ASTRONOMY OF THE HEAVENS FOR JUNE.

By Prof. M. B. GOFF.

THE SUN

In the northern hemisphere the longest day of this year is the 20th of this month; though in many places it would be difficult to notice that there was really any difference between the length of this day and that of a few of those preceding and succeeding. The sun has reached his farthest point northward, and, although he travels about his usual distance each day, he moves in a part of his orbit which is, for all practical purposes, parallel to the equator, and hence must rise about the same place and hour each morning, and set at the same place and hour every evening. About the 21st of December of each year we have the shortest day, with several of the neighboring days but very little longer; for the reason that at that date the sun reaches its southern limit and moves almost parallel to the equator.

It may be interesting to see how our neighbors fare in regard to longest days. By the working of a few problems in spherical trigonometry we find that our friends living on the equator have all their days the same length, namely, twelve hours. So that there is in that region no looking forward to the long winter evenings, nor any hoping for the shortening of summer’s sultry days. They have, however, this advantage: If the sun’s rays do sometimes “come down by a straight road,” they do not continue so long at a time as with us. As we proceed north, we find in latitude 30° 48′ that the longest day is fourteen hours, in latitude 49° 2′, sixteen hours; in 58° 27′, eighteen hours; in 63° 23′, twenty hours; in 65° 48′, twenty-two hours; in 66° 32′, twenty-four hours, no night at all; and 51′ further north, that is, in latitude 67° 23′, the longest day begins about the fifth of June, and lasts till about the fourth of July, and is about thirty days long; in 73° 40′, it is three months long; in 84° 5′, it is five months; and at the north pole six months. Practically the days are longer than here represented; for we have natural light enough to pursue most vocations both before sunrise and after sunset. In latitude 63° 23′, for example, where the day’s extreme length is twenty hours, on account of the twilight the remaining four hours might as well be called daylight, for the sun descends only a few degrees below the horizon, and though hidden from sight, still through the medium of the atmosphere affords almost the usual light of day.

Of course our friends in the corresponding latitudes of the southern hemisphere are enjoying correspondingly short days and long nights. In 63° 23′ south latitude the day is only four hours long, and the night twenty hours. No wonder people sometimes say, “This is a queer world.” Its mechanism is certainly very wonderful. If we wished to be somewhat exact, we would say that the sun enters Cancer and summer begins on June 20th, at 7:51 p. m., Washington mean time, and continues ninety-three days, fourteen hours twenty-two minutes. Other items are as follows: On the 1st, 15th, and 30th, the sun rises at 4:31, 4:28, and 4:29 a. m.; and on the same dates sets at 7:24, 7:32, and 7:34 p. m. During the month our days vary in length from fourteen hours fifty-three minutes to fifteen hours five minutes; and on the 20th, the time from early dawn till the end of twilight is nineteen hours thirty minutes. On the 3rd, at 4:00 p. m., the sun is in conjunction with Saturn; on the 14th, at 3:00 p. m., 90° west of Uranus; on the 30th, at midnight, farthest from the earth; greatest elevation, in latitude 41° 30′ north, 71° 57′. Diameter decreases from 31′ 36″ on the 1st, to 31′ 32″ on the 30th.

THE MOON’S

Phases occur in the following order: Full moon on the 8th, at 2:41 p. m.; last quarter, on 16th, at 9:26 a. m.; new moon, on 23rd, at 12:25 a. m.; first quarter, on 30th, at 1:06 a. m. On the 1st, the moon sets at 12:38 a. m.; on the 15th, rises at 11:45 p. m.; and on the 29th, sets at 11:42 p. m. Is farthest from the earth on the 16th, at 10:18 p. m.; nearest to earth on 21st, at 10:30 p. m. Least meridian altitude on 9th, 29° 41′; greatest altitude on the 22nd, amounting to 67° 18⅓′.

MERCURY.

A pair of good sharp eyes looking out sufficiently early in the morning, can almost any day during the month get a view of this planet; especially will this be the case near the 12th, the day on which it reaches its greatest western elongation, amounting to 23° 19′. On the 1st, 15th, and 30th, the time of rising is 3:51, 3:23, and 3:37 a. m. On the 21st, at 12:41 p. m., it will be 1° 39′ north of the moon, and on the 26th, at 6:00 p. m., one minute of arc north of Saturn.

VENUS.

This planet which has for several months been so conspicuous in the western sky, reaches its greatest brilliancy on the 3rd, after which it will decrease in interest, and continue to appear each day smaller, until its light is again obscured by the sun, and after remaining for a short time hidden from view, again appears in the eastern horizon as the Lucifer (light-bearer) of the ancients. It will set at 10:24, 9:40, and 8:21 p. m., respectively, on the evenings of the 1st, 15th, and 30th. Its diameter will increase from 35.8″ to 55.2″; but as it “turns its back upon us,” its increasing diameter will not add to the amount of light furnished the earth.

MARS.

On the 1st Mars will be found quite close to, and a little to the east of the star Regulus, in the constellation Leo, and will move east somewhat rapidly, making a direct movement of 14° 31′ 55.5″ from the 1st to the 30th. His diameter decreases from 6.6″ to 5.8″, indicating his continually increasing distance from the earth. He rises during the day and sets at the following hours: On the 2nd at 12:07 a. m.; on the 15th at 11:30 p. m.; and on the 30th at 10:49 p. m.

JUPITER

During the month moves about six degrees eastwardly from a point a little west of Præsepe, in Cancer, leaving the Nebula a little to the north, and reaching, on the 30th, a point a little northeast of Delta Cancri. He comes to the meridian on the 1st, 15th, and 30th, at 3:34.6, 2:50.2, and 2:03.5, p. m., and sets on the same days at 10:49, 10:01, and 9:12 p. m., respectively.

SATURN,

Who has for several months been making of himself such a fine display, exhibiting to those who were fortunate enough to possess a moderately good telescope, a splendid view of his rings, now retires abashed before the “King of Day;” during the first of the month, not even deigning “to put in an appearance.” But he only “bides his time.” For during the succeeding months he will be cheerfully “at home” to early risers. It will be observed that on the 1st he rises after and sets before the sun, namely, at 4:51 a. m. and 7:23 p. m.; on the 15th, rises at 4:02, twenty-six minutes before the sun, and sets at 6:36 p. m., some fifty-six minutes earlier than the sun; and on the 30th rises at 3:11 a. m., and sets 5:47 p. m. On the 3rd, at 4:00 p. m. he is in conjunction with and about 1° 23′ south of the sun; and on the 21st, at 10:30 p. m., 2° 46′ north of the moon. Diameter, 15.6″.

URANUS

Makes an advance movement of 22′ 30″, presenting a diameter of 3.7″. Is evening star during the month, setting at the following times: On the 2nd at 1:07 a. m.; on the 16th at 12:12 a. m.; and on the 30th at 11:14 p. m. On the 14th at 3:00 p. m., is 90° east of the sun; on the 1st at 3:54 p. m., is 3° 21′ north of the moon, and again on the 28th at 11:42 p. m., 3° 21′ north of the moon.

One of the odd things in astronomy is the story of the satellites of Uranus. In a work published as recently as 1852, we are gravely told that Uranus “is attended by six moons or satellites, which revolve about him in different periods, and at various distances. Four of them were discovered by Dr. Herschel and two by his sister, Caroline Herschel, with the promise of more to be discovered;” and then we are given their distances from the planet, and also their times of revolution, which vary from 224,000 to 1,556,000 miles as to distance, and from five days, twenty-one hours, twenty-five minutes, twenty seconds to one hundred and seven days, sixteen hours, thirty-nine minutes, fifty-six seconds, as to times of revolution. But now we are told Herschel’s “satellites have been sought for in vain, both with Mr. Lassell’s great reflectors and with the Washington twenty-six inch refractor, all of which are optically more powerful than the telescopes of Herschel. There may be additional satellites which have not yet been discovered; but if so, they must have been too faint to have been recognized by Herschel.” Our latest information on this subject gives four satellites named Ariel, Umbriel, Titania, Oberon, in order outwardly from the planet, and their periodic times, respectively, 2.52, 4.14, 8.7, and 13.46 days; the credit of discovering the two outer ones being given to Herschel and that of the two inner being divided between Mr. Lassell and Mr. Struve.

NEPTUNE

Will be one of our morning stars, rising at 3:35, 2:45, and 1:48 a. m., on the 1st, 15th, and 30th, respectively. His motion, 58′ 39″ direct; diameter, 2.5″.