================================================================================ IAUC 7552 30dec00 POSSIBLE NOVA IN PUPPIS T. Kato, Kyoto University, reports the discovery by Kazuyoshi Kanatsu (Matsue, Shimane, Japan) on his T-Max 400 film exposures of a new variable star at R.A. = 7h37m58s, Decl. = -25o56'51" (equinox 2000.0). Kanatsu finds no apparent counterpart on the Digital Sky Survey. K. Takamizawa (Saku-machi, Nagano) reports that the new object was not present on 22 T-Max 400 exposures (limiting mag 14) taken by himself between between 1994 Mar. 14 and 1999 Dec. 3; he notes the presence of a close stellar companion of mag 14.5, which is apparently a red star (red mag 13.6) in the USNO A2.0 catalogue having position end figures 58s.43, 46".8. Available magnitudes: 2000 Jan. 15.72 UT, [11.7 (Kanatsu; T-Max 400); Nov. 28.703, 8.6 (Takamizawa; T-Max 400); Dec. 22.578, 8.8 (Takamizawa); 22.731, 8.7 (Kanatsu); 30.585, 8.8 (A. Takao, Kitakyushu, Fukuoka, Japan; unfiltered CCD); 30.612, 9.2 (R. Stubbings, Drouin, Victoria, Australia; visual). ================================================================================ IAUC 7553 31dec00 POSSIBLE NOVA IN PUPPIS T. Kato, Kyoto University, forwards the following additional prediscovery photographic magnitudes for the new variable reported on IAUC 7552, from T-Max 400 film exposures obtained by K. Haseda, Aichi, Japan: Nov. 23.78 UT, 8.8; Dec. 1.77, 8.8. ================================================================================ IAUC 7554 2jan01 POSSIBLE NOVA IN PUPPIS S. Nakano, Sumoto, Japan, reports the following precise position for this variable (cf. IAUC 7552, 7553) by H. Abe (Yatsuka, 0.26-m f/6.0 reflector) from a CCD image taken on Jan. 1.525 UT: R.A. = 7h37m56s.91, Decl. = -25o56'59".7 (equinox 2000.0). G. Masi, Ceccano, Italy, reports the following position end figures from an image taken by M. Uemura (Kyoto University): 56s.91, 59".0. Masi notes the presence of a USNO-A2.0 catalogue star (red mag 13.2) at position end figures 56s.88, 59".1. T. Kato forwards position end figures obtained by K. Kadota (Ageo, Saitama, 0.18-m f/5.5 reflector) from an image taken on Jan. 1.654: 56s.88, 58".9. ================================================================================ IAUC 7556 6jan01 POSSIBLE NOVA IN PUPPIS I. Platais, V. Kozhurina-Platais, and M. I. Zacharias, Universities Space Research Association; and N. Zacharias, U.S. Naval Observatory (USNO), report the following position for this variable star (cf. IAUC 7554) from preliminary reduction of two CCD frames (scale 0".905/pixel) obtained on Jan. 4.227 UT with the USNO 0.20-m f/10 astrograph at Cerro Tololo Interamerican Observatory: R.A. = 7h37m56s.882, Decl. = -25o56'58".88 (equinox 2000.0; 100 Tycho-2 reference stars; estimated standard error 0".05 in each coordinate). The star's red magnitude was measured to be 8.7. There is a star (red mag 13.6; epoch 1999 Mar. 3) in the first USNO CCD Astrographic Catalog (UCAC1) at position end figures 56s.883, 58".88; the same star is also visible (visual mag 13.1) on a pair of the Yale/San Juan Southern Proper Motion program plates taken on 1967 Jan. 18. Preliminary reductions indicate that its absolute proper motion is small: mu(R.A.) cos Decl. = -0".0047/yr and mu(Decl.) = +0".0064/yr (standard error 0".004/yr). R. M. Wagner, LBT Observatory; C. B. Foltz, MMT Observatory; and S. G. Starrfield, Arizona State University write: "A spectrum (range 420-750 nm, resolution 0.35 nm) of the possible nova, obtained on Jan. 4.23 with the 6.5-m MMT (+ blue-channel spectrograph), is dominated by emission lines arising from Fe II (multiplets 27, 37, 38, 42, 46, 48, 49, 55, 73, and 74); Na I 589.4 (1) and 616 (5) nm; and Ca I 658 (1) nm. The emission lines exhibit P-Cyg profiles, and overlapping emission and absorption makes positive spectral identifications difficult. Emission lines arising from H I and He I do not appear to be present. Measurement of several absorption troughs gives a maximum expansion velocity of about 900 km/s. The spectrum is not typical of 'Fe II' classical novae, recurrent novae, or symbiotic novae such as PU Vul or RR Tel." Spectroscopic reports have also been received from several observers using smaller instruments: M. Fujii, Okayama, Japan (0.28-m reflector, 2000 Dec. 31.7 UT); W. Liller, Vina del Mar, Chile (0.20-m Schmidt telescope + objective prism, 2001 Jan. 3.235); and O. Shemmer, E. Leibowitz and J. Dan, Wise Observatory (Jan. 4.00). They all report the prominent emission lines of Fe II; though they also report He I at 587.6 nm, Wagner notes this could also be due to Na I 589.4-nm. Fujii's spectrum (resolution about 1 nm) suggests that H-beta is weak or absent; emission in the other spectra close to H-alpha is likely due to Ca I 658.0-nm, according to Wagner. Shemmer adds that the continuum rises by a factor of 1.5 from 750 to 400 nm, and the spectrum shows emission line widths of Fe II, O I, Na I, and Ca II that correspond to an expansion velocity of about 1000 km/s. ================================================================================ IAUC 7557 6jan01 POSSIBLE NOVA IN PUPPIS CCD photometry of the new variable star noted on IAUC 7552 and 7556 (comparison stars from Tycho catalogue): 2000 Dec. 31.001 UT, V = 9.24 +/- 0.05, B-V = +0.44 +/- 0.07 (D. Hanzl, Brno, Czech Republic); 31.96, V = 9.14 +/- 0.06, B-V = +0.48 +/- 0.06 (Hanzl); 2001 Jan. 1.020, V = 9.13 (M. Lehky, Hradec Kralove, Czech Republic). ================================================================================ IAUC 7559 11jan01 V445 PUPPIS N. N. Samus, Sternberg Astronomical Institute, Moscow, informs us that the designation V445 Pup has been given to the possible nova reported on IAUC 7552 and 7556. N. M. Ashok and D. P. K. Banerjee, Physical Research Laboratory, Ahmedabad, report 1.1-2.3-micron spectroscopy of V445 Pup, with the Mt. Abu 1.2-m telescope (+ PRL Near-Infrared Imaging Spectrometer + HgCdTe NICMOS3 detector array) on Jan. 2.875 UT: "The J- and H-band (1.08-1.78 microns) spectra are dominated by emission features arising from C I, C III, and C IV (the prominent ones being at 1.167, 1.177, 1.259, 1.371, and 1.691 microns). A fairly strong unidentified emission feature is seen at 1.132 microns. The Brackett-series lines of H I in the K and H bands and the Paschen-beta line are not present. However, an emission feature at 1.095 microns, coinciding with the Paschen-gamma line, is likely due to He II. A weak emission line with a P-Cyg profile at 2.062 microns is attributable to He I. A discernible rise in the continuum is seen redward from 1.60 microns, indicating the presence of a cooler component." T. Kato, Kyoto University, reports that a 14-min Tri-X exposure taken by Y. Nakamura (Suzuka, Mie, Japan, 200-mm f/4 camera lens) on 2000 Sept. 26.78 UT shows no object to mag 12.0 at the location of V445 Pup. Photometry by A. C. Gilmore with the 0.6-m f/16 reflector at the University of Canterbury's Mt. John Observatory, Lake Tekapo, New Zealand (reference star Cousins E352; uncertainties about 0.01 mag): Jan. 6.58 UT, V = 9.05, U-B = -0.44, B-V = +0.62, V-R = +0.40, V-I = +1.04. ================================================================================ IAUC 7561 14jan01 V445 PUPPIS W. Liller, Vina del Mar, Chile, writes: "Low-resolution CCD spectra taken on Jan. 6.09, 10.10, and 14.09 UT show a slight weakening of the Fe II lines recorded by me on Jan. 3.23 (IAUC 7556). Otherwise, the four spectra are all very similar. While the lack of hydrogen emission is unusual, other cataclysmic stars such as CR Boo, CP Eri, and V803 Cen are similarly hydrogen- deficient. However, unlike V445 Pup, these stars, are all hot, blue objects showing He lines in emission and never Ca I or Na I." ================================================================================ IAUC 7565 17jan01 V445 PUPPIS W. Liller, Vina del Mar, Chile, reports that inspection of 54 films taken from 1982 Oct. 7 to 1985 Nov. 25 (limiting red-orange mag 10-11) reveals no outburst of V445 Pup. He adds that, observing with a CCD and broadband V filter over a period of 6.5 hr (exposures every 5 min) beginning Jan. 14.115 UT, no detectable variation (rms +/- 0.07 mag) was found in the brightness of V445 Pup (comparison star GSC 6543.2917, located 2'.7 to the south); neither did a period-search program reveal any significant result. G. Masi, Ceccano, Italy, also reports that V445 Pup remained around mag about 8.7 (unfiltered CCD) between Dec. 31.7 and Jan. 7.0, and that short-term fluctuations appeared to be absent. ================================================================================ IAUC 7571 24jan01 V445 PUPPIS R. M. Wagner, LBT Observatory; G. Schwarz, Steward Observatory, and S. G. Starrfield, Arizona State University, report: "Spectra (range 320-960 nm, resolution 0.85 nm) of V445 Pup were obtained on Jan. 19.31 UT with the Bok 2.3-m telescope (+ Boller & Chivens spectrograph) on Kitt Peak. The spectrum has changed little since our previous report (IAUC 7556). In addition to the features present in our earlier spectrum, emission lines of Fe II 325.5- and 327.7-nm; O I 747.7-, 777.4-, 822.7-, 844.6-, 882.0-, and 926.4-nm; Mg I 383.5-, 517.8-, 552.8-, 880.7-, and 892.4-nm; Mg II 789.0-, 823.2-, and 922.6-nm; N I 821.2-, 869.2-, 905.0-, and 939.6-nm; C I 833.5-, 908.8-, and 940.6-nm; and Ca II 393.3-, 396.8-, 849.8-, 854.2-, and 866.2-nm are also present, superposed on a blue continuum. Some of these features exhibit P-Cyg profiles. Hydrogen lines arising from both the Balmer and Paschen series, as well as He II 468.6-nm, are very weak or absent (cf. IAUC 7556, 7559). A weak absorption line at 578.0 nm with an equivalent width of 0.12 nm may be partially interstellar, implying E(B-V) 1500 km/s." Visual magnitude estimates, provided in part by S. Otero, Buenos Aires, Argentina: Jan. 1.026 UT, 9.0 (M. Reszelski, Szamotuly, Poland); 4.243, 9.2 (J. G. de S. Aguiar, Campinas, Brazil); 9.796, 9.7 (A. Pearce, Nedlands, W. Australia); 13.083, 9.0 (P. Schmeer, Bischmisheim, Germany); 16.361, 9.7 (J. Bedient, Honolulu, HI); 18.367, 9.9 (Bedient); 20.028, 9.7 (Otero); 22.083, 9.6 (J. Rodriguez Freitas, Montevideo, Uruguay); 24.067, 9.6 (Otero); 26.047, 9.6 (V. Ladino, Barquisimeto, Venezuela). ================================================================================ IAUC 7580 7feb01 V445 PUPPIS R. W. Russell, D. K. Lynch, and D. Kim, The Aerospace Corporation; and M. L. Sitko and S. M. Brafford, University of Cincinnati, report on infrared spectroscopy of V445 Pup on Jan. 31.45 UT using BASS on the Infrared Telescope Facility: "The spectrum (in radiance units W cm**-2 micron**-1) revealed only a smooth, featureless continuum that decreased monotonically with increasing wavelengths (lambda) between 3 and 13.6 microns. Its slope is much more shallow than the Rayleigh-Jeans tail of a hot blackbody, close to lambda**-1.5. The spectrum is consistent with thermal emission from gray-emissivity dust whose temperatures ranged from about 250 K to upwards of 1000 K. Infrared magnitudes were L = 2.63, M = 1.78, N = -0.16 (all +/- 0.05). The presence of such a strong infrared excess so early in the object's evolution suggests that this object is a recurrent nova and has undergone previous outbursts and dust-formation events." ================================================================================ IAUC 7586 22feb01 V445 PUPPIS Visual magnitude estimates: Jan. 29.386 UT, 9.6 (J. Bedient, Honolulu, Hawaii); Feb. 1.787, 9.8 (A. Pearce, Nedlands, W. Australia); 7.777, 10.1 (Pearce); 14.116, 9.7 (S. Otero, Buenos Aires, Argentina); 18.06, 10.0 (J. Carvajal, Avila, Spain). ================================================================================ IAUC 7602 27mar01 V445 PUPPIS P. Garnavich and J. Quinn, University of Notre Dame, report that time-resolved U-band photometry of this peculiar eruptive variable was obtained with the Vatican Advanced Technology Telescope on Mar. 16, 17, and 19 UT for two hours each night. The average time between consecutive exposures was 60 s. Contrary to the quiescence noted in January (IAUC 7565), the object showed significant variability in the ultraviolet. The star brightened at a rate of 0.16 mag/day over the observing run and showed 10-percent variations on individual nights. No periodicity is evident in the light curve. An additional set of images obtained at the Fred L. Whipple Observatory by J. Graves and P. Berlind on Mar. 26.1 shows the ultraviolet magnitude back to its Mar. 17 level of U = 10.2. Further monitoring at all wavelengths is encouraged. Visual magnitude estimates: Feb. 20.403 UT, 9.8 (J. Bedient, Honolulu, HI); 27.559, 10.2 (A. Pearce, Nedlands, W. Australia); Mar. 6.783, 10.3 (M. Lehky, Hradec Kralove, Czech Republic); 14.361, 9.6 (M. Linnolt, Honolulu, HI); 19.271, 9.9 (Bedient). ================================================================================ IAUC 7620 5may01 V445 PUPPIS A. C. Gilmore and P. M. Kilmartin report photometry obtained with the 0.6-m f/16 Cassegrain telescope at the Mt. John Observatory, indicating that this novalike variable is fading after varying around mag 10 for the past two months: Apr. 12.41 UT, V = 9.80, U-B = -0.40, B-V = +0.56, V-R = +0.46, V-I = +1.03; 13.36, 9.97, -0.39, +0.56, +0.47, +1.05; 14.37, 10.13, -0.39, +0.55, +0.50, +1.07; 16.38, 10.21, -0.39, +0.54, +0.50, +1.04; 18.50, 10.33, -0.40, +0.53, +0.53, +1.09; 21.41, 10.64, -0.33, +0.56, +0.54, +1.13; 22.40, 10.61, -0.26, +0.59, +0.56, +1.17; 23.45, 10.74, -0.26, +0.62, +0.60, +1.22; 24.35, 10.86, -0.32, +0.60, +0.62, +1.27; 26.33, 11.04, -0.14, +0.62, +0.63, +1.29. The uncertainties are generally < 0.02 mag (but Apr. 24 observations affected by cloud). ================================================================================ IAUC 7717 13sep01 V445 PUPPIS M. P. Rupen, V. Dhawan, and A. Mioduszewski, National Radio Astronomy Observatory, report: "Observations with the Very Large Array (VLA) at 8.46 GHz on Sept. 9 show a 9.6-mJy point source (rms 0.095 mJy/beam) at R.A. = 7h37m56s.87, Decl. = -25o56'58".9 (equinox 2000.0; uncertainty 0".1-0".2 in each coordinate). This agrees with the optical position of V445 Pup (IAUC 7556). Observations at the same frequency on Jan. 18 gave no detection (rms 0.095 mJy/beam). VLA data taken on Sept. 11 and 12 confirm the detection and show a slowly decaying source (exponential timescale of 25 +/- 3 days) with a power-law spectrum (flux density proportional to nu**-0.7, where nu is the frequency) between 5 and 15 GHz. The 1.425-GHz flux density, however, is lower than a simple extrapolation would suggest, giving an inferred foreground opacity of 0.4 at that frequency. If this is correct, either the source is small enough (milliarcsec) for synchrotron self-absorption, or there is a great deal of ionized gas providing free-free absorption along the line-of-sight. The radio emission probably comes either from a recent energetic event, or from the development of a shock associated with the Dec. 2000 outburst. Observations at optical, infrared, and x-ray wavelengths would be very useful in tracing the origin of the radio emission." R. M. Wagner, LBT Observatory; G. Schwarz, Steward Observatory; S. G. Starrfield, Arizona State University; and C. B. Foltz, MMT Observatory, write: "Spectra (range 400-950 nm, resolution 0.85 nm) of V445 Pup, obtained on Apr. 15-16 UT (just prior to conjunction with the sun) using the Bok 2.3-m telescope on Kitt Peak, show strengthening emission lines of carbon compared to our previous reports (cf. IAUC 7556, 7571). The emission lines include C I (multiplets 3, 9-10) and C II (multiplets 1-3, 5-6, 14-16, 19-20), as well as features arising from Fe II, O I, Mg I, Mg II, N I, Ca I, Ca II, and perhaps Na I (described previously). Emission lines arising from He I (587.5, 667.8, 706.5, and 728.1 nm) are also present (cf. IAUC 7556). The equivalent width of the C II line at 658 nm was 4.6 nm. A spectrum (range 390-540 nm, resolution 0.14 nm) obtained on Mar. 29 by S. Howell and P. Szkody with the 6.5-m MMT shows that many of these features exhibit P-Cyg profiles in which the absorption components are relatively sharp (FWHM 130 km/s; terminal velocity -600 km/s), while the emission components exhibit considerable structure and long red tails extending to about +3800 km/s, suggesting an asymmetric outburst. A broad and weak emission feature (equivalent width 0.32 nm) at 486.1 nm might be H-beta. Additional spectroscopic observations are urgently requested." ================================================================================ IAUC 7728 5oct01 V445 PUPPIS M. P. Rupen, A. J. Mioduszewski, and V. Dhawan, National Radio Astronomy Observatory, write: "Observations with the Very Large Array show that V445 Pup is currently undergoing a renewed, strong radio flare. Data taken on Oct. 4 give flux densities of 11.72 +/- 0.23, 14.20 +/- 0.10, and 12.17 +/- 0.08 mJy at 1.425, 4.860, and 8.460 GHz, respectively. The 4.86- and 8.46-GHz flux densities are significantly higher than those measured on Sept. 25 (8.3 +/- 0.1 and 7.1 +/- 0.1 mJy, respectively). The 1.425-GHz measurement is much lower than a simple extrapolation of the high-frequency data would suggest, implying substantial absorption. The opacity inferred from earlier radio spectra was much lower, so we are probably seeing synchrotron self-absorption in a small (on the order of milliarcseconds) radio source that becomes optically thin as it expands. Further observations at other wavelengths are strongly encouraged." ================================================================================ IAUC 7730 9oct01 V445 PUPPIS A. A. Henden, Universities Space Research Association and U.S. Naval Observatory, Flagstaff Station (USNOFS); R. M. Wagner, LBT Observatory; and S. G. Starrfield, Arizona State University, report that the following infrared photometry of V445 Pup was obtained in the pre-dawn sky with the USNOFS 1.55-m telescope(+ ASTROCAM): Sept. 29.61 UT, L' = 5.74 +/- 0.12 (cf. L = 2.63 +/- 0.05 on Jan. 31.5; IAUC 7580); Oct. 4.54, K' = 9.15 +/- 0.02. However, V- and I-band CCD images obtained at large airmass in a brightening sky with the USNOFS 1.0-m telescope on Oct. 4.51 show no object brighter than V = 20 and I = 19.5 mag at the location of V445 Pup. Henden et al. remark: "The object is evidently shrouded in a thick and dense carbon dust shell, in view of the apparent over-abundance of carbon in the ejecta previously observed in infrared and optical spectra (cf. IAUC 7559 and 7717). Further observations are requested to follow the evolution of this unique object." ================================================================================ IAUC 7955 17aug02 V445 PUPPIS P. A. Woudt, University of Cape Town, reports the following simultaneous J, H, and K_s photometry of V445 Pup, obtained at the South African Astronomical Observatory, Sutherland, with the 1.4-m IRSF telescope (+ SIRIUS): Mar. 22.763 UT, H = 17.63 +/- 0.06, K_s = 14.07 +/- 0.02; June 19.689, H = 18.09 +/- 0.12, K_s = 15.29 +/- 0.03. V445 Pup was below the detection limit (mag 19.5) in J at both epochs. Woudt adds: "The H-K_s color has changed significantly over this period, from +3.56 +/- 0.06 to +2.80 +/- 0.12, and V445 Pup has become fainter in both photometric passbands. One and a half years after outburst, V445 Pup is still shrouded in a dense dust shell (see IAUC 7730)." ================================================================================ IAUC 8642 9dec05 V445 PUPPIS D. K. Lynch, R. J. Rudy, C. C. Venturini, and S. Mazuk, Aerospace Corporation; R. C. Puetter, University of California at San Diego; R. B. Perry, Langley Research Center, NASA; and B. Walp, Lick Observatory, report 1.0- to 2.5-micron spectroscopy of V445 Pup (cf. IAUC 7559, 7580) with the Lick 3.0-m telescope (+ VNIRIS) at Nov. 16.535 UT. The object has faded and the thermal dust emission (Lynch et al. 2004, A.J. 128, 2962) has virtually disappeared. No visible counterpart has appeared, so it is likely that the dust has cooled significantly. Structured He I emission at 1.0830 microns remains strong. ================================================================================ ================================================================================