, Jr., W., Gross, J., Terrell, D., and 8 colleagues. (2005b) Abstracts, ACM 2005. Observatorio Nacional, Rio de Janeiro. 5905 Johnson (2008 Results) P1 3.7826 ± 0.0002 h P(orb) 21.78 ± 0.01 h A1 0.08 ± 0.01 mag A(events) 0.15 - 0.22 mag Ds/Dp 0.38 ± 0.02 H 14.0 ± 0.2 (Warner 2005a) Table 1. Summary of results for 5905 Johnson (2008). Lightcurve observations in 2005 obtained by several observers and analyzed by Pravec (Warner et al., 2005a) determined that the Hungaria asteroid, 5905 Johnson, was binary with P 1 = 3.7824 ± 0.0002 h, P orb = 21.7850 ± 0.0005 h, A 1 = 0.11 ± 0.01 mag, and Ds/Dp = 0.40 ± 0.04 (Warner et al., 2005b). Additional analysis of the 2005 data found Ds/Dp = 0.38 ± 0.02. A similar observing campaign was staged by the authors in 2008 to verify and refine the original findings. Observations were obtained from 2008 May through June. During the six-week observing run, the viewing aspect was essentially constant. Several mutual events (occultations or eclipses) were recorded, which affirmed the binary status. As before, analysis of the data was conducted by Pravec. In brief, the analysis involves the dissection of the data into at least two linear, additive Fourier curves due to the rotation of the bodies in the system. Eclipses and Minor Planet Bulletin 36 (2009)
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