Pittsburg dispatch. [volume] (Pittsburg [Pa.]) 1880-1923, 1889-07-01
AMONG TIE STARS.
The Sun Approaching the Karth-spets on
Old sol-Morning md Evening Stnrs-

Auo sun approaching the 8artn-Spots ou
Old soI-Mornins md Evening stnrs-
Jupiter and His BeIs-Phases Of the
Moon.
WRITTEN FOR THE DIsPArcH.1
Old Sol made rs his longest visits last month,
and he is now moving southwark faster and
faster. his declinarion decreasing from 2S0 0f
to lSo or during this month, while the day
shortens by Al minutes.
To-day the earth Is at that point in her orbit
at which she is farthest from he sun. She Is
nearest about January ], the difference in dis
tance on the two dates being about 8 100000
miles. or one-thirtieth Of the whole distance.
Ii the axis of the earth were perpendicular to
the plane of the orbit, instead of inclined go
~ from the perpendicular, we should have no
seasons on the earth except those due to her
varying distance from the sun, and the minute
changes in the absolute amount of heat the
sun radiates. All over the world It would be a
lew degrees warmer about January than on
July l. As 1t is, the extra heat in January
goes to mitigate the Northern winter and
make the Southern summer hotter; while in
July the Northern summer and the Southern
winter are colder than the corresponding sea-
sons In the other hemisphere
An Unexpected sun Spot.
A large sun-spor, visible in a small telescope,
was reported on the solar disk few days ago.
This is something unusual as the "maximum"
OF sun-spots will not occur till 1893 The num-
Der of spots on the sun is periodically variable,
there being the greatest number every IL years;
midway between these msxims there may be
months without single spot showing itself.
X. A. Declina-
tion. Rises. Transits. Sets.
July s.. n. oom 20 ~ 4:s7 l2:e4 An. Isl 2. M.
July 25 ..sh.2im. 100 sY 5:is 2:2sA.M7:ss PM
Mercury is morning star throughout the
month, and may be seen in the early morning a
above and to the right of the sunrise point.
He reaches his greatest western elongation at
A. M on the 18th, when he is 200 At west Of
the G ssn His apparent diameter on on o this date
The phase is about half moon.
r.. A. Declination. Rises. Transits.
J1y x S @ lo 1go "a "a NORTH north sSs An Sa IN
July .. 7h2lm 70 24 north. 4:os AN. n:H AM.
venus ms n Morning stnr.
Venus is also a morning star, shining un-
rivaled in the eastern sky, and maintaining her
sway until long after the fainter stars have
disappeared before the approach of the rising
sun. She reaches her greatest elongation west,
49, "A. on the 10th, at IA. M On this date she
is 65. 564 900 miles from the earth. The phase is
about halfmoon. The apparent diameter of
Venus decreases during the month from 26"
to 1917.
r. A. Declnation. Rises. Transits.
$aiz s. a. ssm: Iso@ s:esAs n s:li 4 \.
July S..5h .Osm. $50 5y l;59 A. NJ. 9:l4 A. NJ.
Mars is morning star. but still too near the
sun TO be seen As the orbit of Mars lies much
nearer to us than the orbits of any of the other
superior planets, he moves at more nearly
the same speed and has more nearly the
SO that they keep together or separated
for long time, and therefore it will
be many mouths before Mars will be around
diameter is A.. About midnight on the 27th Of
the month Mars and Mercury will be id con-
junction, Mars being 14 north of Mercury.
nssa Jupiter, the prince OF planets. is now at his
southeast, and remains visible all night. He
may easily be recognized low in the southeast
in the earlier part of the evening, or in the
south about midnight, as he is much brighter
than any of the surrounding stars. Although
visible all night he is technically evening star,
because. be having % 9 passed opposition last month,
rent diameter on the 10Th is "A" and his DIS
tance from the earth 394, 900 miles.
Jupiter's JeweIed Belts.
The belts of Jupiter are easily seen with
small telescope when the planet is so well situ-
ated as now The satellites may also be
watched, and with moderate sized telescope
their eclipse in the shadow. of Jupiter, their
occultations or disappearance behind his disk,
and their transits across his disk may be OBJ
served. The eclipses of these satellites fur
nished the first determination of the velocity
of light. The period of rotation about the
planet was accurately known for each of the
four satellites Three of them are eclipsed at
occur at regular intervals, so that, If the time
of one Is observed, the time of any future one
may be easily computed. About the year 1873
the eclipses occurred 11 So" later when Jupiter
was far;hest from the earth than when he was
nearest. The only way to account for this was
that the light occupied the 16 36' in going the
extra distance when Jupiter was farthest
away. This extra distance was twice the
diameter of the earths orbit, or about 1S5. .00O.-
COO miles. Dividing this distance by the num-
Der of seconds delay, we get Is5, 100 miles as
the velocity OF light per Second. The velocity
has since been determined in several other
ways. and this result shown to be correct.
A little careful watching and patience will
enable the amateur with moderately good
telescope to see some of the eclipses and occul-
tations If a satellite is noticed near the planet
1t should be watched to see If 1t Is approaching
or receding: if approaching. it will disappear
behind the planets disk, afterward to come
out of the shadow on the other side little dis
tance from the disk.
K A. Declination. Rises. Transits.
duly 5 .lSh osm 2So lS south $50 Pm. I:sl Pm.
July l5..lsh Ohm So W south. 6:lC Pm. 10:E Pm.
July 25..l7h som. go zT SOUTH 5:26 Pm. lO:O3 M.
Saturn and Uranus.
Saturn is still evening star, but has gotten
too near the sun to be well seen.
Uranus Is evening star and is in quadrature
with the sun on the Sth, which means that he
300 east Of the sun. He is scarcely visible to
the unaided eye, but may be found between the
first magnitude star Spica and Theta Virginis,a
star a few degrees northwest of Spica. He is
about one-sixth of the way from Theta to |
Spica.
X. A. Declination. Transits. Sets.
July 13h. O7m. 50 2S south. $3.50 NJ. I2,lI
July IS. ,13h 0sm 50 81 SOUTH 5:5l p. NJ. 1I:S2
July 25.....ish. Osn. 90 s6 south. SAB P. M. 1854
Neptune is morning star, rising two or three |
hours before the sun. He may be found about |
50 south of the Pleiades.