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PSN J12262933+3113383

uis01's picture
uis01
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Another good target for a spectrum in a small scope to get a supernova identification:   PSN J12262933+3113383

  http://www.cbat.eps.harvard.edu/unconf/followups/J12262933+3113383.html

Its 13th magnitude in NGC 4414.

Yes, a good target Spectrum
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FMT
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Yes, a good target

Spectrum at R = 750 by Paolo Berardi on ARAS forum :

http://www.spectro-aras.com/forum/viewtopic.php?f=5&t=614

shows a somewhat inusual profile, with no proeminent (either emission and absorption) lines

Gianluca Masi also got a spectrum with a starnalyser

François Teyssier

PSN J12262933+3113383
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Robin Leadbeater
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Now confirmed as SN 2013df (CBET 3557)as type II with a weak P Cyg H alpha line in a spectrum from Keck II

Note GELATO correctly classified it from Paolo's spectrum as type II despite no obvious H alpha emission.  

How/where  should we publish  amateur spectra of PSN  in a timely fashion ?

Robin

Spectra of PSN would be
uis01's picture
uis01
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Spectra of PSN would be sumbitted the same way that photometry of PSN are updated, through the "Transient Objects Confirmation Page" at CBAT:

http://www.cbat.eps.harvard.edu/unconf/tocp.html

The way that PSN earn their designation and get promoted from probable to actual these days is through the spectroscopic confirmation.  So I am happy to assist anyone if it turned out they wanted any of you to write a CBET to announce the upgrade of an object to actual SN.

It looks like from CBET 3557 that the Keck II beat you guys to this one with a spectrum taken a few days ago (but just announced).  I'll keep an eye on the TOC page and continue to post the good bright candiates here.  Its just a matter of time until one of you guys beat the big scope competition.

SN 2013df - one to watch?
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Robin Leadbeater
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I can't access CBETs unfortunately, the gist of it was relayed to me second hand (The decision to charge  for  them still rankles) but Gianluca's original Star Analyser spectrum was taken 2013-06-08 T 22:41 just after this image

 http://www.virtualtelescope.eu/2013/06/09/psn-j122629333113383-in-ngc-4414-8-june-2013/

This rather unusual one with its very weak H alpha (Still undectable in the latest low resolution spectrum by Christian Buil) was probably always going to need a good spectrum to be sure  of a classification though.  But because of this, it could be an interesting one to watch to see how it evolves.

Robin

According to the CBET, the
uis01's picture
uis01
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According to the CBET, the Keck II spectrum didn't show much more detail then the small scope ones shared here.  It is puzzling that this SN doesn't have detectable emission lines.  The excuse de-jour is that it might be "early" and that the emission lines will appear later.  Astronomers are guessing it might turn into a II-b.  I'm not sure exactly how the physics of that works within the framework of the existing physical models.  

SN2013df Type IIb
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A IIb is like SN1993J was in M81. They start showing Hydrogen in the spectra early and then over time the H dissappears and the SN looks more like a Type Ib. (WR progenitor? or stripped by a white dwarf?). It make me wonder if more Type Ibs start out as IIbs, only most are not found this early. It'll be interesting if a progenitor is found in old HST or other big scope's images. 

Need fainter seq
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Thanks to the chart team for getting it done so quickly! I observed it visually last night at 14.6, it might be good to extend the seq fainter than 151, in case it starts to fade soon. Tnx.

Mike LMK

AAVSO 49 Bay State Rd. Cambridge, MA 02138 aavso@aavso.org 617-354-0484