Where to hunt for supernovas?

[Frida Space]

Hi everyone. As part of a school project we will be using our telescope to try to discover new extragalactic supernovas. Does anyone have any suggestions as to where to look? I think it might be a good idea to look somewhere close to Polaris as it will be visibile all year long, and at the same time somewhere far away from (possibly perpendicular to) the galactic plane, so that it should be easier to see galaxies (I think). However I have never done anything of this kind so I'm really not sure. (We are located in the northern hemisphere but we rent telescopes in Siding Springs, Australia, so no problem with hemisphere visibility).

Any other kind of suggestions/tips/etc. is very deeply welcomed!

Edit: ^supernovae not supernovas... *facepalm*

[LordFerret]

I'm sure you've seen this already? If not, might be of some help.

http://scienceblogs.com/startswithabang/2013/05/24/how-to-find-your-very-own-supernova/

Edited October 8, 2015 by LordFerret

[YNM]

Have you tried AAVSO ? They always get immediate notices of novaes, more so for those within amateur limit.

EDIT : Additionally, if you want to search for SN in past times instead, maybe you want to dig some archive like Hubble or sky surveys archive.

EDIT 2 : Hmm... You can also just look at virgo cluster (which extends from Virgo to Ursa Major). Or of you really rent a 'scope in Siding Springs, may as well you dig into their archive !

Edited October 9, 2015 by YNM

[Shpaget]

Polaris is not visible from Siding Springs.

According to ESA, the rate of SN in Milky Way is one in 50 years.

If we assume similar rate in similar galaxies, you'll need quite a few of them in your view to catch one in a reasonable time.

[UmbralRaptor]

Use whichever scope has greatest étendue, and hit every nearby cluster visible from Siding Springs. (Practically speaking, one supernova per milky way like galaxy per 50 years is grossly optimistic.) If archival data is allowed, it might be worth poking around with WISE or SDSS.

[YNM]

Hmm... Siding Springs is also a comet/asteroid hunting site, so I suppose you could ask them their database as well... Spotting for a supernova then in one of their images.

For SN in southern hemisphere, there's some galaxy cluster in the area of Norma or so ? That being said, good luck with the project ! May the luck be with you...

[legoclone09]

Just look for a big explosion. Shouldn't be too hard to find.

[GoSlash27]

FridaSpace,

I'm not an astronomer and I don't play one on TV, so take anything I say with a grain of salt.

IIRC, not every star is capable of going supernova. You want something that's 1)hot 2) big and 3) old.

Ideally a group of blue giants in a globular cluster would be ideal by my understanding. They'll fit the bill.

We have a few of those hanging around our galaxy outside of the galactic plane.

Look for a spherical glob of blue- white stars with no clear structure away from the Milky Way and focus on that.

Of course, I could be totally wrong

Best,

-Slashy

Edited October 11, 2015 by GoSlash27

[Robotengineer]

How big is the telescope? AFAIK, it's nearly impossible to see extragalactic supernovae without a VST (Very Serious Telescope) probably with a diameter greater than 12" or 350 mm.

[Frida Space]

I'm sure you've seen this already? If not, might be of some help.

http://scienceblogs.com/startswithabang/2013/05/24/how-to-find-your-very-own-supernova/

Thank you very much, it contains useful information.

Have you tried AAVSO ? They always get immediate notices of novaes, more so for those within amateur limit.

Thanks, I'll take a look.

Polaris is not visible from Siding Springs.

According to ESA, the rate of SN in Milky Way is one in 50 years.

If we assume similar rate in similar galaxies, you'll need quite a few of them in your view to catch one in a reasonable time.

Oops, I guess one close to Sigma Octantis then. Yea, our plan is to monitor a lot of galaxies. It's also a long-term project, so we might as well wait years. Thank you for your advice.

Use whichever scope has greatest étendue, and hit every nearby cluster visible from Siding Springs. (Practically speaking, one supernova per milky way like galaxy per 50 years is grossly optimistic.) If archival data is allowed, it might be worth poking around with WISE or SDSS.

Thanks. Clusters! I hadn't thought of them. That's smart.

Hmm... Siding Springs is also a comet/asteroid hunting site, so I suppose you could ask them their database as well... Spotting for a supernova then in one of their images.

For SN in southern hemisphere, there's some galaxy cluster in the area of Norma or so ? That being said, good luck with the project ! May the luck be with you...

Thank you

Just look for a big explosion. Shouldn't be too hard to find.

It's probably just a matter of experience. I know a supernova hunter in Italy who just found three supernovas in one week. It will be difficult at first, but after a while, if we're lucky, we should find one, I hope!

Ideally a group of blue giants in a globular cluster would be ideal by my understanding. They'll fit the bill. We have a few of those hanging around our galaxy outside of the galactic plane. Look for a spherical glob of blue- white stars with no clear structure away from the Milky Way and focus on that.

Thank you, that seems interesting. I'll do further research, thanks again

How big is the telescope? AFAIK, it's nearly impossible to see extragalactic supernovae without a VST (Very Serious Telescope) probably with a diameter greater than 12" or 350 mm.

We can rent anything from a toy telescope to a Planewave CDK 700 mm and further. I think that should be enough to find extragalactic supernovae, some of them are very bright (15.0 or less)

[UmbralRaptor]

IIRC, not every star is capable of going supernova. You want something that's 1)hot 2) big and 3) old.

Ideally a group of blue giants in a globular cluster would be ideal by my understanding. They'll fit the bill.

We have a few of those hanging around our galaxy outside of the galactic plane.

Look for a spherical glob of blue- white stars with no clear structure away from the Milky Way and focus on that.

Of course, I could be totally wrong

Partially wrong. High mass (≥8 M_{☉}) blue/red giants do go supernova, but they don't live very long anyway. You'll tend to find them in or near regions of high star formation. There are also Type Ia supernovae, which have a different mechanism involving white dwarf stars. Those ones can happen most-anywhere in a galaxy. But the aforementioned 1 supernova per milky way per 50 years is for the galaxy as a whole! (And again I would expect it to be an overestimate and/or to fail to account for extinction from dust/gas)

Thanks. Clusters! I hadn't thought of them. That's smart.

Just to clarify, I mean galaxy cluster, not star cluster. Supernova rate even in something like the Tarantula Nebula is way too low unless you can keep a scope on it for a few million years.

Just look for a big explosion. Shouldn't be too hard to find.

In that they'll generally stand out nicely from their host galaxy and brighten and fade in a few weeks, yes. But they're quite rare in any one galaxy, so with an insufficient sample one could be waiting for centuries...

[Frida Space]

Just a quick update, yesterday we managed to image our first supernova, ASASSN-15qc in UGC 402, a very dim and small galaxy, however the supernova is very, very bright (that's why we chose it). What striked me the most is that our unprocessed image, obtained from a single 500-second esposure, was basically just as good as a mosaic of 10 different 10 minute exposures.

[legoclone09]

Ooh! You found one! And I am assuming the dot where the two lines would intersect is it, so congratulations! Name it something KSP-related. Or whatever you like, really.

EDIT: Looked it up, many sources say it probably is one so good job! Hope you get to name it! Or at least be a contributor to finding it, if that is how it works.

Edited October 14, 2015 by legoclone09