New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1869-04-19
THE SPOTS ON THE Sun.

upon the solar disk large group of spots, VlsiDle
without magnifying power requiring only the pro,
lection of the eye by piece OF colored OF Snokeu
glass. 1t made its appearance upon the eastern eugo
of the sun about week ago, but was theh 700 luuc
foresbortencd from its position TO be conspicuous
Nlr. David Trowbridge writes us that upon the I5th
instant "yhen examined with the telescope 1t was
found 70 consist OF five distinct nuclei, all included
IN one nenunlbra The diameter of the spot in the
Io,oest direction though somewhat fOreshOrtened,
oconpied as much rs one-sixteenth of q solar
diameter or length of about $1,000 miles, and the
breadth was as much as 5000 miles giving super
fetal area of Iabout 100000. square miles, The
diameter of the largest nucleus was about 1000
miles and its area some 100000 square miles, or
moreD At that time the spot had advanced about
one-third of the distance across from the eastern
margin 1t is now little past the center OF Its tran
sit, and will be visible but few days longer, before
the suns revolution upon its axis will have carried
around TO the further side and therefore ont OF our
Wow 1t is not impossible that it maycOntinue upon
the suns disk until after the 9th Of May, in which
case it will again be visible upon the eastern edge
Spots sometime remain upon the disk for many
revolutions. For instance, in 1779 SPOT continued
visible for six months; aud IN 1910 and 1911
Schwabe observed IS returns though not consecu-
tive. of the same group. There are indications,
however, that in this case the spots will have
little permanence; for they have been sOdvded and
separated that yesterday the largest of them was
much smaller than, as measured by our correspond
emit three days before.
Spots upon tho SUM- visible by telescope aid are of
so frequent occurrence that il Is generally the case
tat they are more or less upon the side toward the
earth 1t his been discovered, however, that, as in
the case of the November meteors, there is periodi
city in regard to their number and size. The maxi
num- which occurs at intervals of a little more than
IL years, viii next year; so that We may now
expect for two years to come that the suns surface
will seldom be free from spots and that
there will frequently DO spots or groups OF
spots of large extent and possibly much
larger than those now visible. The nucleus
frequently suIpasseS the earth in magnitude,
and the penumbra has been observed of very much
larger dimensions. Groups of spots have been seen
to extend fourth, third, across the disk.
II is not to be confidently expected however, that
we shall soon witness such phenomenon; for the
maximum itself is subject 10 another period OF about
SO years so that although the spots viii be more FIRE
uuent and larger for the next two years than fOr the
last nine or the nine following 1871 it will not be
until about the year 1892 that the highest maximum
will DO reached.
The cause of the spots upon the sun is not get
known, although its periOdclty seems TO connect 1t
with the larger planets Jupiter and Saturn. 1t has
been supposed that when the sun or part of the
solar surface approaches a planet the spots
disappear or tho brightness Increases Not
only does this period correspond in
remarkable manner with the revolution
of the planets around the sun. and especially of
Jupiter the largest of them but it has been observed
that the period corresponds to that of the recurrence
of neteorc showers. 1t has long been supposed and
two or three years ago was established, that the
November meteoric shower occurred at its maximum
atintervals Of % years. corresponding TO three cycles
of the solar spots, so that the minimum OF spot
freauency comedies remarkably" as Schwabe bin
self has recently remarked, with the recurrence Ut
meteoric showers The phenomenon o. Tic Aurora
Borealis, which was so marked on Thursday evening
last, seems also TO he connected in some way with
the solar spots. 1t will be remembered by many that
an 1859 the very year of the last maximum OF the
solar spots there was brilliant display OF
tho Aurora Borealis. forming corona as on
Thursday last, and visible throughout the Unitod
States When 80 many and apparently so independ-
ert phenomena are found to be connected, the result
can hardly fail TO be the discovery Of the law gov
erping them all and the cause Of That connection.
Lieut. Ashe, the Director Of the Quebec Obserya-
tory, has proposed the following theory: he con
ceyes the suns surface to be composed of an equally
bright and neandescent photoSphefe; that our sun
isa pebrlons star and that the nebula consists in
what is seen as the zodical light, thus connecting
still another apparently independent phenomenon
with the Others and that the solar spots are small
meteor planets that reyOlve around the sun and fall
into it.
Looking at the sun through the telescope, there
are several species of variation from an even lum-
nous surface. First, apparently black spots.
7 saw apparently" because it has long been sus-
81. ~. rn{r lN
selves but only by contrast. In fact, recent OBJ
server has stated that upon narrowing the field Of
view. 80 that q spot could be 10y itself, it was
fouud 10 be OF deep red color. Around the spots
there is usually much larger portion of the disc,
sometimes inclosing two or more spots, called the
nenunibra. This is decidedly selflumlnous, although
much less bright than the general disk ofthe SUM- In
addition TO these there are what are called Jacad',
OF bright streaks which manifestly brighter than
the general disk They as variable rs the spots,
and probably depend upon them, surrounding them
usually near the limb. These have been
proved TO consist Of elevations or ridges III the
pbotosphere or luminous surface Of the sun; and 1t
has been supposed that they sometimes rise so high
as to form the red prOminences visible IN total solar
eelipses and which are now undergoing special OBJ
seryation by recently-dscovered method founded
mon spectral analysis. by which they may be OBJ
served without the necessity for total eclipse TO re-
veal them. In this direction, therefore, we may eX-
meet at no distant day, further and more definite
knowledee of the constitution Of the suns surface.
Observing the suns disk with good telescope, the
attentive eve Sill observe the whole surface OF
the sunand in this respect differing from the spots
which are wholly confined TO the sun's. equatorial
regon~a nothing. or roughness OF THO sur ,lj
face 1t is supposed by some mat tls mo td,t
~Ri1c.liGs or wiiiow-leaye particles, irregulMly
scattered over tho surface Of tho sun, these patches
being the most numerous III those parts oil me ai5f