[APML] Science in Astrophotos?

["siebren klein" <s.s.klein@tue.nl>]

Hello Chuck,

I think science is mostly getting to know what makes things tick.  (There is
of course that exploration part: getting to know what there is) Art is more
about getting people to tick differently. Doesn't that apply to most
pictures in Astrophotography?

Science is not only data taking. Sometimes many data are necessary, and
nowadays, a
correct color picture generally does not tell enough. A red shift, for
instance, can
only be determined by measuring the location of spectral lines. To see how
fast a star turns, you have to measure things about the spectrum lines. To
see how fast it ejects matter...spectra. To see whether a star has
planets...spectra measured over the years, weeks or days.

To learn the velocity distribution in a galaxy, spectra of several spots on
it. A coarse impression by taking a few filtered images won't do. And so on,
and so on.

So there are few pictures in scientific astronomy.
They mostly select a very small region and take spectra. IF they use
pictures, it is only to know what small region they will select to take a
spectrum of.

An exception is perhaps the pictures of gravitational lensing if they use
computers to derive the mass distribution of the lens. As soon as they look
at the lensed galaxies, they put a spectrograph on them.

Many professional astronomers have never seen an object, would not recognize
M42 from a picture or know when to look for it or where. I know some. An
astronomer on Los Muchachos (La Palma) warned me it would not worth while to
visit the observatory as they never looked through the telescopes (which
were pointed for them by technicians) or even photographed a celestial
scene.

There are exceptions, like Halton Arp, but they are not mainstream science.
Arp has been banished from observation time for decennia. Prejudice..?

It is very difficult to do science with chemical photography, as
quantitative results are extremely difficult to get (except for positions of
moving objects, almost exclusively in the solar system). The CCD has
competely taken over, as the results are more easily quantitative.

Science with CCD is possible for amateurs, but generally means making long
series of intensity measurements of variable stars through standard filters.
It never means making nice pictures.

One of my friends who got his PhD shortly after his 50th birthday devoted
years and years to follow minute changes in the polarization of certain
stars preselected on the base of their spectra. After the observatory of his
university was closed down, he built his own observatory to make a longer
series of measurements. As he in financially independant, you could call him
a professional amateur. Even so, he only was thought to be worthy of a PhD
after making a number of calculations on models and comparing them to his
results. Whether this was knowing what makes those stars tick...that's
another question.

But he is an exception. Most science is done in short projects because
proposals are set up to generate results SOON...or your next proposal won't
be financed and you will not get observing time.

Clear skies

Siebren Klein
s.s.klein@tue.nl
http://www.geocities.com/siebren2001/index.html

----- Original Message -----
From: Chuck Vaughn
To: astro-photo@seds.org
Sent: Wednesday, February 13, 2002 7:34 PM
Subject: Re: [APML] Science in Astrophotos


Torsten,

> It takes more than technical perfection to do science. The important (and
> hard) part is to come up with a question (that has not been answered
> already!) that the image can shed light on :)

You bring up some interesting points here so let me ask some more questions.

First, I think it's quite easy to come up with a question that has not been
answered. Let's try one. What would NGC XXXX look like if it could be seen
in color? (For XXXX insert any number for which no color images of any kind
exist.) If an astrophotographer carefully calibrates his system, takes the
images required through a known filter set, creates a color image, and
defines how the data was handled, why would this not be science?

OTOH, if one carefully calibrated his equipment, took photometric data of
SAO XXXXX, and determined the star's magnitude within certain error limits,
why is this science?

Why is the first example not considered science and the second example
considered to be science? I don't see any difference between the two. If
anything the first example makes an effort to answer a question that has
no existing answer. The magnitudes of all SAO stars are known to some
accuracy. Why continue to take photometric data? In the hope of discovering
a previously unknown variable?

Why is photometry elevated to a level above serious astrophotography?

General data taking is a common form of science that doesn't answer any
particular question. Scientific discoveries are made when no question at
all was asked by noticing something in existing data. No question in
particular has to be asked to do science.

I think that dismissing all amateur astrophotography as art is a far too
narrow definition of science.

Chuck <aa6g@aa6g.org>


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