Possible Supernova in M61 (NGC 4303)

Following the posting on the Central Bureau's Transient Object Confirmation Page about a possible Supernova in the barred spiral galaxy Messier 61 (or NGC 4303 - TOCP Designation: PSN J12215757+0428185) we performed some follow-up of this object through a 0.10-m f/5.0 astrograph + CCD from MPC Code H06 (iTelescope, New Mexico). 

On our images taken on October 30.5, 2014 we can confirm the presence of an optical counterpart with unfiltered CCD magnitude 13.2 and at coordinates:

R.A. = 12 21 57.61, Decl.= +04 28 17.8

(equinox 2000.0; UCAC-3 catalogue reference stars).
 

 Our confirmation image (click on it for a bigger version)

An animation showing a comparison between our confirmation image and the archive POSS2/UKSTU plate (IR Filter - 1991). Click on the thumbnail below for a bigger version:

UPDATE - October 31, 2014

ATel #6648 issued on 31 Oct 2014 confirms PSN J12215757+0428185 as a Type Ia-pec Supernova. Spectroscopic classification has been obtained by "The Asiago Transient Classification Program" with the Asiago 1.82 m Copernico Telescope (+AFOSC; range 340-1000 nm; resolution 1.2 nm) and 1.22 m Galileo Telescope (+Boller&Chivens; range 360-790 nm; resolution 0.8 nm). According to the Asiago team: "Heliocentric radial velocity of the host galaxy M61 from Bingelli et al. 1985, AJ 90, 1681 via NED. Distance modulus (Virgo + GA + Shapley) m-M = 30.67[0.15] mag, suggesting an absolute mag M~-17.4. The spectrum shows a blue continuum with relatively weak and narrow Si II 635.5-nm absorption. Fe III lines at 430 and 500 nm are visible, suggesting that the object might be a member of the Type-Iax class of supernovae". Click on the image below to see a bigger version of spectrum obtained at Asiago.

Credit: The Asiago Transient Classification Program

This SN will have an official designation as soon as CBAT will issue its circular. Including this one, the total number of supernovae observed in M61 arrives to 7.

UPDATE - November 01, 2014

Cbet 4011 with the official designation for the SN in M61 has been issued: SUPERNOVA 2014dt IN M61 = PSN J12215757+0428185. Below you can see our confirmation image updated with official designation in the caption. Click on it for a bigger version. 

by Ernesto Guido, Martino Nicolini & Nick Howes

Possible Supernova 2014L in M99 galaxy

Following the posting on the Central Bureau's Transient Object Confirmation Page about a possible Supernova in M99 spiral galaxy (TOCP Designation: PSN J12184868+1424435) we performed some follow-up of this object through a 0.50-m f/6.8 astrograph + CCD + f/4.5 focal reducer from MPC Code H06 (iTelescope, New Mexico).

On our images taken on January 28.4, 2014 we can confirm the presence of an optical counterpart with unfiltered CCD magnitude 15.7 and at coordinates:

R.A. = 12 18 48.73, Decl.= +14 24 44.3

(equinox 2000.0; UCAC-3 catalogue reference stars).

Our confirmation image (click on it for a bigger version)

An animation showing a comparison between our confirmation image of this transient in M99 and archive image by 2-meter telescope FTN - LCOGT (dated back to April 18, 2013). Click on the thumbnail below for a bigger version:

Before the discovery of this transient,  three supernovae were observed in M99: 1967H (type II), 1972Q (type IIP)and 1986I (type IIP).

UPDATE - January 30, 2014

According to Cbet 3795 issued on January 30, PSN J12184868+1424435 is a type-Ic supernova with official designation 2014L. The supernova has been discovered on unfiltered CCD images taken on Jan. 26.83 UT using the 0.6-m NAOC Schmidt telescope in the course of the THU-NAOC Transient Survey (TNTS). 

by Ernesto Guido, Nick Howes & Martino Nicolini

SN 2014J - Bright Supernova in M82

Following the posting on the Central Bureau's Transient Object Confirmation Page about a possible Supernova in M82 (TOCP Designation: PSN J09554214+6940260) we performed some follow-up of this object through a 0.50-m f/6.8 astrograph + CCD + f/4.5 focal reducer from MPC Code H06 (iTelescope, New Mexico).

On our images taken on January 22.3, 2014 we can confirm the presence of an optical counterpart with unfiltered CCD magnitude 11.3 and R-filtered magnitude 11.0 at coordinates:

R.A. = 09 55 42.17, Decl.= +69 40 25.9

(equinox 2000.0; UCAC-3 catalogue reference stars).

Our confirmation image (click on it for a bigger version):

An animation showing a comparison between our confirmation image of supernova in M82 and archive image by 2-meter telescope FTN - LCOGT (dated back to 2013-11-22). Click on the thumbnail below for a bigger version:

According to the ATel #5786 this is a Type Ia supernova with a Si II velocity of 20000 km/s (spectrum of this transient has been obtained with the Dual Imaging Spectrograph on the ARC 3.5m telescope).

UPDATE - January 22, 2014 - 1600UT

We have received an e-mail from the UCL (University College London) media office reporting that students and staff at UCL's teaching observatory, the University of London Observatory, have spotted this supernova in M82 on the night of January 21.

According to UCL website: "At 19:20 last night (21 January), a team of students assisted by Dr Steve Fossey spotted the exploding star in nearby galaxy Messier 82 (the Cigar Galaxy). The observations have been submitted to the International Astronomical Union's Central Bureau for Astronomical Telegrams, which is the official arbiter of supernova discoveries. Their official report has not yet been issued, and the supernova is therefore still nameless, but UCL appears to have been among the first, if not the first, to spot the event."

While we wait the release of the official CBET by Central Bureau for Astronomical Telegrams (CBAT) with the discovery credit, congrats to Dr Steve Fossey and his students for this discovery. While this is not the nearest supernova to Earth since the Supernova 1987A (the Type II SN 1993J in M81 was at essentially the same distance within the uncertainties as this new one in M82 and SN 2004am and SN 2008iz -detected only at radio wavelengths- occurred within M82 itself), this is the closest supernova Type Ia to Earth since SN 1972E.

Below you can see the discovery image (click on it for a bigger version).

Credit: UCL/University of London Observatory/Steve Fossey/Ben Cooke/Guy Pollack/Matthew Wilde/Thomas Wright

UPDATE - January 23, 2014 - 0800UT

According to CBET 3792 issued on January 23, Stephen J. Fossey, University of London Observatory (ULO), University College, London, reported the discovery of an apparent supernova (magnitude R = 10.5) in the galaxy NGC 3034 = M82 on CCD images obtained by himself (and assisted by students B. Cooke, G. Pollack, M. Wilde, and T. Wright) in poor sky conditions with a ULO 35-cm Schmidt-Cassegrain telescope (+ SBIG STL-6303E camera) at Mill Hill, London, on Jan. 21.805 UT. The supernova has been designated SN 2014J.


UPDATE - January 23, 2014 - 1100UT

New animation showing a comparison between an image taken on January 23, 2014 and an archive image (dated back to 2013-11-22) both by 2-meter Faulkes Telescope North (operated by LCOGT). Animation by E. Guido, N. Howes & M. Nicolini. Click on the thumbnail below for a bigger version.

UPDATE - March 02, 2014

On January 31, the Hubble Space Telescope imaged SN 2014J as it approached its peak brightness. The image, shown here as an inset, was taken in visible light with Hubble's Wide Field Camera 3. This image was superimposed into a photo mosaic of the entire galaxy taken in 2006 with Hubble's Advanced Camera for Surveys. Click on the image below for a bigger version.

Credit: NASA, ESA, A. Goobar (Stockholm University), and the Hubble Heritage Team (STScI/AURA)

by Ernesto Guido, Nick Howes & Martino Nicolini

SUPERNOVA 2013ej IN M74

Following the posting on the Central Bureau's Transient Object Confirmation Page about a possible Supernova in M74 (TOCP Designation: PSN J01364816+1545310) we performed some follow-up of this object remotely through a 0.43-m f/6.8 astrograph + CCD of iTelescope network (MPC Code  Q62 - Siding Spring, AU).

On our images taken on July 27.7, 2013 we can confirm the presence of an optical counterpart with R-filtered CCD magnitude 13.0 and V-filtered CCD magnitude 12.6 at coordinates:

R.A. = 01 36 48.20, Decl.= +15 45 31.0

(equinox 2000.0; UCAC-3 catalogue reference stars).

Our annotated confirmation image (single 120-second exposures under a cloudy sky):

An animation showing a comparison between our confirmation image and the archive POSS2/UKSTU plate (R Filter - 1990). Click on the thumbnail for a bigger version:

UPDATE - July 28, 2013

According to CBET 3606 this transient has been discovered by LOSS supernova survey on unfiltered KAIT images obtained on July 25.45.

D. D. Balam, Dominion Astrophysical Observatory, National Research Council of Canada; M. L. Graham, Las Cumbres Observatory Global Telescope, University of California at Santa Barbara; and E. Y. Hsiao, Las Campanas Observatory, report that a spectrogram (range 369-700 nm, resolution 0.3 nm) of PSN J01364816+1545310 = SN 2013ej, obtained on July 27.41 UT with the 1.82-m Plaskett Telescope of the National Research Council of Canada, shows a moderately blue continuum with weak Balmer emission lines showing P-Cyg profiles, suggesting that this is a core-collapse event.

This young type II supernova has been officially designated 2013ej.

This is the third supernova in M74 over the last eleven years (previous SN were: SN 2002ap and SN 2003gd).

Other info about this bright supernova are available through Atel (The Astronomer's Telegram):

ATel 5228: Spectroscopic classification for PSN J01364816+1545310 in M74 with FLOYDS at Faulkes Telescope South http://bit.ly/14loD8R  

ATel 5229: The Probable Progenitor of PSN J01364816+1545310 in M74 http://bit.ly/1bvU8XF

ATel 5230: Possible Spitzer Counterpart of PSN J01364816+1545310 http://bit.ly/12tjukY

Below you can see our image of supernova 2013ej IN M74 obtained on 2013 July 28.7. Click on it for a bigger version. (R-magnitude 12.8; B-magnitude 12.0)

by Ernesto Guido & Nick Howes