T Pyx

1. T Pyx Patterson et al. (1998) IM Nor In tail of eruption (Woudt & Warner 2003) COMPREHENSIVE PHOTOMETRIC HISTORIES OF ALL KNOWN GALACTIC RECURRENT NOVAE Bradley E. Schaefer (Louisiana State University) OVERVIEW: I collect virtually all photometry of the ten known galactic recurrent novae (RNe) and their 37 known eruptions. This consists of my modern measures of nearly all archival plates (providing the only data for half of 37 known eruptions), my own 10,000 CCD magnitudes from 1987 to present (providing virtually all of the magnitudes in quiescence for seven RNe), over 140,000 visual magnitude estimates recorded by amateur astronomers (who discovered half the known eruptions), and the small scattering of magnitudes from all the literature. From this, I produce various uniform products; (1) BVRIJHK comparison star magnitudes and BV comparison star sequences to cover the entire range of eruption, (2) complete light curves for all eruptions, (3) best fit B and V light curve templates, (4) orbital periods for all-but-one RN, (5) exhaustive searches for all missed eruptions, (6) measured discovery efficiencies since 1890, (7) true recurrence time scales, (8) predicted next eruption dates, (9) variations on time scales of minutes, hours, days, months, years, decades, and century, (10) uniform distances and extinctions to all RNe, (11) BV colors at peak and UBVRIJHK colors at minimum all with extinction corrections, and (12) the spectral energy distributions over UBVRIJHK. Highlights of this work include the discoveries of one new RN, six previously-undiscovered eruptions, and the discovery of the orbital periods for half the RNe. The goal of this work is to provide uniform demographics for answering questions like `What is the death rate of RNe in our galaxy?' and `Are the white dwarfs gaining or losing mass over each eruption cycle?'. An important use of this work is for the question of whether RNe can be the progenitors of Type Ia supernovae. HIGHLIGHTS: DISCOVERIES: One New Recurrent Nova -- V2487 Oph with eruptions in 1900 and 1998 Five Orbital Periods -- V745 Sco with Porb=510±20, V3890 Sgr with Porb=519.7±0.3, V394 CrA with Porb=1.515682±0.000008, U Sco with Porb=1.2305631±0.0000030, T Pyx with Porb=0.07616±0.00017 Six Previously-Undiscovered Eruptions -- U Sco in 1917, 1945, 1969; RS Oph in 1907; V2487 Oph in 1900; CI Aql in 1941 Sharp Drops in Eruption Light Curves -- U Sco at 33 days; T Pyx at 85 days RESULTS: U Sco will Erupt Any Month Now -- Join our large collaboration of observers now prepared for intensive study of the upcoming eruption! Four other RNe will erupt in next decade -- Intensive monitoring needed for V2487 Oph, V394 CrA, V745 Sco, and V3890 Sgr RS Oph Red Giant is Filling its Roche Lobe Five Reliable Distances based on Companion Star -- U Sco at 12000±2000 pc, T CrB at 800±140 pc, RS Oph at 4300±700 pc, V745 Sco at 7300±1200 pc, V3890 Sgr at 6000±1000 pc Horrifyingly Low Discovery Efficiencies -- 4% median efficiency for undirected searches (0.6% to 19% full range); 60% median efficiency for directed searches (30% to 100% full range). This means that ~80 so-called “classical novae” currently (out of the ~300 novae now in catalogs) are really RNe with undiscovered nova events in the last century. COMPLETE LIGHT CURVES FOR ALL ERUPTIONS - Plus Templates (on modern magnitude scale) LIGHT CURVES DURING QUIESCENCE T CrB Zamanov et al. (2004)