Supernova in M66

[ngcles]

Hi All,

I pass on to all an email notofication I recieved this morning (05072009) on the AMASTRO mailing list from Brian Skiff, to the effect that M66 has a new supernova at 11 20 17.0 +12 58 47 (J2000), nominally 28" east and 42" south of the nucleus of the galaxy. This position was provided by Brian Skiff, presumably on the basis of the CBET circular (below).

The notification is apparently in CBET 1867 (I haven't seen it myself yet). No type, faint at this stage (+15.8) but likely to brighten -- nothing else yet. M66 is relatively closeby so could end up being be quite bright.

Check it out after you've seen Saturn tonight.


Best,

Les D

[Rob_K]

Don't have access to CBET 1867 either Les, but follow-up by Swift gives v = 16.7+/-0.2
http://www.astronomerstelegram.org/?read=2109

Rochester Astronomy gives mag 16.6, but it does have the (C-band) estimate of 15.8 in its database (Monard's discovery estimate?).

So might be a bit dimmer & beyond most of us (99.99% are beyond me anyway, LOL).

Cheers -

[ngcles]

Hi Rob & All,

Yes Rob, it does seem a bit dim but there could be several reasons for this at this stage. As Brian pointed out on the AMASTRO mailing list, if it were an unobscured Type I event, we could expect it to hit mag 12.

From that, if it were a Type II event we might expect mag 14 or maybe a tad brighter at maximum light -- again assuming it is unobscured.

The fact that it is well down on this, argues either that it is still a long way from maximum light yet (and on the rise hopefully) and that it will therefore rise quite a bit in the next several days or it might be an obscured event where a fog/cloud of dust or gas in the host galaxy and between us and the supernova reduces the apparent maximum light accordingly. A possible third alternative is if it is an unusual sub-luminous event due to somehting intrinsic in the progenitor star -- possible certainly, but less likely.

No news either way yet that I know of -- we'll know in a few days I expect when someone takes an image of the spectra. I remember the M96 event (1998 bu) which was a Type I, well out in the halo and was bleedingly obvious in a 10".

M66 is at the same distance as M96 (a fraction either side of 10mpc). Assuming it is an unobscured and "normal" event we can therefore expect about mag 12 for Type I or ~14 for Type II at maximum light.


Best,

Les D

[astroron (Ron)]

Thanks for the update Les, Here's hoping it gets brighter

[Rob_K]

Originally Posted by ngcles

and was bleedingly obvious in a 10".

Cheers -

Rob 4.5"

[Rob_K]

Any more news? I notice Koichi Itagaki has some pre-discovery images up with photometry showing it rising to mag 16.3 in late June.

http://www.rochesterastronomy.org/sn2009/n3627s2.jpg

Cheers -

[glenc (Glen)]

Thanks Les.

[seanliddelow (Sean)]

Are 12inch dobsonian reflectors good for searching for supernovas?

[ngcles]

Hi All,

Brian Skiff on the AMASTRO mailing list has today indicated:

"CBET 1874 reports that a spectrum with the 2-m telescope near Hanle
in northern India shows that this is a reddened type-II supernova.
Thus though one might have hoped for a bright supernova,
it probably won't get much brighter than it is at present."

It would seem therefore that this is an obscured (reddened) TII event (core implosion of a red supergiant) dimmed by gas & dust in M66 and therefore won't achieve the brightness it might have otherwise.


Best,

Les D

[CoombellKid]

Anyone been able to get a telescopic visual on this one? Ron?

Cheers

Rob

[astroron (Ron)]

Rob, with the information from Les, and at around Mag 15.7 I don't think it will be visible in even the largest Amateur telescopes
It is also quite close to the nucleus, so if it even got down to Mag 14.7 it would be a difficult target for a visual observation.
I did look last night for a considerable amount of time but no joy
But I had a great few hours observing

[astroron (Ron)]

Originally Posted by seanliddelow

Are 12inch dobsonian reflectors good for searching for supernovas?

Sean, the short answer is Yes, I used an 8"scope for quite a few years, and was able to see but not discover Supernovae upto Mag 14.5
Send a PM to Peter Marples on this site for some help and information

[ngcles]

Hi Ron & All,

Originally Posted by astroron

Rob, with the information from Les, and at around Mag 15.7 I don't think it will be visible in even the largest Amateur telescopes
It is also quite close to the nucleus, so if it even got down to Mag 14.7 it would be a difficult target for a visual observation.

Agree completely Ron. The brightness is not the issue here -- a stellar object of mag mid 15's against "normal" sky is not a problem to see in 40cm or larger 'scopes.

The problem is seeing it against a relatively bright background like the inner halo of M66.

And yes Sean, a 12" is a perfectly sensible telescope to use for supernovae searches. I'd think if you could compile a list of galaxies out to say 40 million ly distant, in many of those any supernovae in the galaxy will be visible under a dark sky provided you are an experienced observer. The best way to become experienced is to look at a lot of galaxies.

Rev Bob Evans:

http://en.wikipedia.org/wiki/Robert_Evans_(astronomer)

discovered several supernovae using a 10" though he moved on to 16" later. His big advantage is both experience and an ability to memorise the visual appearance of 1000s of galaxies and the stars around and embedded within them. Bob can tell at a glance whether something "new" is there. His visual searches run at about 60-80 galaxies per/hr and can easily cover several hundred in a session -- all found manually and from memory.

Not worthy to carry that man's sandles ...


Best,

Les D

[Outbackmanyep]

The supernova should be able to be seen through 8" SCT with Canon 400D attached.......at least i think it should!

[astroron (Ron)]

Originally Posted by Outbackmanyep

The supernova should be able to be seen through 8" SCT with Canon 400D attached.......at least i think it should!

See this link here http://www.iceinspace.com.au/forum/s...ad.php?t=47190
Taken with a 10", so with the right gear should be no problem to image with an 8"

[astroron (Ron)]

Not worthy to carry that man's sandles ...
Les, are you saying that Bob might have a bit of outside help