[AZ-Observing] Re: Another Sun Time-lapse Movie
- From: Steven Dodder <sdodder@xxxxxxxxxxx>
- To: Az Observing <az-observing@xxxxxxxxxxxxx>
- Date: Fri, 23 Dec 2011 18:59:53 +0000
Placing the image into CAD, scaling it up to actual size, my very rough
calculations, (which have been comparable in the past to documented events)
shows the following:
The prominence along the edge is ~30,400 miles high.
The active region itself is ~42,000 miles along the long axis.
The outburst reaches approximately the same distance in 3 frames, giving a
duration of .25 hours and a velocity of ~163,000 mph, or about Mach 230. (Mach
number being, of course, irrelevant within the Sun's atmosphere, but you get
the idea.) :-)
These calculations have wide error bars, of course, given the perspective and
foreshortening of the image, but it never ceases to amaze me the actual
magnitude of the numbers involved when dealing with our nearest star. I often
say, if people actually knew what was going on at the Sun's surface at any
given time, most of us would live underground. And this wasn't a particularly
large burst! ;-) Spectacular images, Tom.
Steve Dodder
Coordinator, Grand Canyon Star Party, North Rim
Chairman, SAC Novice Group
Director, Stone Haven Observatory
sdodder@xxxxxxxxxxx
Visit my web site at http://www.stonehavenobservatory.com
> Subject: [AZ-Observing] Re: Another Sun Time-lapse Movie
> From: tjmac@xxxxxxxxxxxxxx
> Date: Wed, 21 Dec 2011 13:05:51 -0700
> To: az-observing@xxxxxxxxxxxxx
>
> I am curious as to what height that new flare reached. I love the way that
> you caught the burst. Base on the usual Earth vs. Sun size comparison, it
> appears to reach 1 to 1.2 Earth diameters in 15 minutes...
>
> Tim
>
> On Dec 21, 2011, at 12:55 PM, Tom Polakis wrote:
>
> > I used a 2.5x Barlow lens in the Pronto with the 60mm H-alpha filter for
> > this sequence. The interval between the 12 frames is 5 minutes, and the 55
> > minutes of activity shows up in a movie that lasts 1.8 seconds. At this
> > level of magnification,the interval should be shortened to about 1 minute.
> > The most interesting feature is just above the overexposed region halfway
> > through the sequence, which takes only 15 minutes to evolve. Velocities
> > must be in the tens of thousands of miles per hour.
> >
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