Sky & Telescope - January 2021 - 57

Pro-Am Conjunction by Diana Hannikainen

W At the AAVSO's annual meeting held in November 1918, Annie Jump Cannon, Henrietta
S. Leavitt, and Edward C. Pickering (clustered
in the second and third rows at center) were
among those in attendance.

A Century and Counting
of Variable Stars
Have a hankering to get involved in research? Join the AAVSO.

A AVSO

undreds of years ago, the line
between professional and amateur
astronomers was fuzzy. Think of the
great William Herschel. A musician and
composer by training, he became fascinated with astronomy, built telescopes,
and made discoveries still discussed
today (such as the planet Uranus).
By the 1800s, growing demand for
larger, more costly light-collecting mirrors went hand in hand with an increasingly rareﬁed environment of participation. Astronomy began closing itself off
from those outside of professional circles
- a trend compounded in the 20th
century with the advent of satellites and
ever-larger telescopes atop mountains.
Professionals largely work in academia,
while amateurs peer at the heavens from
their backyards. Rarely the twain meet.
However, some astronomers on both
sides work to bridge this gap. These
intrepid individuals and organizations
think that pros and ams have a lot to
offer each other. In this new bimonthly
column, we'll explore many kinds of
pro-am collaborations. We hope that
their examples will inspire you to join
in - because science at its heart is DIY.
Our First Guest: the AAVSO. By the
second half of the 19th century, pros had

trouble keeping up with the data streaming in due to newly developed observing
techniques, such as photography and
spectroscopy. Institutes increasingly
relied on the amateur community for
observations of variable stars. Answering
a call in the August 1911 issue of Popular
Astronomy entitled "What an Amateur
Can Do," lawyer and amateur astronomer William Tyler Olcott founded the
American Association of Variable Star
Observers (AAVSO) in November that
year - and it's still going strong today.
AAVSO's mission is to "enable
anyone, anywhere, to participate in
scientiﬁc discovery through variable star
astronomy." Its primary treasure is a
vast database of long-term light curves,
which trace the brightening and fading
of various variable stars back more than
a century. Amateurs provide the majority of these data. Knowing the long-term
variability of stars enables astronomers
to put episodic patterns or snapshot
observations into larger context. Long
baselines are also essential for making
predictions of interesting behaviors.
The professional-amateur interface. Pros nowadays are stretched too
thin between too many specialized
projects and scrabbling over dwindling

resources. Those shiny behemoths atop
mountains? Many researchers only get a
few hours total of observing time. Luckier ones might get a couple of nights.
Hence, professional analyses are often
based on a smattering of datapoints,
which can lead to ambiguity. But the
universe is dynamic. The only way we'll
catch its surprises is with programs such
as those championed by the AAVSO.
Also, since there are only so many
nights per year, and so many projects to
fulﬁll, the large telescopes are mainly
reserved for cutting-edge science, pushing the envelope on faint and distant
targets. In this competition, brighter
sources can lose out. When Betelgeuse
curiously dimmed at the end of 2019,
AAVSO provided the crucial photometry.
What can you do? If you'd like to
participate in this august body's valuable mission, go to aavso.org and sign
up. You can request a mentor who'll
shepherd you in your ﬁrst forays into
the wonderful world of variable star
observing. The AAVSO, via its helpful
staff, provides rigorous training.
Depending on your interests, skills,
and equipment, you can participate
in a variety of programs through the
AAVSO's observing sections, which
include eclipsing binaries (e.g., Algol),
long-period variables (e.g., Mira), and
even exoplanets. Interested in spectroscopy? You can get involved in that, too.
You don't have to make the connection with pros on your own - AAVSO
staff will act as liaison. Amateurs now
work with international researchers
across the globe and, increasingly, participate in data analysis. "The non-professional community are essential collaborators for the acquisition of data,"
says Stella Kafka, executive director of
the AAVSO. "Amateurs enable research."
The line between pro and am astronomers is again happily fuzzy.
Observing Editor DIANA HANNIKAINEN
works on both sides of the pro-am line.
sk yandtelescope.org * JANUARY 2 021

http://www.aavso.org http://www.skyandtelescope.org

Sky & Telescope - January 2021

Table of Contents for the Digital Edition of Sky & Telescope - January 2021