Sky & Telescope - March 2023 - 57

Pro-Am Conjunction by Diana Hannikainen
Star Notes
Join a project dedicated to
preserving logbooks of yore.
F
or most of astronomy's history,
observers recorded what they saw
at the eyepiece by jotting down notes,
sketching, or both. These methods can
be subjective, leading to eclectic interpretations
of the science of the skies. But
they nevertheless afforded us the only
view of the universe until the early 19th
century, when a new, more accurate
technique of recording celestial phenomena
arrived on the scene: photography.
Glass plates and women computers.
By the time Edward Charles
Pickering became the fourth director of
Harvard College Observatory (HCO) in
1877, astronomical photography with
the famed 15-inch Great Refractor had
practically become routine. Pickering
launched ambitious projects dedicated
to observing the sky, both photometrically
and spectroscopically. So ambitious
was he, in fact, that he established
an observatory in Arequipa, Peru, to
cover the Southern Hemisphere sky.
Soon, Pickering and his staff were inundated
with photographic glass plates . . .
and valuable astronomical data. And
so he started hiring assistants to curate
the overflowing glass-plate collection -
and for that he turned to women.
The Harvard Computers (as they
came to be known) did so much more,
though. Pickering's Scottish housemaid,
Williamina Fleming - whom he later
nominated to be the HCO's first Curator
of Astronomical Photographs - discovered
the Horsehead Nebula, and her
name lives on in a wisp of the Cygnus
Loop (S&T: Sept. 2021, p. 30). We owe
our current method of stellar classification
to Annie Jump Cannon, who also
identified more than 300 variable stars.
Henrietta Swan Leavitt formulated the
Cepheid period-luminosity relationship
(S&T: Dec. 2021, p. 12), while Cecilia
Payne-Gaposchkin deciphered the
chemical composition of stars.
These four are the Computers you've
most likely heard of. Countless others
who contributed to our fundamental
understanding of the universe have
largely gone unrecognized. But existing
endeavors aim to rectify this.
DASCH it all. By the late 1980s,
HCO had amassed more than half a
million photographic glass plates - the
world's largest collection. The vitreous
surfaces aren't only peppered with the
dots and splotches of stars, nebulae, and
galaxies, but also the meticulous notes,
musings, and calculations of the women
who analyzed them. To preserve this
precious material, the Digital Access
to a Sky Century at Harvard (DASCH)
project is digitizing the glass plates for
posterity. In addition, the century-plus
of data allows for the systematic study
of variability in myriad objects on time
scales ranging from days to decades.
But there's a second, priceless piece to
the collection: the Computers' logbooks.
Plans to preserve. The entity that
houses the glass plates, the Wolbach
Library, launched Project PHAEDRA
(Preserving Harvard's Early Data and
Research in Astronomy) to collate
and conserve the valuable information
contained in the Harvard Computers'
notebooks. One component
pINSPIRATION FOR ALL Volunteers are
helping preserve some 2,500 notebooks that
Harvard astronomers, including the Computers,
kept between 1750 and 1990.
of this project is Star Notes. Phase 1
(completed) identified plate numbers
in the logbooks, which link them to
the digitized DASCH material. Phase 2
(currently underway) aims to catalog
elements that are non-textual, such
as sketches and hand-drawn diagrams
and charts. Besides the Computers'
logbooks, volunteers will also scour
material from before the photographic
era, dating back to 1750 or so. Says Nico
Carver, Wolbach's Librarian for Collaborative
Programs, " This phase is akin to
a scavenger hunt, as most pages do not
have sketches, but it is exciting to find
them when they pop up! "
You'll need nothing more than a
dash of historical curiosity and an
internet connection to participate.
Head over to https://is.gd/star_notes
and study the tutorial for guidelines.
" Volunteers can expect to help us better
understand what is hidden within these
valuable notebooks, " says Carver. " For
those who want to dig deeper, we can
connect them to resources and support
their research. " Should your fingers be
itchy, you can also partake in Project
PHAEDRA's transcription endeavor
(https://is.gd/phaedra_transcription).
By participating, you'll not only directly
commune with the history of astronomy,
but you'll also preserve the legacy
of hundreds of hardworking, largely
forgotten astronomers.
¢ DIANA HANNIKAINEN is grateful that
the hard work of the women astronomers
of the 1800s is being preserved.
sk yand tele scope .o r g * MARCH 2023 57
HARVARD LIBRARY ARCHIVES / PUBLIC DOMAIN
https://is.gd/star_notes https://is.gd/phaedra_transcription
Sky & Telescope - March 2023

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