Sky & Telescope - May 2024 - 65

because I'd never had difficulty finding the star before.
I didn't figure it out until a few months later when I was
observing from home.
I was using my 80-mm scope again. And getting confused
again. So, this time, I also employed my 30-inch. Goodness, I
was starting to doubt I had ever seen Barnard's Star! It wasn't
until I could easily see both flying-geese asterisms at the same
time in my 30-inch at low power that my confusion evaporated.
My observing notes tell the happy tale:
Ok, now I've got it! I had the image scale all wrong at the OSP
in July - the [flying-geese] asterism I was looking for is much
smaller, and in fact . . . is really only about 10% as big! [as
the larger flying-geese asterism]. It certainly mimics its shape
though! Also, I can see Barnard's Star through the 80-mm finder
with the magnification cranked all the way up [40×, with a
zoom eyepiece], but it's faint. Unexpected clouds are getting
in the way at times, so at best, transparency is kinda lousy.
Anyway, all the asterisms I need to locate Barnard's Star are
best seen through the 30-inch at 113× now, and the star itself is
subtly orange-red.
The clouds closed up the sky as I was writing my notes, but
I barely cared because I'd found the source of my confusion
. . . and had definitely seen my star again. Whew!
Waxing Sentimental
Going back in time 40 years and 6.9′ worth of proper motion,
in 1983 I wrote:
Only six light years distant, this inconspicuous little star is the
second closest after the triple Alpha Centauri system - starlight
only six years old, and next to the sun, the youngest starlight
I've ever seen.
POSS1
I've since seen Alpha Centauri, so that statement is no longer
fully true, but I still like its spirit. Young starlight is fairly
unusual and worth seeking out simply for the pleasure of seeing
relatively fresh photons.
But it's more than that with Barnard's Star. I was 27 when
I first observed it, and, so far, I've watched it for nearly 60%
of my life. If I'm fortunate enough to follow it to the top of
the chart in Burnham's Celestial Handbook, I'll have marked
almost three-quarters of my life accompanying a small red
dwarf as it makes its silent way through the Milky Way.
As such, its proper motion has gradually become a meaningful
touchstone. Not only because I've been at it for so
long, but for how I think back nearly six years each time I see
it as well as wonder what circumstances will greet me at the
next observation. (In a way, it's like when I was kid and my
parents would mark my height on the wall in the kitchen to
track how much I was growing, and I'd wonder how tall I'd
end up as an adult.)
More to the point, the process of tracking my little star on
page 1,252 of Burnham's Celestial Handbook Volume Two has
become increasingly precious. My hope is that my experience
will inspire others - you, perhaps - because on a personal
level, there are few projects more satisfying than following
the proper motion of Barnard's Star.
¢ Contributing Editor HOWARD BANICH is a big fan of this
little star. You can reach him at hbanich@gmail.com.
FURTHER MATERIAL: A neat GIF that shows how Barnard's Star
moved between 2007 and 2017 is at https://is.gd/barnard_star_
motion. You'll find a ready-to-print version of the chart on page
63 at https://is.gd/barnard_finder. For E. E. Barnard's original
discovery paper, in which he first describes his eponymous star's
proper motion, go to https://is.gd/barnard_1916.
POSS2
Fun Facts
Barnard's Star rotates once every 145
days or so, which is typical for a red
dwarf of its age of 7 to 10 billion years.
At only 16% of the Sun's mass and 18%
of its radius, it occupies a spot on the
lower end of the main sequence, where
it will stay for several trillion years.
Along with its two-dimensional proper
motion, it's also moving toward us -
and in about 9,800 years will be only
3.75 light-years away.
Proper motion is the apparent movement of a celestial body against the background stars as measured from the
center of mass of the solar system. We can use images from the First Palomar Sky Survey, POSS1, carried out in
the 1950s and its follow-up, POSS2, in the 1980s to highlight Barnard's Star's motion during that time interval. The
images above clearly show how much the position of Barnard's Star changed over 30 years.
sk yand tele scope .o r g * MAY 2024 65
POSS / STSCI / CALTECH / PALOMAR OBSERVATORY

https://www.is.gd/barnard_star_motion https://www.is.gd/barnard_star_motion https://www.is.gd/barnard_finder https://www.is.gd/barnard_1916 http://skyandtelescoper.org

Sky & Telescope - May 2024

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