From jop at astro.columbia.edu Tue Aug 2 21:02:29 2011 From: jop at astro.columbia.edu (Joe Patterson) Date: Tue, 02 Aug 2011 21:02:29 -0400 Subject: (cba:news) SV Ari bright? Message-ID: <4E389E25.90807@astro.columbia.edu> Dear CBAers, This object is *way* out of season - but it's likely to be a very important star, as a very rare outburster. If we can blend together a few time-series (the longer the better)from separate longitudes, the rewards might be considerable! joe -------- Original Message -------- Subject: [vsnet-alert 13538] Re: SV Ari bright? Date: Wed, 03 Aug 2011 02:47:39 +0200 From: Gianluca Masi To: Ohshima CC: vsnet-alert at ooruri.kusastro.kyoto-u.ac.jp, vsnet-outburst at ooruri.kusastro.kyoto-u.ac.jp, vsnet-outburst at yahoogroups.com, variable_star_forum at yahoogroups.com, vsnet-campaign-dn at ooruri.kusastro.kyoto-u.ac.jp, vsnet-alert at yahoogroups.com, vsnet-campaogn-nova at kusastro.kyoto-u.ac.jp Dear All, I confirm the presence of a 15-mag source there. The object is just rising here in Italy, will try to cover it for a while. regards, Gianluca Masi Ohshima ha scritto: > SV Ari bright? > > According to R. Stubbings, SV Ari (N: in GCVS) is bright. > This object is suspected to be a WZ Sge type dwarf nova. > >> An observation on SV Ari this morning shows the star at mag. 15.0. Observed >> the field for an hour before haze covered the sky. Can someone check this >> out. >> >> ARISV 110802.788 150 Stu.RASNZ > > From jop at astro.columbia.edu Fri Aug 5 05:53:29 2011 From: jop at astro.columbia.edu (Joe Patterson) Date: Fri, 05 Aug 2011 05:53:29 -0400 Subject: (cba:news) sv ari and xss0056+4548 Message-ID: <4E3BBD99.9020307@astro.columbia.edu> Dear CBAers, Looks like SV Ari will pan out, especially if European observations can continue for a few more days (to solve the alias problems in period-finding). Since you're doing so well with such an awkward sky position, here's a much easier one (for us borealites); XSS J00564+4548. We left that one in January; now it's time to make friends with it in the morning sky, in order to solve the yearly-alias problems. It has a complex spectrum of periodic signals - definitely in the "observe early and often" category. Plus, I hear that our old friends V1223 Sgr and V455 And are BEGGING for time-series coverage. joe From jop at astro.columbia.edu Fri Aug 19 05:17:46 2011 From: jop at astro.columbia.edu (Joe Patterson) Date: Fri, 19 Aug 2011 05:17:46 -0400 Subject: (cba:news) New transient in Andromeda Message-ID: <4E4E2A3A.4030001@astro.columbia.edu> Dear CBAers, This looks like a very interesting candidate for study, and pretty well-placed. Unless it's a flat-liner, worth extensive study! joe ATEL #3570 Subjects:Optical, Transient The MASTER auto-detection system at Kislovodsk detected a new transient source at the position (R.A., Dec) 23h 20m 22.36s , +44d 43m 30s.8 , (J2000) with a typical uncertainty of 0.5" at 2011-08-17 23:10:15.502 (UT). The OT also was seen at images after ~45 min (2011-08-17 23:10:15 UT). The unfiltered magnitude is about 15.9 +- 0.1 ( exptime 180s, mlim = 18.0). There is no minor planet or any object brighter 21 mag in DSS at this place. We have a number images this field without OT with limit up to 19.0m. The discovery and references images available here http://master.sai.msu.ru/static/OT/OT232022+444330.png Spectral observations are needed. From jop at astro.columbia.edu Sat Aug 20 14:21:09 2011 From: jop at astro.columbia.edu (Joe Patterson) Date: Sat, 20 Aug 2011 14:21:09 -0400 Subject: (cba:news) August stars Message-ID: <4E4FFB15.7040906@astro.columbia.edu> An embedded and charset-unspecified text was scrubbed... Name: cba82011 URL: From jop at astro.columbia.edu Wed Aug 31 09:11:13 2011 From: jop at astro.columbia.edu (Joe Patterson) Date: Wed, 31 Aug 2011 09:11:13 -0400 Subject: (cba:news) A new X-ray transient, optically identified In-Reply-To: <20110831015903.F0D3616F92A2@sedna.astro.columbia.edu> References: <20110831015903.F0D3616F92A2@sedna.astro.columbia.edu> Message-ID: <4E5E32F1.3020300@astro.columbia.edu> Dear CBAers, Here's the precise position for a new X-ray transient. Many of these stars are CV analogues with neutron-star or black-hole accretors. And significantly for us, often flash short-period modulations of the sort we're familiar with: orbital signals, superhumps, QPOs, etc. And 16th magnitude for now - within our ken. Not the greatest of sky positions, but fire away with all available glass - and with a range of longitudes, we'll figure it out! joe ------------------------------------------------------------------------------ ------------------------------------------------------------------------------ The Astronomer's Telegram http://www.astronomerstelegram.org ============================================================================== ATEL #3613 ATEL #3613 Title: MAXI J1836-194: Swift localization and optical counterpart Author: J. A. Kennea, E. A. Hoversten, M. H. Siegel (PSU), P. A. Evans (U Leicester), H. A. Krimm (CRESST/GSFC/USRA), P. Romano, V. Mangano (INAF-IASFPA), P. Curran (CEA-Saclay), K. Yamaoka (AGU) and H. Negoro (Nihon U.) Queries: kennea at swift.psu.edu Posted: 31 Aug 2011; 02:01 UT Subjects:Optical, X-ray, Transient At 16:46 UT on August 30th, 2011 Swift began a 1ks target of opportunity observation of the newly discovered X-ray transient MAXI J1836-194 (Negoro et al., ATEL #3611). Analysis of Swift/XRT Photon Counting mode data reveal a bright (~36 XRT count/s), uncatalogued X-ray source at the following UVOT enhanced location: RA/Dec (J2000) = 278.93097, -19.32004, which is equivalent to: RA(J2000) = 18h 35m 43.43s Dec(J2000) = -19d 19m 12.1s with an estimated uncertainty of 1.8 arc-seconds radius (90% confidence). This position lies 12 arcminutes from the center of the 0.2 degree MAXI error circle, consistent with that position, and 4.2 arc-minutes from the BAT position, 1.2 arc-minutes outside the BAT 90% confidence error circle. However, given the brightness of this source and the fact that it matches no catalogued X-ray source, we conclude that the XRT detected source is MAXI J1836-194. The spectrum can be described by an absorbed power-law model with photon index 2.34 +/- 0.15, and N_H = 2.0 +/- 0.4 x 10²¹ cm^-2, which is consistent with the expected Galactic value of 2.23 x 10²¹ cm^-2 in that direction (Kalberla et al., 2005). The source flux is 1.1 +/- 0.1 x 10^-9 erg/s/cm² (0.3-10 keV, uncorrected for absorption). The corrected flux is ~2 x 10^-9 erg/s/cm², which if we assume a distance of 8.5 kpc, equates to a luminosity of ~10³⁶ erg/s (0.3 - 10 keV). The brightness is consistent with a constant level during the 1ks observation. Analysis of UVOT data finds a V=16.20 +/- 0.04, U= 16.36 +/- 0.04 counterpart which does not appear in the to be present in the DSS or 2MASS archival images of the field. The refined UVOT position is RA/Dec (J2000) = 278.93104, -19.31967, equivalent to: RA(J2000) = 18h 35m 43.45s Dec(J2000) = -19d 19m 10.8s with an estimated uncertainty of 0.5 arc-seconds (radius, 90% confidence, statistical + systematic). This position lies 1.35 arc-seconds from the center of the UVOT enhanced XRT position, inside the 90% confidence error circle. This source is not consistent with the position of any catalogued optical source, and therefore we suggest that this is the optical counterpart of MAXI J1836-194. Multi-wavelength follow-up observations to determine the nature of this source are encouraged. This work made use of data supplied by the UK Swift Science Data Centre at the University of Leicester (Evans et al. 2009, MNRAS, 397, 1177). ------------------------------------------------------------------------------ Password Certification: Jamie A. Kennea (kennea at astro.psu.edu) http://www.astronomerstelegram.org/?read=3613 ============================================================================== ============================================================================== This is an automatically-generated notice. 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