SN 2014G

Supernova Type II-L SN 2014GIn late 2012, the supernova impostor SN 2009ip in NGC 7259 brightened in an event that had similarities to a Type IIn supernova. During that event we observed bumps in the decline from peak brightness that have been observed in other Type IIn supernovae but have not been well studied.

SN 2014G is a supernova in NGC 3448 that was originally classified at a Type IIn (CBET 3787). This galaxy is relatively nearby (cosmically speaking) so SN 2014G was potential one of the brightest Type IIn events as observed in the visual by earth-bound telescopes over the last two years. We started following it to see if it has bumps in its decline (like the last event of SN 2009ip).

Spectra taken several weeks after the peak brightness (see below) revealed that SN 2014G is actually probably a Type II-L (ATEL #5935). We are continuing to observe it anyway, with a somewhat lower expectation that we may see bumps and dips like those observed in the 2012-A eruption of SN 2009ip.

I want to thank and acknowledge Douglas Barrett, Alberto Betzler, Andy Cason, Walt Cooney, Tõnis Eenmäe, Raymond Kneip, and Massimiliano Martignoni for contributing observations they have made with their own equipment or obtained through there personal iTelescope accounts.

What's New Today

April 20, 2017 UT

  • Have completed follow-up deep imaging of the galaxy almost three years after the SN event. (not yet included on plots).

June 21, 2014 UT

  • Walt Cooney from Sonoita Research Observatory is pitching in with some images to help cover the tail end of the light curve.

June 15, 2014 UT

  • Added slides from talk at SAS/AAVSO meeting under "Publications"

  • I have finished applying the first run at the color transformations. The resulting data looks good.

Publications

Here is a list of publications and presentations we have used to disseminate the results of this project.

Photometry

Coordinate with us!

If you are observing SN 2014G we would like to coordinate with you to ensure the best possible coverage for this object with the least amount of systematic noise between observers. Your data will remain yours to post on whatever other forum or site you wish. I am OK with people who are coordinating with us posting photometry to the AAVSO of VSNET on your own. As a thank you though, I will when the project is completed, process your data for you and return file with your measurements in the prescribed format that you can upload for credit under your observer ID.

We would like to coordinate coverage, have copies of your images, and include you as an author on any publications that use your data. Email jmart5 _at_ uis.edu (or contact me on the AAVSO website as user UIS01) for more information.

Sources of Data

The plots (unless otherwise noted) are a compilation of data from the following sources:

  • Douglas Barrett (France) using his own Altair-Astro 8-inch ritchey-chretian

  • Alberto Silva Betzler (Brazil) using iT21 on the iTelescope network.

  • Andy Cason (Georgia, USA) using his own 10-inch LX200 telescope -or- iT5, iT11, and iT21 on the iTelescope network.

  • Walt Cooney (Arizona, USA) using the Sonoita Research Observatory (SRO) 50cm telescope

  • Tõnis Eenmäe (Estonia) at Tartu Observatory

  • Raymond Kneip, (Luxembourg) using iT11 and iT18 on the iTelescope network.

  • Massimiliano Martignoni,(Italy)using a S-C 25cm-f/10.0 telescope and KAF0261E CCD camera.

  • J.C. Martin et al. U of IL Barber Observatory

Comparison Stars

We are using a sequence of 10 comparison stars provided by the American Association of Variable Star Observers (AAVSO) covering the range from V = 12.1 - 16.4. This sequence can be downloaded by referencing chart 13190JQ or 'SN 2014G' on the AAVSO's Variable Star Plotter.

Since the size of the field for each telescope varies, we cannot use all of the comparison stars for every image. We will assess the systematic offsets that occur as a result of this and correct for them later in the project. Right now the resulting systemics still exist in the plot below.

We have been using VPHOT to reduce the photometry from the images. Our calculated statistical errors on the solution range normally from 0.02 to 0.08 magnitudes.

BVRI Photometry

The data plotted are from sources listed above.

SN 2014G in NGC 3448
Photometry of SN 2014G

Other web pages

SWIFT Photometry

The SWIFT satellite has also taken images of SN 2014G. A plot of the brightness measured by SWIFT is shown below. Note that this image was not generated by us. It is from the SWIFT Supernova webpage run by Peter Brown.

Spectroscopy

Spectra were obtained by Tõnis Eenmäe of Tartu Observatory 1.5 m Telescope and with the ASP-32 spectrograph on 18 Feb 2014 UT and Roberta Humphreys and Sklyer Grammer with the Multiple Mirror Telescope Hectospec MOS on 25 Feb 2014 UT.

SN 2014 G with the VLT Hectospec

Last Updated: UT 2017 April 20