Supernova in M82: Astrophotographers Wanted

[Integral]

A Super nova is just getting warmed up in M82. Note for you astrophotographers, they are looking for any recent photos of this piece of sky .

 

[Drakkith]

Nice. Just wish we'd see a supernova here in the Milky Way.

 

[turbo]

But not too close.

 

[mfb]

Nice. Just wish we'd see a supernova here in the Milky Way.

We had bad luck in that respect. They are expected with a rate of 2-3 per century, and the last visible one was 1604 (but astronomers found more recent remnants). Three years before the first telescope was built...
Anyway, even if dust could block our view, the neutrino detectors will certainly note the next one.

 

[Chronos]

Fortunately, supernova candidates in our locality are quite rare. The nearest known potential progenitor is IK Pegasus at around 150 light years. It is suspected it will probably meet its demise as a type Ia supernova. It is retreating so by the time it pulls the plug it will be even more remote from earth. A type Ia supernova could possibly adversely affect Earth as far out as about 100 light years, so it looks like we are pretty safe.

 

[Vanadium 50]

They are expected with a rate of 2-3 per century

I keep hearing that number, and find it hard to believe. OK, so we can only see 15% of our galaxy. How many SN have we seen in M31 since 1800? That would be one, in 1885. How many in M33 in the same period? That would be zero. And it's not like I am cheating and picking ellipticals.

 

[glappkaeft]

Both M31 and M33 are thought to have low SN rates. For M33 it's 1 per 360 years (per http://iopscience.iop.org/0067-0049/117/1/89 ).

 

[adjacent]

I would like to see a supernova as bright as the Crab nova

 

[Vanadium 50]

I agree they have low SN rates. That's the implication from not seeing many. The question is why in light of this we think our own galaxy has SN rates an order of magnitude higher.

 

[mfb]

Looks like the estimate comes from galaxies that are similar to ours.

Astronomers regularly observe supernovae in other galaxies like ours. Based on those observations, researchers estimate about three explode every century in the Milky Way.

http://www.nasa.gov/home/hqnews/2008/may/HQ_08126_Chandra_Supernova.html

We had one in 1603, there are known remnants from one in ~1680 and one in ~1870. As we certainly don't know all of them, a rate of at least 1/(200 years) looks reasonable, and 2-3 per century are possible. We can be sure no supernova in our galaxy happened in the last 20 years, as neutrino detectors would not miss that.

All times are "as seen on earth", of course.

 

[glappkaeft]

I agree they have low SN rates. That's the implication from not seeing many. The question is why in light of this we think our own galaxy has SN rates an order of magnitude higher.

There are several competing methods that all give a similar rate.

Here ( http://xxx.lanl.gov/ftp/astro-ph/papers/0601/0601015.pdf ) is one recent paper using the INTEGRAL satellite.

 

[Philosophaie]

I believe that the Supernova is in the Cigar Galaxy M82 NGC3034 in UMa at around RA=135.93 and DEC=69.68 if I am not mistaken.

 

[Vanadium 50]

Thanks for the link: note that what they call the best estimate is 67 years (and theirs is 53 years).

 

[davenn]

I believe that the Supernova is in the Cigar Galaxy M82 NGC3034 in UMa at around RA=135.93 and DEC=69.68 if I am not mistaken.[/QUOTE]

yes you are mistaken, did you not read the link in the OP ? it has the co-ordinates in there

you can't have a RA of 135 as RA is measured in Hours, Minutes and Seconds 135 hours isn't possible
as there is a max of 24 hours

Dave

 

[Bandersnatch]

When's the expected peak in brigthenss? My binoculars are itching.

 

[|Glitch|]

I believe that the Supernova is in the Cigar Galaxy M82 NGC3034 in UMa at around RA=135.93 and DEC=69.68 if I am not mistaken.

Coordinates: R.A. = 09 55 42.15, Decl.= +69 40 25.8 (2000.0)
PSN J09554214+6940260 is offset 54" west, 21" south from the nucleus of M82

Source: http://www.aavso.org/aavso-alert-notice-495

 

[Drakkith]

When's the expected peak in brigthenss? My binoculars are itching.

I think they have a cream for that.

 

[Philosophaie]

you can't have a RA of 135 as RA is measured in Hours, Minutes and Seconds 135 hours is'nt possible
as there is a max of 24 hours

Sorry Dave and |GLITCH|. RA and DEC are in decimal degrees there. I use degrees in my calculations and I forgot to convert it back.

This is at J2000. The position at 1-1-2000 at Greenwich 12 Midnight.

Do not confuse it with its companion galaxy M81 also in Ursa Major: Bode's Galaxy, NGC3031.

 

[|Glitch|]

According to the spectra for SN2014J at +3 days, it shows strong Silicon II absorption line at 607 nm.

At rest, the Silicon II absorption line should be 635.5 nm. Which would mean the spectra is blue-shifted by 4.48% the speed of light. Which would put the speed of the ejecta at ~13,445 km/s.

That would seem to rule out the possibility of SN2014J being a Type Iax SNe, which all have ejecta traveling less than 8,000 km/s.