SUPERHUMPS IN CATACLYSMIC BINARIES. XXI. HP LIBRAE (= EC 15330–1403) JOSEPH PATTERSON, 1 ROBERT A. FRIED, 2 ROBERT REA, 3 JONATHAN KEMP, 1,4,5 CATHERINE ESPAILLAT, 1 DAVID R. SKILLMAN, 6 DAVID A. HARVEY, 7 DARRAGH O’DONOGHUE, 8 JENNIE MCCORMICK, 9 FRED VELTHUIS, 9 STAN WALKER, 10 ALON RETTER, 11,12 YIFTAH LIPKIN, 11 NEIL BUTTERWORTH, 13 PADDY MCGEE, 14 AND LEWIS M. COOK 15 submitted • Publications of the Astronomical Society of the Pacific • 2001 August 14 2001 August 14 Revision 1 Department of Astronomy, Columbia University, 550 West 120th Street, New York, NY 10027; jop@astro.columbia.edu, cce10@columbia.edu 2 Braeside Observatory, Post Office Box 906, Flagstaff, AZ 86002; captain@braeside.org 3 Center for Backyard Astrophysics (Nelson), Regent Lane Observatory, 8 Regent Lane, Richmond, Nelson, New Zealand; reamarsh@ihug.co.nz 4 Joint Astronomy Centre, University Park, 660 North A`ohōkū Place, Hilo, HI 96720; j.kemp@jach.hawaii.edu 5 Visiting Astronomer, Cerro Tololo Interamerican Observatory, National Optical Astronomy Observatories, which is operated by the Association of Universities for Research in Astronomy, Inc. (AURA) under cooperative agreement with the National Science Foundation 6 Center for Backyard Astrophysics (East), 9517 Washington Avenue, Laurel, MD 20723; dskillman@home.com 7 Center for Backyard Astrophysics (West), 1552 West Chapala Drive, Tucson, AZ 85704; dharvey@comsoft-telescope.com 8 South African Astronomical Observatory, Post Office Box 9, Observatory 7935, Cape Town, South Africa; dod@saao.ac.za 9 Center for Backyard Astrophysics (Pakuranga), Farm Cove Observatory, 2/24 Rapallo Place, Farm Cove, Pakuranga, Auckland, New Zealand; fco@xtra.co.nz 10 Center for Backyard Astrophysics (Waiharara), Wharemaru Observatory, Post Office Box 13, Awanui 0552, New Zealand; astroman@voyager.co.nz 11 Wise Observatory and Department of Astronomy, Tel Aviv University, Ramat Aviv, Tel Aviv 69978, Israel; yiftah@wise.tau.ac.il 12 Currently at: Astrophysics Group, Department of Physics, Keele University, Keele, Staffordshire, ST5 5BG, England, United Kingdom; ar@astro.keele.ac.uk 13 Center for Backyard Astrophysics (Townsville), 24 Payne Street, Mt. Louisa, Queensland 4814, Australia; neilbutt@bigpond.com.au 14 University of Adelaide, Department of Physics and Mathematics, Adelaide 5005, Australia; pmcgee@physics.adelaide.edu.au 15 Center for Backyard Astrophysics (Concord), 1730 Helix Court, Concord, CA 94518; lcoo@yahoo.com