The Washington times. [volume] (Washington [D.C.]) 1902-1939, 1903-08-02
AN EVENING WITH THE STAR-GAZERS
AT THE I. S. NAVAL OBSERVATORY
What the Government Shaps the Hills of Georgetown Doing in
Regard the Borely Come-The Studies Captain Ches-
ter, Prof Dnwidde and Prof Peters

comet several times with his six inch
star camera"
Yes" said Prof. Peters, with
an hours exposure on July % the tail
OF the comet, which was shown to be
double, could be traced to the edge of
the plate or to a distance of nearly
two degrees. 1t is a somewhat difficult
operation TO photograph comet as its
motion through space carries IT rapidly
| across the heavens. 1t is, of course,
| necessary to follow the comet with the
guiding telescope; the stars in the vi
cinity are. therefore, drawn out into
trails
Ihose on the plate OF July % had an
extent of Zoo of an inch, which gives
an apparent motion of about 200 seconds
OF arc per hour for the comet On a
photograph taken July IS the apparent
motion was shown TO be just twice as
great, but the tail was only two de-
grees long.
This is print of one of my mega
tives. 1 exposed the plate an hour and
half" The print shows a blot of
white in a gray field, switch is dotted
with narrow white Sits about a tenth
or an inch long Some are fainter than
others, but all point In the same direc-
ton. These Sits are photographs of
stars and they are given their peculiar
appearance by their motion and the
long exposure of the plate. Prof.
Peters is one of the best astronomical
photographers IN the country. He is
In love with his profession and has
followed it ever since he was very
young.
Seen Through the Glass.
THE comet through telescope" said
Captain Chester. in answer to a quos-
ton, has the appearance Of a small
planetary nucleus, surrounded by a
nebulous envelope. Its tail extends
away from the sun and is about two
degrees long Just now the tail looks
shorter than 1t actually is because it IS
presented obliquely to our view.
I'm a special telescope called a
'comet-seeker, which is used to dis
cover comets. the tail can be followed
for somewhat greater distance, per-
haps l should say two and one-half de-
srees; say FIVE times the diameter of
the moon. The Borelly comet is the
brightest seen here In recent years. 1t
is, IN fact, a star OF about two and
one-hah magnitudes at its brightest.
For the reason that IT is so bright
Washington folks have viewed it on
clear nights through opera and field
glasses.
This diagram viii give you good
idea Of the comets course" said Cap
tain Chester, taking up two pieces OF
cardboard Joined and cut in the shape
of parabola and an ellipse The blunt
nose OF the parabofa. representing the
course OF the comet. intersected the
ellipse, which represented the orbit OF
| the earth.
The comet has been receding from lis
and approaching the SUI ever since July
/ q, the day when it was nearest the
earth. It's least distance from the sun
/ on perihiliOn passage viii be on Au-
gust %. On account of the position of
/ its orbit with respect to the path OF the
earth. or the elliptic. as it is called.
the comet will again approach the
earth after its perihilion, but at that
/ time it will be visible IN the southern
/ heavens only.
Other Weu-Known Comets.
Many of the comets that appear re-
main visible but a short time while
/ they are in the neighborhood of the
earth. Computation shows that in many
instances they are visitors to the solar
system from outer space. IN this case
the orbit is either parabolic or hyper
/ parabolic, and SO the comets can never
return The comet now visible, which
we call Comet c, 1903, probably belongs
| to this class. By the attraction of some
Of the larger planets they are some
! times turned from their course enough
to enable the sun to retain his grasp
place IN the solar system. Such comets
! are known as periodic.
There have been but few bright
comets visible in recent years. The
great comet Of 1882, which appeared IN
! September Of that year. is still remem-
/ bered by many people. 1t was so bright
as to be visible even in the daytime. and
while close to the sun. For many
months it was a conspicuous and beau
! tiful object IN the early morning sky.
Another bright comet was discovered
| in May. 1901. but was visible to observ-
ers in southern ATTITUDES only. 1t was
/ first seen in Australia, but Prof. Din
! widdie here discovered ii independently
at Solok, Sumatra, a few months after
+ ward. Prof. Barnard photographed it.
/ Both these gentlemen were members of
/ the Naval Observatory eclipse expedi
/ tiOn located there.
/ THE degree of brilliancy comet may
assume on approaching the sun can only
/ be predicted theoretically. Some of
( these bodies have been known to in
| crease more rapidly in brightness near
/ perihilion than theory would indicate.
/ Consequently. this present comet Of Bor-
ely may become much brighter"
A Shower of MeteOrs.
eff this comet met the EARTH" said
| Prof. Peters, Il believe the result would
| be a shower of meteors. a marvelously
beautiful spectacle attended by the ig
milton of the meteoric particles compos-
/ ing the body of the comet.