Pittsburg dispatch. [volume] (Pittsburg [Pa.]) 1880-1923, 1889-05-02
THE MAY HEAVENS.
The Days Grow Longer-Facrs Abour Mer-
cury-JuDIter an Interesting Objecf-ln-
feresting Information for Star Gazers.

cury-Jupiter an Interesting Object-In-
teresring Information for Star Gazers.
WRITTEN FOR THE DrsPATcH.l
The sun continues travelling northward, and
the day grows in length by SO minutes during
the month of May. On the 9TH the suns apparent
diameter is 81 49,, and his distance from the
earth 9S, 100000 miles; on the 25th his diameter
is 81 80" and his distance ~, 900. 900 miles.
r. A.. Declination. Rises. Sets.
May 5..Zh SIM. 16o 2T north. 5:l5 A. NJ I:dsP. a.
May May s sm 59o 59o S S north north sGS A. NJ
Mercury is evening star throughout the
month, and gets into very good position for OBJ
| servaTion toward the latter part He attains
his greatest elongation east DO 49f, on the 4th;
1. e., on that day he is farthest east from the
sun, and sets the longest time after him. This
viii therefore be the best time for the amateur
| to try to catch sight of his little disk. The
! planet can only be seen with the unaided eye
under certain favorable conditions which do
| not always occur; moreover, the observer must
have an unobstructed horizon and a
very clear clear sky; In England En- L1 Mercury lis is
| climate. The best time to see Mercury is
| of course when he is brightest and sets
| the longest time after the sun, that it may
| be as dark as po ssible and the planet may be
high above the horizon Unfortunately. these
conditions cam OF be filed at the same time.
The planet is brightest when nearly full, but
when farthest from the sun the phase is about
half moon.
The length of time that the planet sets after
the sun depends on its distance east or west Of
the sun and its northern declination. Now it
happens that at some ''elongations" Mercury
reaches greater distance from the sun than
at others, the maximum distance Deing about
2So and tn minimum 1So but when he reaches
his greatest distance he is always south, while
at some elongations when the eastern or west
ern distance is not so great, he is much
nth 49, Al H.
clination has greater effect on the time the
planet Is above the horizon than few degrees
more or less in the distance east or west. This
Of tbs az sn 2d VIII be % ~ Si east
tne conditions, therefore, being quite favor
able, since he will set about two hours
hit after ,-aaeo. the sun; As the planet reaches
tne month, he may be well seen
few days before the elongation. 1t
is somewhat difficult to catch the little
twlnkler, especially if his position is not known
precisely, but when once sighted it is easy to
keep him in view. An opera or field-glass Will
greatly assist in the search. The following
positions should aid in finding the planet. On
the 10th, at 7:45 P. M, Mercury will be 800 4V
above the horizon and 90 or north of due
west; on the 24th. at the same hour, he will be
lo' W. above the horizon and 1So 1y north of
due west His apparent diameter is Y.3 on
the 9th and S".2 on the 25th.
r. A. Declination. Transits. Sets.
MAY MAY S..'Sh Ssm. @ go 5 sg north 1:d M. S:M
May Is. .5h 4sm $50 49, north. 1:54 P. M. 9:S5 M
Venus has left the evening skies, but will soon
reappear as morning star on. the other side of
the sun with all her former beauty. Her 'in-
ferior conjunction" as the passage of the planet
between the sun and earth is called, took place
on the Both of April The swiftly moving
planet will soon get beyond the beams of Old
Sol, and may be seen in the early morning. She |
grows brighter and brighter during the month,
as the crescent phase gets broader and broader,
though the apparent diameter of the planet de:
creases somewhat On the 9Th the diameter of
the disk is 5S".S, and on the 18th 4".4
r. A. Declination. Rises. Transfts
May 5. .2h. Ism. 10 3U north 4:7 Am. 1143 AM.
May 25 .2h. 04m. ITO 5S north 3s25 M. 1910 AM.
Mars is still evening star, but far away, and
sets too soon after the sun to be seen He is in |
conjunction with Mercury on the 5th, being |
10 0y south of Mercury. his apparent diameter
is 40
Jupiter is now very interesting object. He |
is still morning star, as he will not reach oppo-
sition until the latter part of June, but he rises
before midnight, and is high enough to be well |
seen two or three hours after rising, He is in |
the constellation Sagittarius. and will remain |
in about the same position throughout the |
month. A line from the Pole star through |
Vega and extending as much farther will about |
find him. There should be difficulty in
identifying the planet, as he is much brighter
than any of the surrounding stars.
The chief interest attaching to Jupiter for
obs ervers with small telescopes is his retinue
of satellites. These four bodies visible
have been seen with the unaided eye by some
people possessed of extraordinary good eye
sight In small instruments they appear like
stars, but in larger ones, and with high magni-
flying powers, they are seen,to have disks the
same as the planets and, in fact. they may be
considered planets themselves, of second or
Io- kAa-s N1nA 1oNSN g.
Jupiter does to the sun. These moons re-
volve around Jupiter in much less time
than 1t takes our moon to get around the earth;
the innermost. called by astronomers No. for
convenience, performs his revolution in l day,
Is hours; No. takes 3 days, IL hours;
No. 3, 7 days, hours, and No. A, Is
days. 1S hours Each of the three inner
satellites every revolution passes into the
shadow Jupiter casts behind him tmakIng an
eclipse) passes behind the disk of the planet
loccultationl, and passes in front of the planet
(transit) so that they furnish great deal to
interest an observer. The fourth satellite land
at some seasons the third) on account of his
large orbit, passes above or below the disk in
stead of making an eclipse or transit. OF
course, only few of all the phenomena are
visible at any one place, but by careful watch
ing the observer may catch great many of
to note the position of any satellite which is
near the planet notice if it is going in the right
direction, and how fast and wait
The apparent diameter of Jupiter on the 5th
of the month is,41o; on the 18th, 4So p.
R.A. Declination. Transits. Rises.
May .1sh. S5m 22o & ~ south 4:C2 An. 1l:2S P.M
May 25. ish. som. 23o 0Y south. 2:38 AM. s:59 PM
Saturn is in quadrature with the sun, /. e.,
300 east Of him, on the Sd Of the month, and can
only be well seen in the evening for about two
months more. The plane of the rings is in
clined about 16o to the line of sight, and they
can still be well seen, but at succeeding opposi-
tion the inclination will be less and less. The
apparent diameter of Saturn is 17'.2 on the 9th
and 1874 on the 25th.
r. A. Decination. Sets. Rises.
May g.. Sh.05m. 10 10 e. g. north. la AN. 6:9I Pm
May May r. o T | 81 north north S Ss
Uranus is evening star, having passed oppos-
tion to the sun last month. He may be seen
with small telescope if mounted with circles
in order to point it to the proper place. His
apparent diameter is 31S
May 5.. .1Sh. lin. 6o 4s' south. 10:S1 P. M.
May lsh lsh osm Ss 90 80 49, 81 south south S:5s P N.
Neptune is in conjunction with the sun on
the I'D, and therefore invisible throughout the
month.
The moon presents the following phases this
month:
First quarter. May g. 1900 NJ.
Full moon. Is, 12:00 NJ.
Last quarter. May % 300 A. NJ.
New moon. May 49, 1000 P. M.
The moon is farthest from the earth on the
ith, at A. M when her apparent diameter is
2@ 8l"; nearest on the 18th, at noon, when her
apparent diameter is S3' 22i; farthest again on
The 3lst, at 10 P. NJ, her apparent diameter
then being 29 28"
The moon IS in conjunction with Neptune ON
the lst, az 240 p NJ. Neptune being 10 81 north:
with Saturn on the 7th, at P. M, Saturn being
10 28 south; with Uranus on the 18th, at OILS
P. NJ, Uranus being 40 81 south; with Jupiter
IN the 18th, at 10 P. NJ. Jupiter being IH south;
with Venus on the 18th, at 1922 A. M, Venus {
being 20 2g north; with Mars on the 29th at IL q
P. M, Mars being 80 0Y north: with Mercury on
'he 3lst., at l1l4 A. NJ, Mercury being 10 5S'
north. B. E. LUTY.