Burlington weekly free press. [volume] (Burlington, Vt.) 1866-1928, 1912-05-09
THE MAY SKIES.
Jupiter the brightest Among the Plan
ets--Two Full Moons This Month.

evening sky this month Is the coming of
the planet Jupiter into a position where
1t can be observed at convenient hours.
Since 1t was conspicuous in the early
morning last January in company with
Venus, 1t has been rising earlier, as the
nights have followed each other until
now as the month begins it rises at 9:2o
p. m. and will rise at sunset at the close
OF the month. The planet Is far south in
the constellation Saeittarius, and is NOV
Ing westward towards the red star An
tares In the adjoining constellation Scor-
pho. 1t rises in the southeast, and as it
moves across the sky each night de-
scribes the path which the sun takes in
the latter part of November. 1t is the
most brilliant star now to be seen in the
sky, as IT'S only rival Venus is not in
evidence.
The telescope view of Jupiter Is al
ways interesting as the belts crossing
the disc and the four bright satellites in
their ever-ohanging positions are always
prominent features. There are several
evenings this month in which transits of
the satellites and their shadows may be
seen. On the End after 10 p. m. and the
18th after $3.50 p. m. satellite I and Its
II p. m. and the 3lst after p m. satellite
II and It's shadow cross the disc. On the
9th the shadow OF satellite III is in tran
sit as the planet rises. 1t leaves the disc
soon after $3.50 D. M, eight minutes before
the satellite itself begins It's transit.
After Ills on the same evening satellite
preceded by It's shadow crosses the disc.
On the 22nd, satellite II Is eclipsed, the
tp.Dn
Jupiter Is not only the brightest planet
visible but It Is the only one at all con-
spicuous. Mars Is still in the evening
sky, but not as bright as Pollux, near
which it Is passing. The planet moves
this month from Geminl into Cancer. on
the goth 1t is In line with Castor and Pol
lux, the southernmost of the three. Its
rudy color distinguishes it from other
stars in its vicinity. and It is now quite
far distant from Aldebaran. the star In
the western sky, which resembles 1t most
closely. It sets before midnight. st II
o'clock on the last OF the month
The telescope planet Neptune Is In ex-
cellent position for evening observation
with a suitable instrument, which should
be pointed to Right Ascension III. 32m..
declinaton n 81 degrees IA minutes. This
is in Gemini, near Mars. On the 18th
Mars passes Neptune. going degrees
farther north.
Saturn Is invisible this month, as 1t IS
near the sun in direction. on the 14th 1t
passes behind the sun. and after that
date rises before the sun. on the 9th 1t
Is near Venus, both planets in the strong
twilight of the early morning.
Venus can be seen with difficulty, ris-
ing on the 1st at 4:O5 a. m. and on the
| 3lst at 3:45 a. m. The twilight half an
hour before sunrise is too strong for
even this brilliant planet. Not only is 1t
near the sun in direction, but it is be-
| You'd the sun in distance, and. therefore,
! near it's least brightness
! Mercury may be seen before sunrise for
few mornings near the 18th. 1t is of
| about one-half its greatest brilliancy. 1t
rises on the 18th at $40 a. m. 45 minutes
before the sun. 1t may be seen at about
| 4 a. III. above the eastern point of the
horizon. but will be found with difficulty
unless a field glass or telescope Is used.
| Uranus rises on the lst at 12l5 a. m.
and on the 31st at 1O:45 a. m. 1t is low in
the south in the constellation Capri
| cornus. On the Sth 1t begins its retro
grade motion among the stars, which an
nounces the time 1t car be best examined
| with a telescope.
The Moon this month is full on the LIST.
new on the 18th and again full on the
3lst The latter half of the month has
moonIit evenings. The Moon passes near
Jupiter on the 8rd and again on the Soth,
and is near Mars on the Goth. 1t is low
| In the south on the 9Th and high in the
north on the 18th.
The progress of the seasons each year
Is marked by the consultations which
move steadily westward as the nights
| follow each other In May, the bright
winter groups disappear in the west. and
we see for the last time Taurus and
| its subordinate groups. the Pleiades and
| Hyades, and Its rudy star Aldebaran;
| CAMS Major with the brilliant dog star
Sirius; Orion with its belt and Sword and
| its bright stars Betelgeuse and Rigel
| Genlini with Its twin stars Castor and
Pollux and Auy1ga with Its brilliant star
Capella are approaching the western hori
ION. To take the places OF these groups
Leo. Virgo and Libra continue the zodi
acal line with Regulus and Spica the
most conspicuous stars. High in the
|
ing star. while Lyra in the northeast Is
marked by the star Vega In the south
east is the quadrilateral Corvus ant
! Hercules. Ophicuchus. Serpens Coma
| Berenices and Corona Boroalis are in the
east The northern heavens show the
| Great Dpper high In the sky, Cassiopela
near the horizon and Draco in the east.
1t Is often interesting to those who are
watching the advance of our knowledge
OF the heavenly bodies to discover tha
certain studies are halted for the time
waiting for further advance in other re
searches with which they are related
subject of the individual motions of TIL,
distant stars. They are called fixed
! stars" but are really moving; II Is onl,
their enormous distances which make
them appear to lis to be fixed with REGARD
to each other. The problem is to find on
| the direction In which each Is MOVING
and its rate of speed. The first and sim
plest way is to determine the exact di
| rection of a star at two times many
years apart; this shows at once whethe
| the direction from the earth is chang
| ing, and the amount of the change. Tn
| longer the interval the smaller tn,
| change that can be detected. II the in
terval is as much as a century change
as small as a hundredth OF n second car
be thus discovered Several Thousand
| stars have movements of this amount
Now the investigation halts because sta
catalogues enumerate only very small
number of the stars visible in the sky