Archived posting to the Leica Users Group, 1999/04/04

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Subject: Re: [Leica] landscape photography - off off topic
From: Dennis Painter <dpainter@bigfoot.com>
Date: Sun, 04 Apr 1999 20:09:09 -0700

Alex,

It's possible. Old telephoto lenses can be used with CCD's to view
celestial objects.  For more info on building your very own CCD camera
try here:

http://www.wvi.com/~rberry/cookbook.htm

I am posting all of Alex's message since you may need it to understand
my reply.

Dennis



Alex Brattell wrote:
> 
> So hard to tell if something's an April Fools joke nowadays.
> Thought this might inspire anyone who's getting bored photographing the
> neighbourhood, and it's something to do with those Japanese
> lenses..................
> 
> (via American Astronomical Society)
> 
>         ANN ARBOR---A low-cost, automated telescope built from recycled
> lenses and hardware is giving scientists important new information about
> gamma ray bursts---brief emissions of high-energy photons traveling to
> Earth from violent explosions in the deepest reaches of space.
>         Astronomers from the University of Michigan and the Department of
> Energy's Los Alamos and Livermore National Laboratories will describe
> these new details---including their measurements of the brightest optical
> celestial object ever recorded---in the April 1 issue of the science
> journal Nature.
>         The Nature paper presents analyses of measurements from a gamma
> ray burst observed Jan. 23 by a telescope called ROTSE-1, for Robotic
> Optical Transient Search Experiment.  ROTSE-1, responding to a detection
> signaled by NASA's Compton Gamma Ray Observatory, captured optical
> emissions from the burst while the gamma rays were still arriving---the
> first time such an observation has ever been made---and recorded the burst
> while the optical emission was still peaking.  Previous detections of the
> optical counterparts of gamma ray bursts have caught only the faint, fading
> afterglow of the event.
>         "It's like the difference between watching two cars collide and
> coming on the accident scene several hours later," said Carl Akerlof, U-M
> professor of physics.  "In the first case, you have a much better chance
> of understanding what caused the crash."
>         ROTSE-1 uses four 35-mm telephoto lenses "of a variety favored by
> paparazzi for photographing elusive subjects under dim light conditions,"
> Akerlof said.  The 4-inch-diameter lenses are connected to charge-coupled
> devices---basically the same technology found in digital cameras now on
> the consumer market.  To reduce costs, ROTSE's components were gathered
> from junk yards, used-camera shops and the amateur astronomy market.
>         The four cameras, strapped to a single mount, point to slightly
> different, but overlapping, sections of the sky.  Together they capture
> 250 square degrees of the sky at once, about what would be covered by a
> dinner plate held at arm's length.  Under computer control, ROTSE-1
> automatically scans from horizon to horizon, taking a series of short
> exposures that together cover the entire visible night sky.  In clear
> weather, ROTSE can compile a complete sky record twice each night.  But
> the telescope also is designed to respond immediately to unexpected events
> flaring in the night sky.
>         On Jan. 23, ROTSE-1 interrupted its normal sky search after the
> orbiting Compton Gamma Ray Observatory spotted a powerful emission of
> gamma rays, triggering an automated alert network.  Ten seconds after the
> CGRO detection, ROTSE-1 aimed itself at the estimated location of the
> outburst and recorded a series of seven images over 10
> minutes, beginning 22 seconds after the initial detection of gamma rays.
>         Akerlof and his colleagues used a precise location provided by the
> European satellite Beppo-Sax to locate the optical transient in their
> images.  After a short time the team was able to reject other possible
> sources for the signal, such as flare stars, meteors or Earth-orbiting
> satellites.  After completing this analysis, the team broadcast a
> worldwide announcement via the Internet.
>         From ROTSE-1's first exposure to the second, the optical
> brightness increased about 16-fold.  At its peak brightness the object,
> estimated to be 9 billion light-years from Earth, was about 6 million
> times brighter than a typical supernova---an exploding star that can by
> itself briefly outshine an entire galaxy.
>         The ROTSE-1 observation represents the most luminous optical
> object ever detected. "If you had been gazing at that spot with
> binoculars, you would have seen a 'star' appear, brighten, and fade within
> minutes, an unbelievably violent event from the very edge of our
> universe," said Galen Gisler, an astrophysicist at Los Alamos National
> Laboratory.
>                                        # # # # # #

- -- 
Experience is a tough teacher. It gives the test before the lesson.
- -unknown

http://users.deltanet.com/users/dwp/