Scoperta Supernova in NGC 5806

Scoperta un altra supernova dal team ISSP Italian Supernovae Search Project, questa volta è stato Fabio Briganti, responsabile della ricerca supernovae presso l’osservatorio astronomico di Montecatini val di Cecina Pisa.

L’immagine è stata effettuata con il telescopio da 28cm C11 celestron presso l’osservatorio di Cortina la mattina del 22 gennaio.

Controllo da parte di Fabio Briganti, immagine ottenuta tramite controllo robotizzato da Alessandro Dimai.

Complimenti al nostro coordinatore per la ricerca SN.

Montecatini astronomical centre redazione.

PSN J14595904+0153251 (A.R. 14 59 59.04, Dec. +01 53 25.1) scoperta il 22 gennaio 2012 nella galassia NGC5806 (offset 10W 1S), magnitudine 15.0.

PSN scoperta da F. Briganti con il telescopio Schmidt Cassegrain da 11″ dell’Osservatorio del Col Drusciè (Cortina d’Ampezzo).

Un ulteriore immagine dellaSN in NGC 5806 ripresa la mattina del 26 gennaio dall’osservatorio astronomico di Montecatini val di Cecina con telescopio meade 35cm e camera SBIG STXME KAF1600

Atel inerenti alle osservazioni della Supernova.

The PTF (ATEL #1964, #3253; http://www.astro.caltech.edu/ptf ) reports the discovery of a new supernova in NGC 5806 (independently discovered by F. Briganti and reported as PSN J14595904+0153251 on Jan 22). The source is located at RA = 14:59:59.08, Dec = +01:53:24.2 (J2000), was first detected by the Palomar 1.2m telescope with an R-band magnitude of about 17 on 2012 Jan 10 (UT) and brightened to about 16.1 mag on Jan 20. PTF did not detect the source prior to 2012 Jan 5. Spectroscopic follow-up was performed with the HET (+LRS) on Jan 14, the INT (+IDS) on Jan 15-18, Gemini N (+GMOS) on Jan 17 and the Palomar 5m (+DBSP) on Jan 18. The spectra show prominent H features as well as He absorption at about 10,000 km/s, consistent with a type IIb classification.

Credential Certification: Christopher J. Stockdale (chris.stockdale@mu.edu)

Subjects: Radio, X-ray, Supernovae

We report the detection of radio emission near the position of the type-IIb supernova PTF2012os (ATEL #3881) with the Karl G. Jansky Very Large Array radio telescope in the DnC configuration: A flux density of 0.44 +/- 0.05 mJy was measured at 5.02 GHz (wavelength 6.0 cm) on 2012 Jan. 22.42 UT. The measured position of the radio emission of R.A. = 14h59m59.s12, Decl. = +01d53m23s.3, equinox 2000.0 is in good agreement with the measured optical position of (ending digits) R.A. = 59.s08, Decl. = 24s.2, equinox 2000.0 (ATEL #3881). Radio observations are continuing. Using 9.4 ks of co-added Swift X-Ray Telescope (XRT) data, obtained on 2012-01-14 (2.0 ks exposure time; PI Kasliwal), 2012-01-16 (2.4 ks; PI Kasliwal), and 2012-01-24 (5.0 ks; PI Immler), no X-ray source is detected at the position of the SN. The PSF, dead-time, and vignetting corrected upper limit to the XRT net count rate is 1.1E-03 cts/s (3-sigma), corresponding to an unabsorbed (0.2-10 keV band) X-ray flux limit of 5.4E-14 erg/cm/cm/s and a luminosity limit of 4.2E39 erg/s for an adopted thermal plasma spectrum with a temperature of kT = 10 keV, a Galactic foreground column density of 4.14E+20 (Dickey & Lockman, 1990, ARAA 28) and a distance of 25.4 Mpc (NED). Swift observations are continuing. The object warrants further study in all wavelength bands.

Credential Certification: Schuyler D. Van Dyk (vandyk@ipac.caltech.edu)

Subjects: Optical, Supernovae, Transient, Variables

Schuyler D. Van Dyk (Spitzer Science Center/Caltech), Avishay Gal-Yam, Iair Arcavi (Weizmann Institute), Mansi M. Kasliwal (OCIW/Princeton), and Assaf Horesh (Caltech), on behalf of the larger PTF collaboration, report their attempt to identify the progenitor of the Type IIb supernova PTF12os, aka PSN J14595904+0153251, in archival Hubble Space Telescope (HST) ACS/WFC F435W, F555W, and F814W images from 2005 March 10 UT (PI: Smartt). We have astrometrically matched a B-band image (with 0.87″ seeing) from 2012 January 18 UT obtained with the IMACS camera on the Magellan Baade 6.5 m telescope at Las Campanas Observatory, Chile, with the ACS F435W image, using 10 fiducial stars in common. The SN position has been located on the ACS image with an uncertainty of 0.57 WFC pixel, or 0.028″. This is within 1 WFC pixel, to the southwest, of a candidate source detected in all three ACS bands. The site of PTF12os lies approximately 2.2″ southeast of the position of the Type II SN 2004dg in this same host galaxy. Preliminary photometry of the ACS images using Dolphot (Dolphin 2000, PASP, 112, 1383) results in a brightness for the object of B=23.30, V=23.04, and I=22.53 (uncertainties are all 0.012 mag or smaller). Assuming the average value of the distance modulus to the host, NGC 5608, from the NASA/IPAC Extragalactic Database (NED), 32.01 mag, and also assuming only the Galactic foreground extinction at V-band from Schlegel, Finkbeiner, & Davis (1998, ApJ, 500, 525), 0.17 mag, this object had V absolute magnitude of -9.1 and absolute colors (B-V)_0=0.21 and (V-I)_0=0.44 (consistent with an early F spectral type). This could be a highly-luminous supergiant star, or, alternatively, a compact star cluster. Evidence exists from the strength of the Na I D lines in follow-up spectra (ATel 3881) that the extinction to the SN could, in fact, be higher, implying that the source is even more luminous and bluer. We tentatively identify this source as a candidate for the progenitor, although given the offset of the SN position from the object’s centroid, the host galaxy distance, and the inferred higher extinction, it is quite possible that the progenitor has not been detected. Higher-resolution imaging is pending for candidate confirmation, and further analysis is ongoing.

Credential Certification: Assaf Horesh (assafh@astro.caltech.edu)

Subjects: Millimeter, Supernovae

We report a CARMA observation of the type IIb supernova PTF12os (Arcavi et al.; ATEL# 3881). The observation was undertaken on 2012 Jan 14.65 UT. We report a null-detection in the 3-mm band (at a center frequency of 93 GHz) with a 3 sigma upper limit of 0.36 mJy/beam. We thank the CARMA staff for scheduling this target of opportunity.

Pubblicazione della scoperta.

Central Bureau for Astronomical Telegrams INTERNATIONAL ASTRONOMICAL UNION CBAT Director:  Daniel W. E. Green; Hoffman Lab 209; Harvard University;  20 Oxford St.; Cambridge, MA  02138; U.S.A. e-mail:  cbatiau@eps.harvard.edu (alternate  cbat@iau.org) URL http://www.cbat.eps.harvard.edu/index.html Prepared using the Tamkin Foundation Computer Network

SUPERNOVA 2012P IN NGC 5806 = PSN J14595904+0153251      Alessandro Dimai, Cortina d’Ampezzo, Italy, on behalf of the Italian Supernovae Search Project (ISSP), reports the discovery by Fabio Briganti (Santa Croce sull’Arno, Pisa, Italy) of an apparent supernova (mag about 15.0) on unfiltered CCD images (limiting mag about 16.5) taken with the “Maioni” 0.28-m telescope of the Osservatorio Astronomico del Col Druscie at Cortina d’Ampezzo, Italy, on Jan. 22.1556 UT.  The new object is located at R.A. = 14h59m59s.12, Decl. = +1d53’24″.4 (equinox 2000.0), which is 10″ west and 1″ south of the nucleus of NGC 5806.  Nothing is visible at this position on Palomar Sky Survey infrared, red, and blue plates.  The discovery image is posted at website URL http://tinyurl.com/7lzoeyv.  The variable was designated PSN J14595904+0153251 when it was posted at the Central Bureau’s TOCP webpage and is here designated SN 2012P based on the spectroscopic confirmation reported below.  Additional CCD magnitudes for 2012P (unfiltered unless noted otherwise):  2011 Dec. 7, [18.0 (ISSP); 2012 Jan. 23.227, 15.2 (Briganti); 23.549, 16.3 (Joseph Brimacombe, Cairns, Australia; remotely using a 51-cm RCOS telescope + STL11K camera + luminance filter at the New Mexico Skies Observatory near Mayhill, NM, U.S.A.; position end figures 59s.09, 24″.1; image posted at URL http://www.flickr.com/photos/43846774@N02/6752536997/). The type-II supernova 2004dg also appeared in NGC 5806 (cf. IAUC 8375).

L. Borsato and V. Nascimbeni, Dipartimento di Fisica e Astronomia, Universita di Padova; and S. Benetti, A. Pastorello, S. Valenti, L. Tomasella, E. Cappellaro, P. Ochner, and M. Turatto, Osservatorio Astronomico di Padova, Istituto Nazionale di Astrofisica, report that a spectrum (range 360-810 nm; resolution 2.2 nm) of PSN J14595904+0153251 = SN 2012P was obtained on Jan. 23.17 UT with the Ekar-Copernico 1.82-m telescope (+ AFOSC).  Using a library of supernova spectra via GELATO (Harutyunyan et al. 2008, A.Ap. 488, 383; available via https://gelato.tng.iac.es/login.cgi), they found a best match with typical type-Ib/c supernovae soon after maximum if a redshift of z = 0.004533 (Falco et al. 1999, PASP 111, 438; via NED) is assumed.  From the minimum of a deep-intense absorption measured at 627.6 nm, an expansion velocity of about 5100 km/s is deduced for the ejecta if identified with Si II 635.5-nm (but an expansion velocity of about 14400 km/s if identified with H-alpha).

NOTE: These ‘Central Bureau Electronic Telegrams’ are sometimes       superseded by text appearing later in the printed IAU Circulars.

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