ASAS-SN request AT2018oh

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Robin Leadbeater
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ASAS-SN request AT2018oh

Post by Robin Leadbeater »

I have had a request for a spectrum of possible supernova AT2018oh/ASAS-SN18bt discovered today (mag 15)
https://wis-tns.weizmann.ac.il/object/2018oh
I am clouded out again tonight but perhaps someone else might like to try.
Below is the email request

Cheers
Robin

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
From: Subo Dong
Sent: Sunday, February 04, 2018 4:32 PM
To: Robin Leadbeater
Cc: Jose Prieto ; Krzysztof (Kris) Stanek
Subject: ASASSN-18bt

Dear Robin,

ASAS-SN has just discovered ASASSN-18bt (2018oh on TNS). It is in the Kepler's K2 field so could be of great interest with high-cadence Kepler observations. Could you please take a spectrum if possible?

https://wis-tns.weizmann.ac.il/object/2018oh


Best,
Subo
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Robin Leadbeater
Posts: 1926
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Re: ASAS-SN request AT2018oh

Post by Robin Leadbeater »

I managed to get 10 mins on it in a break in the clouds. It is a type Ia.
https://wis-tns.weizmann.ac.il/object/2018oh
(spectrum and typical SNID fit below)
It could reach ~mag 14 in the next few days.

Cheers
Robin
Attachments
at2018oh_SNID_fit.png
at2018oh_SNID_fit.png (39.88 KiB) Viewed 14567 times
LHIRES III #29 ATIK314 ALPY 600/200 ATIK428 Star Analyser 100/200 C11 EQ6
http://www.threehillsobservatory.co.uk
Robin Leadbeater
Posts: 1926
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Re: ASAS-SN request AT2018oh

Post by Robin Leadbeater »

This supernova which I officially classified spectroscopically on TNS as a type Ia is the subject of a feature on the Sky and Telescope website this week
https://www.skyandtelescope.com/astrono ... -surprise/
(The paper mentioned there cites my classification)
There are other papers comming to press on this SN which add to the debate on what the progenitor systems of type Ia SNe look like ( eg the traditional model of accretion onto a white dwarf from a companion star or a merger of two white dwarfs, an alternative which has been gaining support in recent years)

Robin
LHIRES III #29 ATIK314 ALPY 600/200 ATIK428 Star Analyser 100/200 C11 EQ6
http://www.threehillsobservatory.co.uk
James Foster
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Re: ASAS-SN request AT2018oh

Post by James Foster »

On page 19 of https://arxiv.org/pdf/1811.10061.pdf :
"Leadbeater, R. 2018, Transient Name Server Classification Report, 159"

James
James Foster
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Hamish Barker
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Re: ASAS-SN request AT2018oh

Post by Hamish Barker »

Belated congrats robin. Must be quite satisfying!
Robin Leadbeater
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Re: ASAS-SN request AT2018oh

Post by Robin Leadbeater »

Thanks Hamish,

I was invited to give a short talk in the Pro-Am session of the UK National Astronomy Meeting in a couple of days and SN2018oh will get a mention.
https://nam2019.org/thursday/details/23/325
The debate about whether type Ia are caused by accretion or white dwarf mergers is still far from settled though.

Cheers
Robin
LHIRES III #29 ATIK314 ALPY 600/200 ATIK428 Star Analyser 100/200 C11 EQ6
http://www.threehillsobservatory.co.uk
Hamish Barker
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Re: ASAS-SN request AT2018oh

Post by Hamish Barker »

I guess ligo isn't sensitive enough to detect white dwarf mergers. ( or would it if inside the milky way?) Otherwise might be a way to settle it.)
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