The family portrait made by
Nadar
of the founding fathers
Dear visitor,
If you are interested in the history of this All-Sky project
of the paleozoic days, you may well
try to
identify the former
colleagues
who
are still remembered (check for
Kapteyn ,
Russell ,
Henry bros.,
Donner ,
Wof-Rayet ,
Tisserand ,
Gill ,
Loewy still
honored
and
respected ,...)
Women are absent from the group picture but were duly working
on the
survey . Quite a
character
was
Dorothea Klumpke who published the
Atlas
of her husband
Isaac Roberts (number 23 on Nadar's group picture), at the forefront of the
photography of
Herschel's fields
like
Pleiades ,
Horsehead . These first epoch observations
were used to look for changes like in
NGC 2261 .
Dorothea Klumpke was heading for a while at Paris Observatory
a team of clerks to reduce the photographic data.
Please, take a look at this
group of underpaid and dedicated servants, sitting in front of the building of the astrographic instrument: Dorothea is checking carefully the
long list of hand written computations at an
approximate rate of 30 000 stars per year.
(copyright from Paris Observatory)
Dorothea's sister, Anna Elizabeth, was
Rosa Bonheur's
companion and inherited from her
this place close to Fontainebleau, near Paris, with
Rosa's paintings
as well.
The goals and objectives of our former colleagues
were to map the heavens of the faint stars down to apparent magnitude
14.5
thanks to the improvement made by
Draper on
photography,
like we now
map the
Milky Way on the entire electromagnetic
spectrum . Goals and
objectives of present Epoch surveys,like
LSST or
SkyMapper
show how we increased our view of the universe since the Neandertal era of photography.
The first Epoch of the 100-yr old plates
can be used to determine the total
proper motion
component and to derive
RPM diagrams.
It is then possible to estimate
transverse velocity that will
affect stellar motion quite detectable
as function of the trigonometric
parallax . In some sense, a classification based on color index
and proper motion can segregate giants from dwarfs
in a HRD .The
photometric variability can explore different
pulsations
and
modes .
Ernest Mouchez was
very instrumental in organizing the 1887 congress and
was supported by
Victor Duruy
who was very eager to
show
that the french 3rd Republic succeeding to the french 2nd Empire could
take a leadership in scientific progress.
The
value of the astrographic survey was discarded by the generation
of french astronomers who survived WWI as shown in this
figure : the distribution
of the CdC plates of the french zones
(Paris, Toulouse, Bordeaux and Algiers) as function of the
Epoch of observations and the magnitude limit
proves that the interest was fading after 1918.
If you can afford it, you may well own early photographs made by
Mouchez and
the Henrys .
Other photographic
archives from the past are still
around
and digitized . Please, have a look at the
Harvard's cosmos story published in the NY Times of July 10, 2007
and telling the
DASCH effort.
Not all observatories involved in the All-Sky project of 1887
could
survive, example:
Hyderabad . Other
observatories, involved right from the beginning of the project,
kept an interest in this heritage from
the past, example :
Bordeaux .
Henri Mineur was the very first french astronomer
to care around the 1930s about the scientific use of
the astrographic observations in order to give a model
of the Galaxy, to establish a
polar
photometric sequence and
to work on
selected areas . He recognized that the factory-type of work
was preventing any initiative for lofty research
and succeeded to get a quite different
environment for astrophysics in France.