another potentially bright supernova 2020hvf in NGC 3643

[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

[Robin Leadbeater]

This supernova is now much brighter (mag 14 on 2020-04-27).

sn2020hvf_guider_9x10s_annot.png (221.8 KiB) Viewed 12980 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.



Cheers
Robin

[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:

Sn

rspec Sn2020hvf 08 05 2020.jpg (81.75 KiB) Viewed 12510 times

guidage

Cheers

Fred

[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

[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

[Robin Leadbeater]

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 (41.16 KiB) Viewed 12432 times

[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 :

Sn1995al

gelatoplot.png (61.01 KiB) Viewed 12303 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

sn filtered

Sn2020hvf wavelenght.jpg (91.33 KiB) Viewed 12303 times

Cheers,

Fred

[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 (33.12 KiB) Viewed 12205 times

[Alun Halsey]

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

[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