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The AAVSO and preparation for the next visible Milky Way supernova

wel
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The last very bright supernova in the Milky was occurred in 1604. Estimates of how frequently such supernova are visible - on average - disagree by a factor of a few, but one per century is not far from the mark. So our recent experience with accurately measuring Nova Del 2013 - which peaked at the faint end of naked eye visibility - suggests a few things:

- the AAVSO *can* play a very important role - even the most important role - in obtaining calibrated photometry of very bright objects.

- we need to seriously plan and prepare if we are to have a hope of measuring a really bright transient accurately!

By the time such a supernova occurs, it will be too late to work out the wrinkles. If you think saturation and comp stars are an issue at mag 5, try mag -4!

Just a thought!

Doug

Viva the visual observer.
hhu
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Viva the visual observer.  Fast and no saturation :)

HHU, What comp stars will
wel
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HHU,

What comp stars will you be using?

Cheers,

Doug

...but lack of comparison
Bikeman
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...but lack of comparison stars :-( if it's really bright . Oh, and will it even be safe to look at an SN of say alpha Orionis with unprotected eyes?

Not all galactic SN must be really super bright tho, apparently the one that formed the SNR around Cas A was practically unnoticed when it happened ca 300 yrs ago, according to the dominating theory.

What is remakable about galactic SN is, that if this will be a core collapse SN, we might actually get early warning by neutrino detectors (neutrinos start their travel to us at the very moment of the core collapse, while the light from the SN is emitted only after the shock front of the core collapse has travelled thru the star). Since those detectors have not the best angular resolution of the source of the detected neutrinos, the first challenge for pros and also amateurs might be to look for the SN after such an early warning and be the first to report the coordinates.


To get early warning from neutrino detectors, everyone can subscribe to the mailing list of SNEWS (Super Nova Early Warning System) : http://snews.bnl.gov/ , so this should be the first step IMHO in getting prepared for the ultimate light show.

 

CS

HB

 

 

 

 

It *is* possible to have
wel
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It *is* possible to have visual estimates if one can create an artificial comp star using, say, a white LED that has the ability to be changed in brightness precisely. It could position a fixed (significant) distance from the visual observer in the direction of, say, a bright star, adjusted to match it and then moved in the direction of the bright transient, like one of the historical supernovae and adusted to match its brightness. The calibrated change in flux would give the magnitude difference. But without such a device and if the transient was sufficiently bright and/or Jupiter or Venus were not in the sky to act as a comp star, a visual estimate would not have sufficient precision to be useful.

Cheers,

Doug

Interesting thread.  I was
cpmalo87
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Interesting thread.  I was just thinking about this issue as my wife and I were driving west after sunset.  Venus must be close to m=-3 right now.   Has anyone tried to develop such a technique? I wonder what the peak wavelength of a typical 'white light' led is.

I was just trying to be funny
hhu
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wel wrote:

HHU,

What comp stars will you be using?

Cheers,

Doug

 

I was just trying to be funny but it actually started a serious topic. 

early images
Bikeman
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I would not be surprised if the first couple of hundreds of pictures of the next galactic SN (if it's really bright) will be taken with smart phone cameras ("Oh, wow, what's that??? Let's try to take a picture and twitter it!"). I'm skeptical whether that will be of much use, but maybe there are ways to characterize those cameras sufficiently well to make some use of it .

CS

HB

 

Reversed binoculars
AAX
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Very interesting the use of LED, Doug.

One technique that can be useful is "reversed binoculars", if the bright object is visible at night.

(1) point a 7x50 or 10x50 bino "at wrong way" to a bright object, e.g. Venus, Jupiter or Sirius. These objects will appear like 2nd, 3rd or 4th-magnitude stars.

(2) compare the dimmed magnitude objects through reversed binos with naked eye comp stars

(3) take the difference, e.g. Jupiter (mag -2) seems like mag +3 through reversed bino, so the difference is "5". The reversed bino dimmed the magnitude by a factor 5.

This technique is useful to estimate the brightness of total eclipse moon.
It'll important to take another situations like atmospheric extinction and comps' colors. A set of experiments will help.

This possibility is one
GlennWGE
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This possibility is one reason I keep my SSP-3 locked and loaded at all times.  GW

Amen!  Matt told me last fall
uis01
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Amen!  Matt told me last fall at the AAVSO meeting that I was one of maybe a dozen still using that equipment and he encouraged me not to stop because it quantitatively ties together the digital and unaided eye regimes.

Camera response?
KBJ
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For a rough guide, could you, for instance, use a camera with a linear response and compare exposure times used to create similarly saturated images of the SN and a bright star?  2.5 times the exposure time would represent one magnitude difference, 100 times the exposure time 5 magnitudes.  Would it put you in the ballpark?

Rob Kaufman KBJ

AAVSO 49 Bay State Rd. Cambridge, MA 02138 aavso@aavso.org 617-354-0484