Alert Notice 479: Supernova 2013aa in NGC 5643 = PSN J14323388-4413278

February 17, 2013

Event: Supernova 2013aa in NGC 5643 = PSN J14323388-4413278

Discovered by: Stuart Parker (Canterbury, New Zealand)

Discovery Date: 2013 Feb. 13.621 UT

Discovery Magnitude
: red mag 11.9 on a 30-s unfiltered CCD image taken with a 30-cm Astro-Tech AT12RC Ritchey-Chretien astrograph (+ ST10 camera) at his Parkdale Observatory in the course of the Backyard Observatory Supernova Search (BOSS)

: R.A. 14 32 33.88  Decl. -44 13 27.8  (2000.0)
SN 2013aa is 74" west and 180" south of the nucleus of NGC 5643. Position measured by Colin Drescher, Calamvale, QLD, Australia.
Spectra: Spectroscopy obtained by J. T. Parrent, Las Cumbres Observatory Global Telescope (LCOGT) and Dartmouth College; D. Sand, Texas Tech University; and S. Valenti, M. L. Graham, and D. A. Howell, LCOGT and University of California at Santa Barbara, robotically with the FLOYDS (FTS) spectrograph on 2013 Feb. 15.70 UT shows SN 2013aa to be a type-Ia supernova, discovered a few days before maximum light. They obtained a second spectrogram with the Gemini Multi-Object Spectrograph (GMOS) on the 8-m Gemini South telescope on Feb. 15.38 that confirmed the classification.  

Observations reported to the AAVSO:
2013 Feb. 15.73392 UT, 11.910 V +/-0.004 (Peter Nelson, Ellinbank, VIC, Australia);
15.73866, 11.999 B +/-0.003 (Nelson);
16.12429, 11.6 (Alexandre Amorim, Florianopolis, Brazil);
16.29380, 11.5 (Amorim);
16.39469, 11.784 V +/-0.005 (Franz-Josef Hambsch, Mol, Belgium);
16.39508, 11.774 V +/-0.005 (Hambsch);
16.56218, 11.822 B +/-0.030 (Terry Bohlsen, Armidale, NSW, Australia);
16.56448, 11.823 V +/-0.053 (Bohlsen);
16.56676, 11.652 R +/-0.035 (Bohlsen);
16.56926, 11.668 I +/-0.053 (Bohlsen);
16.88193, 11.5 (David Blane, Henley-on-Klip, South Africa);
17.39803, 11.720 V +/-0.005 (Hambsch);
17.39845, 11.728 V +/-0.005 (Hambsch);
17.39889, 11.680 I +/-0.011 (Hambsch);
17.39928, 11.667 I +/-0.011 (Hambsch);
17.68800, 11.848 V (Artyom Novichonok, Kondopoga, Russia);

Charts: Finder charts for SN 2013aa may be plotted using the AAVSO Variable Star Plotter (VSP) at

Reporting Observations
: Please report all observations to the AAVSO International Database as SN 2013aa.

a. Announced as a transient in AAVSO Special Notice #337 (Matthew Templeton, AAVSO), and as a supernova in Central Bureau for Electronic Telegrams No. 3416 (Daniel W. E. Green, ed.) and in ATel #4817 (

b. The object was designated PSN J14323388-4413278 when posted on the Central Bureau for Astronomical Telegrams' Transient Objects Confirmation Page (TOCP) webpage, and was designated SN 2013aa based on spectroscopic reports.
c. Nothing was visible down to magnitude 19 at this position on an image taken 2013 Feb. 1.602 UT by Parker or on Digitized Sky Survey red and infrared images.

d. Image by Parker posted at

Congratulations to Stuart Parker on his latest discovery!

This AAVSO Alert Notice was compiled by Elizabeth O. Waagen.


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