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another potentially bright supernova 2020hvf in NGC 3643

PostPosted: Wed Apr 22, 2020 10:47 pm
by Robin Leadbeater
https://wis-tns.weizmann.ac.il/object/2020hvf

This is another type Ia so although only ~mag 17 currently it should reach ~mag 12.5-13 based on the redshift distance

Cheers
Robin

Re: another potentially bright supernova 2020hvf in NGC 3643

PostPosted: Wed Apr 29, 2020 12:35 am
by Robin Leadbeater
This supernova is now much brighter (mag 14 on 2020-04-27).

sn2020hvf_guider_9x10s_annot.png
sn2020hvf_guider_9x10s_annot.png (221.8 KiB) Viewed 2968 times


Here is the spectrum with the ALPY200 but it is bright enough now for any low resolution spectrograph
Although it is officially classified as a type Ia it is peculiar and does not give a good match in either GELATO or SNID.

Image

Cheers
Robin

Re: another potentially bright supernova 2020hvf in NGC 3643

PostPosted: Sat May 09, 2020 8:15 am
by Frederic Pastor
Hi Robin,

Many thanks for your alert and your are right: Sn bright enough now to get my Alpy out on this target. I estimate more a Mag between 13 and 14 but I haven't calculate it yet, by comparison with the bright star just beside.

Below my contribution, I tried to push further until one hour exposure:

rspec Sn2020hvf 08 05 2020.jpg
Sn
rspec Sn2020hvf 08 05 2020.jpg (81.75 KiB) Viewed 2498 times


guidage Sn2020hvf.jpg
guidage


Cheers

Fred

Re: another potentially bright supernova 2020hvf in NGC 3643

PostPosted: Sat May 09, 2020 10:52 am
by Robin Leadbeater
Hi Fred,

Nice spectrum ! According to the images in rochersterastronomy it had reached Vmag 12.7 last night so probably near maximum
http://www.rochesterastronomy.org/sn2020/sn2020hvf.html

I am still trying to understand why I could not get a good match for my spectrum in SNID or GELATO. Perhaps it was too young then. If you post your fits file somewhere, I can run it through SNID and see if it gives a match now (I now put a copy of all my spectra in the BAA database future security https://britastro.org/specdb/data.php )

Cheers
Robin

Re: another potentially bright supernova 2020hvf in NGC 3643

PostPosted: Sat May 09, 2020 1:59 pm
by Frederic Pastor
Many thanks Robin.
At Mag 12.7, this explain why the catch wasn't that difficult !
And a perfect period to carry on 'shooting' this Supernova, if the weather is with us.
I have just sent to you my FITS file on your email adress. Hope this will help. Not yet registered on BAA database. Now I will try to better understand this peculiar spectra, as you mentioned it.
Cheers.
Fred

Re: another potentially bright supernova 2020hvf in NGC 3643

PostPosted: Sat May 09, 2020 5:36 pm
by Robin Leadbeater
Frederic Pastor wrote:Many thanks Robin.

I have just sent to you my FITS file on your email adress.
Cheers.
Fred


Thanks Fred,

SNID gives a good fit to your spectrum for several type Ia near maximum. Here is a typical one. (The supernova was very young when I measured it. Perhaps SNID/GELATO do not have enough examples of young supernovae to compare with)

Cheers
Robin

_sn2020hvf_20200508_852_fred_pastor_crop_comp0003_snidflux.png
_sn2020hvf_20200508_852_fred_pastor_crop_comp0003_snidflux.png (41.16 KiB) Viewed 2420 times

Re: another potentially bright supernova 2020hvf in NGC 3643

PostPosted: Mon May 11, 2020 11:48 am
by Frederic Pastor
Hi Robin,

SNID fitting is very interesting, and encouraging. To complete your matching, I may add that the SN1995al also fit perfectly this young 2020hvf, confirming a phase of -2.2 days and the type Ia :

gelatoplot.png
Sn1995al
gelatoplot.png (61.01 KiB) Viewed 2291 times


I have filtered a bit my spectrum to get it more smooth. And tried to find some Calcium and Silicium lines, as a first approach of understanding. Wasn't that easy in such a turbulent object. Do not hesitate to give your opinion :D

Sn2020hvf wavelenght.jpg
sn filtered
Sn2020hvf wavelenght.jpg (91.33 KiB) Viewed 2291 times


Cheers,

Fred

Re: another potentially bright supernova 2020hvf in NGC 3643

PostPosted: Tue May 12, 2020 9:58 am
by David Boyd
This spectrum of type 1a supernova SN2020hvf was taken with a LISA spectrograph (R~1100) on a C11 and has been calibrated in absolute flux using a V magnitude of V=12.67 measured concurrently with the spectrum using another scope. The spectrum has been smoothed with a Gaussian factor 2.5.
The blue-shifted location at 6118A of the prominent Si II 6355A absorption feature indicates an expansion velocity of ~11,200 km/s.
David
sn2020hvf_20200511_918_D_Boyd.png
sn2020hvf_20200511_918_D_Boyd.png (33.12 KiB) Viewed 2193 times

Re: another potentially bright supernova 2020hvf in NGC 3643

PostPosted: Tue May 12, 2020 10:20 pm
by Alun Halsey
SN2020HvF.JPG


This is my very first attempt at capturing spectra of a supernova,this was taken on the night of 11/12th using ALPY 600,SX TRIUS 825 on a C9.25 with 6.3x reducer. 4x900sec calibrated using Ar/Neon lamp in calibration module. Also signed up to Gelato this evening and received this result of 100% type la

Alun

Re: another potentially bright supernova 2020hvf in NGC 3643

PostPosted: Wed May 13, 2020 3:57 pm
by Forrest Sims
Hi all,

Thanks Robin for the alert on this SN.

Here is what it looks like 2 days later. This spectrum includes (9) 600sec exposures while guiding with the target on the slit. (I did manage to simultaneously acquire narrowband filter data but have not had time to assemble an ensemble as it were to do the photometry and therefore flux calibrate this spectrum.)
Cheers
Woody Sims

sn2020hvf_20200513_176_Forrest Sims.png