Western Sky Research Articles

On the diurnal variation of [OI] 5577 in the nightglow

Observations in the Mojave Desert of the diurnal variations of the zenith intensity of the forbidden oxygen line at 5577 A for ten nights over a two-year interval are recorded. In general, a maximum of intensity occurs at local midnight, ±2.5 hours. A detailed study of one night is reported wherein the diurnal variation of regions of the sky other than the zenith are shown to follow time patterns similar in general but with significant variations in detail. The intensity changes of various parts of the sky are interpreted as geographical variations of local zenith intensity. Isophotal plots of these geographical variations throughout the night indicate the presence of definite patterns in the upper atmosphere. During the post-twilight period, an enhancement of intensity is observed in the western sky. In the predawn observations, no enhancement is noted in the eastern sky. Between the post-twilight and predawn, the intensity goes through a maximum which is partially localized to the north of our station. Evidence is presented which indicates that the over-all intensity change can be described as a fixed excitation pattern on the dark side of the earth through which a given observer seems to move with the rotation of the earth. The character of the pattern seems to change with the season. The variation of intensity with zenith distance for the whole night indicates an effective height of emission of 250 km.

The Night Sky in December

FULL moon occurs on Dec. 5d. 15h. 13m., U.T., and new moon on Dec.19d. 18h. 55m. The following conjunctions with the moon take place : Dec. 12d. 23h Satutn 0·3° S.; Dec. 13d. 09h., Mars 0·6° N. Dec 20d. 23h., Mercury 3° N.; Dec. 22d. O8h, Jupiter 4° N. ; Dec. 22d. 23h., Venus 4° N. In audition to these conjunctions with the moon, Venus is in conjunction with Jupiter on Dec. 7d. 03h., Venus being 2° S. Mercury is unfavourably placed for observation during the first part of the month, but at the end of the month the planet sets 1h. 20m. after sunset and can be seen in the western sky for a short time. Venus sets more than three hours after the sun during December and is conspicuous in the western sky, attaining its greatest brilliancy (stellar magnitude –4·4) on Dec. 26. On this date the visible portion of the illuminated disk is only 0·26, but the planet is then only 38 million miles from the earth. Mars rises abou hours int midnight up to the middle of the month and at 23h. 27m. at the end of the month and can be seen in the morning the constellation of Virgo fairly close to β Virginis about the middle of the month. Jupiter sets at 19h. 35m., 18h. 55m. and 18h. 13m. at the beginning, middle and end of the month, respectively, and is easily seen, lying low in the constellation of Capricornus. Saturn rises soon after midnight on Dec. 1 and at 22h. 17m. on Dec. 31, on which date it is stationary, and can be seen a little east of σ Leonis. Occultations of stars brighter than magnitude 6 are as follows : Dec. 3d. 22h. 53·6m., τ Arie. (D); Dec. 6d. 17h. 52·lm., 136 Taur. (D); Dec. 6d. 18h. 46·7m., 136 Taur. (R); Dec. 8d. 5h. 14·9m., 47 Gemi. (R); Dec. 9d. Oh. 32·4m., ω Canc. (R); Dec. 23d. 16h. 43·9m., XCapr. (D); Dec. 25d. 17h. 10·6m., XAquar. (D); Dec. 31d. 19h. 18·Om., 104 B. Taur. (D). D and R refer to disappearance and reappearance, respectively, and the latitude of Greenwich is assumed. Winter solstice occurs on Dec. 22d. 04h.

The Night Sky in November

FULL moon occurs on Nov. 5d. 21h. 09m., U.T., and new moon on Nov. 20d. 07h. 29m. The following conjunctions with the moon take place: Nov. 15d. O1h., Mars 1° S. ; Nov. 15d. 14h., Saturn 0·8° S. ; Nov. 23d. 19h., Venus 2° N. ; Nov. 24d. 13h., Jupiter 5° N. In addition to these conjunctions with the moon, Mars is in conjunction with Saturn on Nov. 3Od. 21h., Mars being 0·2° N. Mercury rises about 1¼ hr. before the sun on Nov. 1 and is visible in the eastern sky, but draws closer to the sun and is in superior conjunction on Nov. 21. Venus sets about two hours after the sun and is conspicuous in the western sky, stellar magnitude -4, the visible portion of the illuminated disk varying between 0·6 and 0·44. Mars rises soon after midnight throughout the month. Jupiter sets at 21h. 10m., 20h. 25m. and 19h. 40m. on Nov. 1, 15 and 30 respectively, but in the latitude of Greenwich does not rise more than 18° above the horizon. Saturn, in the constellation of Leo, rises at 2h., Ih. 10m. and Oh. 15m. at the beginning, middle and end of the month respectively. Occultations of stars brighter than magnitude 6 are as follows: Nov. 3d. 20h. 30·4 m., ζ Pise. (D) ; Nov. lOd. 21h. 32·1m., 47 Gemi. (R). D and R refer to disappearance and reappearance respectively, and the latitude of Greenwich is assumed. The Leonid meteors are due during Nov. 14–19 and the Andromedids during Nov. 18–23, but these showers are now feeble and supply comparatively few meteors.

The Night Sky in June

FULL moon occurs on June l0d. 21h. 45m., U.T., and new moon on June 260.10h.02m. The following conjunctions with the moon take place : June 3d. 04h., Saturn 3°S. ; June 13d. 22h., Jupiter 5° N.; June 24d l5h., Mars 4° S.; June 24d. 18h., Mercury 8°S June 27d. 21h., Venus 4° S.; June 30d. 13h., Saturn2° S. Mercury is in inferior conjunction on .June 3 and is, stationary on June 15. The planet reaches greatest western elongation on June 28, and at the end of the month rises an hour before the sun. Venus is an evening star, setting about an hour after the sun during June, and can be seen for a short time in the western sky. Mars is a morning star, rising at 3h. 10m., 2h. 40m., arid 2h. 12m., at the beginning, middle and end of the month, respectively, and is visible for a short time in the eastern sky. Jupiter is visible in the early morning hours, Arising at 23h. 30m., 22h. 33m., and 21h. 30m. on June 1, 15 and 30, respectively. Saturn is visible during the earlier portion of the night, setting at Oh. 40m., 23h. 45m. and 22h. 50m. at the beginning, middle and end of the month, respectively. No occultations of stars occur during June. Summer solstice commences on June 21d. 18h.

The Night Sky in May

FULL moon occurs May 12d. 12h. 51m., U.T., and new moon or May 27d. 22h. 24m. The following conjunctions with the moon take place : May 6d. 20h., Samuni 3° S. ; May 17d. 14h., Jupiter 5° N. ; May 26d 16h., Mars 2° S. ; May 27d. 12h., Mercury 0 8° S. Mercury is an evening star, setting at 21h. 21h. 43m. and 20h. 16m., at the beginning, Middle and end of the month, respectively ; but in the latter case it is too close to the sun to be observed. The planet attains its greatest eastern elongation on May 10. Venus is an evening star and can be seen for a short time in the western sky after the middle of the month, setting 35 min. and nearly an hour after the sun on May 15 and 31, respectively. Mars is a morning star but rises too soon before the sun for favourable observation. Jupiter rises at Ih. 30m., Oh. 35m. and 23h. 33m., on May 1, 15 and 31, respectively, and is visible for a few hours before sunrise. The planet is stationary on May 20. Saturn is visible until after midnight, setting at 2h. 40m., Ih. 45m. and Oh. 45m., at the beginning, middle and end of the month, respectively, and is stationary on May 1. Only one occultation of stars brighter than magnitude 6 occurs, λ Cane, disappearing at 21h. 30·6m. on May 4.

The Night Sky in April

FULL moon occurs on April 13d. 04h. 08m., U.T., and new moon on April 28d. 08h. 02m. The following conjunctions with the moon take place : April 9d 13h., Saturn 3°S.; April 20d. 03h., Jupiter 5° N.; April ji9a. 21h Mercury 0·7° S. Mercury is in superior conjuction on April 13 and is not favour-ably placed for observation until later in the month ; the planet sets Ih. 45m. after the sun on April 30, and can be seen in the western sky. Venus, in superior conjunction on April 16, is too close to the sun for favourable observation throughout the month. Mars rises about the same time as the sun during April, and cannot be observed. Jupiter is a morning star, rising at 3h. 20m., 2h. 30m. and Ih. 35m., at the beginning, middle and end of the month, respectively, and can be seen low down for a few hours before sunrise. Saturn sets in the early morning hours and is visible throughout the greater part of the night. Occultations of stars brighter than magnitude 6 are as follows : April Id. 19h. 46 3m., 45 Arie. (D); April 7d. OOh. 31·4m., c Gemi. (D) ; April lid. 20h. 56·3m., η Virg. (D). D refers to disappearance, and the latitude of Greenwich is assumed. The Lyrid meteor shower is active about April 18-24. A total eclipse of the moon, visible at Greenwich, takes place on April 13, the circumstances of which are given as follows: moon enters penumbra, Olh. 31·6m. ; enters umbra, 02h. 27·7m. ; total eclipse begins, 03h. 28·Om. ; middle of eclipse, 04h. 10·9m. ; total eclipse ends, 04h. 53·8m. ; moon leaves umbra, 05h. 54·3m. ; leaves penumbra, O6h. 50·3m. A partial eclipse of the sun, visible at Greenwich, occurs on April 28, its magnitude being 0·41 at Greenwich, where it begins at 6h. 21m., reaches its greatest phase at 7h. 15m., and ends at 8h. 14m.

The Night Sky in October

NEW moon occurs on Oct. 2d. 19h. 42m., U.T., and full moon on Oct. 18d. 02h. 23m. The following conjunctions with the moon take place : Oct. 4d. llh., Mercury 4° S.; Oct. 5d. 18h., Mars 1° N. ; Oct. 8d. 02h., Jupiter 4° N. ; Oct. 27d. 17h., Saturn 4° S. ; Oct. 29d. 07h., Venus 2° S. ; Oct. 31d. 00h., Mercury 0·5°N. In addition to these conjunctions with the moon, Venus is in conjunction with Regulus on Oct. 5d. 21h., Venus 0·4° S., and on Oct. 8d. 20h. Venus is in conjunction with Saturn, Venus 1·1° S. Mercury, in inferior conjunction on Oct. 20 and stationary on Oct. 28, is unfavourably placed for observation during the greater portion of the month. On Oct. 31 the planet rises 1h. 40m. before the sun and can be seen in tlie eastern sky. Venus rises at 2h., 2h. 40m. and 3h. 15m. at the beginning, middle and end of the month, respectively, and can be seen in the morning hours, stellar magnitude —3·6, the visible illuminated portion of disk varying between 0·64 and 0·74. Mars sets a little more than an hour after the sun during October and is not well placed for observation. Jupiter sets at 20h. 36m., 19h. 50m. and 18h. 57m. on Oct. 1, 15 and 31, respectively, and is visible in the western sky (stellar magnitude —1·6) for some time after sunset. Saturn rises at 2h. 30m. and 0h. 50m. at the beginning and end of the month, and can be seen in the morning hours, stellar magnitude 0·9. Occultations of stars brighter than magnitude 6 are as follow : Oct. 14d. 21h. 47·8m., Ψ3 Aquar. (D) ; Oct. 21d. 00h. 16·Om., 32 Taur. (R); Oct. 25d. 03h. 47·2m., ω Cane. (R) ; D and R refer to disappearance and reappearance, respectively, and the latitude of Greenwich is assumed. The Orionid meteors are due about October 16-24, but moonlight will partly interfere with observation of this shower.

The Night Sky in July

NEW moon occurs on July 6d. 21h. 09m., U.T., and full moon on July 21d. 02h. 31m. The following conjunctions with the moon take piace: July 5d. 16h., Venus 8° S. ; July 5d. 18h., Mercury 8° S. ; July 9d. 06h., Saturn 4° S. ; July ud. 16h., Mars 3° S. ; July 18d. Olh., Jupiter 4° N. Mercury is too dose to the sun in the early part of the month to be observed, but in the middie of the month the planet rises an hour before sunrise and attains its greatest westerly elongation on July 16. At the end of the month Mercury rises at 3h. 16m., about an hour before sunrise. Venus rises about a quarter of an hour before the sun on July 1 but can be observed later in the month, rising at 2h. 28m. and lh. 41m. on July 15 and 31, respectively. The planet attains its greatest easterly elongation on July 16 and its greatest brilliancy on July 31, when its stellar magnitude is -4·2. Mars sets at 23h. 10m., 22h. 30m. and 21h. 45m. at the beginning, middie and end of the month, respectively, and can be seen for a short time in the western sky after sunset. Jupiter, in the constellation of Ophiuchus, is visible during the early part of the night, setting at 2h. 40m., lh. 36m. and Oh. 33m. at the beginning, middie and end of the month, respectively. Owing to its large declination south, nearly 23°, the planet is not very well placed for observation in high northern latitudes. Saturn sets about an hour before Mars and cannot be observed very long after sunset ; at the end of the month it sets a littie mdre than half an hour after the sun. No occultations of stars brighter than magnitude 6 take placa in July. The earth reaches aphelion on July 4, when its distance from the sun is 94,561,000 miles.

The Night Sky in June

NEW moon occurs on June 7d. 12h. 55m., U.T., and full moon on June 21d. 12h. 54m. The following conjunctions with the moon take place : June 8d. 23h., Mercury 4° S. ; June 9d. 04h., Venus 3° S. ; June 11d. 17h., Saturn 4° S. ; June 13d. 08h., Mars 4° S. ; June 21d. Olh., Jupiter 4° N. In addition to these conjunctions with the moon, Mercury is in conjunction with Venus on June 30d. 19h., Mercury being 1·0° S. Mercury is an evening star at the beginning of the month, but towards the middle of the month is too close to the sun for favourable observation, and is in inferior conjunction on June 24. Venus is conspicuous in the western sky, setting at 22h. 35m. and 21h. 10m. on June 1 and 15 respectively, and is in inferior conjunction on June 24. Mars is still visible as an evening star, setting at Oh. 48m. and 23h. 15m. at the beginning and end of the month respectively, and Saturn, which is fairly close to Mars, sets on the corresponding dates shortly after midnight and 22h. 22m. respectively. Jupiter, in opposition on June 15, is visible throughout the night, but is rather low for good observation in northern latitudes. No occultations of stars brighter than magnitude 6 occur in June. Summer solstice occurs on June 21d. 12h.

Bret Harte Goes East: Some Unpublished Letters

l ITERARY CRITICISM in our time has not dealt kindly with Bret EJHarte. But those who live in the West still have an interest in him apart from his intrinsic merit as a man of letters, for he was the first to memorialize (and, incidentally, to romanticize) the California mining country and the ragtag of rough-hewn characters who gave it color. In San Francisco, in Los Angeles, and in virtually every other California community, Bret Harte schools, libraries, parks, and streets bear witness to the fame of the brilliant comet that once streaked out of the Western sky across an awed continent, glowed incandescently in Boston for a while, and suddenly burned out. Like everybody else in California, Bret Harte was born in the East. He was strictly a dude rancher in the West and actually had very little sympathy with the forty-niners and their way of life. But he did have a remarkably discerning journalistic eye for mannerisms and habits of speech, and he was clever enough to pour old wine into new bottles, to take conventional story formulas and give them the aura of novelty that goes with an unusual setting. originality of Bret Harte, whiclh Eastern critics considered his chief virtue, was more seeming than real. It is now well known that he had to be pushed into his rightful field. Anton Roman, who founded the Overland Monthly, laid the talents of young Bret Harte (he was only thirty-two) under contribution with the specific proviso that he give over his highly sentimentalized, Irvingesque Spanish California legends in favor of local and contemporary material. result is common knowledge. The Luck of Roaring Camp vas followed by The Outcasts of Poker Flat, and, like Byron, Bret Harte awoke one morning to find himself famous. His brisk reportorial style, his mastery of picturesque narrative, and his shrewd understanding of the universal appeal of an artful blending of sentiment and wvit proved to be a combination of literary virtues that won immediate praise. Harte's social inclinations, as well as his literary aspirations, drew him inevitably toward Boston. Here, it seemed, were the charm and grace and ease of the cultured, intellectual life. Here was the hub of the world of American letters. Why, he was to say, you couldn't fire a revolver from your front porch anywhere wvithout bringing down a two-

The Night Sky in December

New moon occurs on Dec. 12d. 12h. 53m., u.t., and full moon on Dec. 27d. 20h. 27m. The following conjunctions with the moon take place: Dec. 3d. 14h., Saturn 4° S.; Dec. 4d. 04h., Mars 3° S.; Dec. lid. llh., Mercury 2° N.; Dec. 14d. 20h., Venus 3° N.; Dec. 30d. 21h., Saturn 4° S.; Dec. 31d. 23h., Mars 2° S. In addition to these conjunctions with the moon, Mercury is in conjunction with Jupiter on Dec. 15d. 02h., Mercury being 0·6° S. Mercury is a morning star throughout most of the month, rising at 6h. 04m., and 7h. 12m. at the beginning and middle of the month respectively; on Dec. 31 the planet rises 12m. after the sun. Venus, an evening star, is conspicuous in the western sky for some time after sunset as an object of stellar magnitude – 3·4; about 0·9 of the illuminated1 portion of the apparent disk is visible during the month. Mars, in the constellation of Leo, can be seen throughout the greater portion of the night, rising at 22h. 23m., 21h. 52m., and 21h. 04m., at the beginning, middle and end of the month, respectively, and is easily recognized from its proximity to Regulus, from which it moves eastward during the month. Jupiter, in conjunction with the sun on Dec. 1, is unfavourably placed for observation until the end of the month, when it is a morning star rising about 1¾ hours before the sun. Saturn, in the constellation of Leo, is well placed for observation, rising at 21h. 46m., 20h. 50m., and 19h. 44m., at the beginning, middle and end of the month, respectively. Occultations of stars brighter than magnitude 6 are as follows: Dec. 2d. 04h. 53·2m., λ Cane. (R); Dec. 8d. 06h. 20·5m., m. Virg. (R); Dec. 25d. 23h. 40·2m., x Taur. (D); Dec. 26d. 00h. 09·7m., u Taur. (D). The times are given for Greenwich, and D and R refer to disappearance and reappearance, respectively. The Geminid meteors are active in the early part of the month; they have usually short paths and are not very bright. Winter solstice takes place on Dec. 22d. 17h.

The Night Sky in July

FULL moon occurs on July 14d. 09h. 22m. U.T. and new moon on July 28d. 11h. 53m. The following conjunctions with the moon take place: July 1d. 19h., Venus 3° S. ; July 3d. 07h., Mars 4° S. ; July 6d. 11h., Jupiter 4° S. ; July 31d. 15h., Venus 5° S. ; July 31d. 23h., Mars 5° S. Occultations of stars brighter than magnitude 6 are as follows, in the latitude of Greenwich: July 7d. 20h. 37.3s., x Virg. (D); July l1d. 21h. 19.5m., b Ophi. (D); July 18d. 0lh. 17.lm., 69 Aquar. (R). Mercury can be seen in the western sky in the early portion of the month, but later on it is too close to the sun for favourable observation. The planet attains its greatest western elongation on July 5 and is stationary on July 19. Venus sets at 22h. 16m. and 21h. 15m. at the beginning and end of the month respectively, and is conspicuous in the western sky. The stellar magnitude of the planet is -3.5 in the earlier portion, and -3.6 in the later portion, of the month. Mars sets 2½ hours after the sun on July 1, but at the end of the month only 1½ hours after the sun and is not well placed for observation in the latter case. Jupiter, near 0 Virgin is, sets at midnight on July 1 and about 1½ hours after the sun on July 31. The stellar magnitude of the planet varies from - 1.7 to - 1.5 during this period. Saturn is drawing in too close to the sun for favourable observation. The earth reaches aphelion on July 3d.

The Night Sky in June

FULL moon occurs on June 14d. 18h. 42m., U.T., and new moon on June 29d. 04h. 06m. The following conjunctions with the moon take place: June 2d. 00h., Venus 0-2° S. ; June 2d. 18h., Saturn 3° S. ; June 4d. 19h., Mars 3° S. ; June 9d. 03h., Jupiter 4° S. ; June 30d. 10h., Saturn 3° S. ; June 30d. 23h., Mercury 3° S. In addition to these conjunctions with the moon, the following conjunctions occur: June 12d. 13h., Venus in conjunction with Saturn, Venus 1.7° N.; June 18d. 05h., Mars in conjunction with Regulus, Mars 0.8° N. ; June 24d. 01h., Mercury in conjunction with Saturn, Mercury 1.5° N. Occultations of stars brighter than magnitude 6 are as follows, the latitude of Greenwich being assumed: June 13d. OOh. 48.5m., p Scor. (D) ; June 13d. OOh. 49.6m., 56B. Scor. (D) ; June 13d. Olh. 24.9m., (3 Scor. (R). Mercury sets about 11/2 hours after the sun from the middle to the end of June and can be seen in the western sky after sunset. Venus is conspicuous in the western sky, setting at 22h. 28m. and 22h. 17m., at the beginning and end of the month respectively. The portion of the illuminated disk visible on the earth varies between 0.85 and 0-77 during June 1-30. Mars can be seen before midnight, setting at Oh. 19m., and 22h. 54m. at the beginning and end of the month respectively. The stellar magnitude of the planet varies from 1.5 and 1.7 between the above dates. Jupiter sets at 2h., and Oh. 06m. at the beginning and end of the month respectively and is stationary on June 15. The stellar magnitude of Jupiter is -1.8 throughout the month. Saturn sets nearly 3 hours after the sun on June 1, but after the middle of the month is too close to the sun for good observation. The fact that all five planets are visible at the same time towards the end of the month is worth noticing. An eclipse of the sun, invisible at Greenwich, occurs on June 29, and on June 14 a total eclipse of the moon, partly visible at Greenwich, takes place. The moon leaves the umbra at 20h. 33.6m. and the penumbra at 21h. 45.lm., and as moonrise at Greenwich occurs at 20h. 17m., very little of the eclipse is visible. Summer solstice is on June 2Id. Olh.

The Night Sky in May

NEW moon occurs on May Id. 13h. 16m., U.T., and full moon on May 16d. 02h. 52m. The following conjunctions with the moon take place: May 3d. 02h., Venus 2° N.; May 6d. 05h., Saturn 2° S. ; May 7d. 10h., Mars 2° S. ; May 13d. 01h., Jupiter 3° S. No occupations of stars brighter than mag. 6 take place during the month. Mercury is in superior conjunction with the sun on May 31 and is not well placed for observation throughout the month. Venus is a conspicuous object in the western sky and sets about two hours after the sun during the month. The portion of the illuminated disk visible from the earth varies from 0-93 to 0-86 during May. Mars and Saturn are still visible in the earlier portion of the night, the former setting at midnight on May 31 and the latter about an hour earlier. Jupiter is still favourably placed for observation and does not set until 4h. 07m. and 2h. 10m. at the beginning and end of the month respectively. There is a partial eclipse of the sun on May 30, invisible at Greenwich.

The Night Sky in March

NEW moon occurs on March 3d. 18h. 01m. U. T. and full moon on March 17d. 19h. llm. The following conjunctions with the moon take place: March 4d. 20h., Mercury 6° N. ; March 12d. llh., Mars 1° N. ; March 12d. 14h., Saturn 2° S. ; March 20d. 01h., Jupiter 3° S. In addition to these conjunctions with the moon, the following conjunctions occur: March 18d. 08h., Mercury in conjunction with Venus, Mercury 5° N. ; March 19d. 01h., Mars in conjunction with Saturn, Mars 3° N. No occultations of stars brighter than mag. 6 occur during the month. Mercury is visible in the western sky in the first portion of the month, setting nearly 1½ hours after the sun. Venus is conspicuous in the western sky, setting at 18h. 04m., 18h. 49m., and 19h. 41m. at the beginning, middle and end of the month respectively. Mars, in the constellation of Gemini, can be seen during the greater part of the night and does not set at the end of the month before 3h. 19m. Jupiter is well placed for observation, rising at 21h., 54m., 20h. 54m., and 19h. 40m. on March 1, 15 and 31 respectively. Saturn is easily recognized close to Mars, a conjunction of the planets taking place on March 19. The planet is stationary on March 20. Spring equinox occurs on March 2Id. 06h.

The Night Sky in March

NEW moon occurs on March 14d. 03h. 51m., U.T., and full moon on March 28d. 17h. 44m. The following conjunctions with the moon take place: March 11d. 21h., Mars 2° N.; March 16d. 10h., Venus 12° N.; March 21d. 03h., Saturn 0·4° N.; March 27d. 05h., Jupiter 3° S. During March no occultations of stars brighter than magnitude 6 take place. Mercury is close to the sun at the beginning of the month, rising about 20 minutes after, and setting 10 minutes before, the sun then. At the end of March the times of rising and setting are 5h. 47m. and 20h. 09m., respectively. The planet attains its greatest easterly elongation on March 26. Venus is a very conspicuous object in the western sky and is well placed for observation, setting at 21h. 54m. and 21h. 04m. at the beginning and the end of the month, respectively. Venus attains its greatest brilliancy on March 10. Mars, a morning star, is too close to the sun for favourable observation. Jupiter moves from the constellation of Virgo into the constellation of Leo during March, and can be seen throughout the night, setting at 7h. 26m. and 5h. 17m. on March 1 and March 31. The planet is in opposition to the sun on March 13. Saturn, in the constellation of Gemini, sets at 3h. 47m. and lh. 53m. on March 1 and March 31, and is stationary on March 5. Vernal equinox is on March 21d. 00h.

The Night Sky in May

THE duration of night (sunset to sunrise) decreases from 9-3 hours on May 1 to 7-7 hours on June 1 in the latitude of London. Full moon is on May 11 and new moon on May 26. ]STo bright star is occulted by the moon during the month. There is a general absence of bright planets in the night sky of this month. Jupiter and Saturn are now too near the sun for observation. Towards the end of May, however, conditions are favourable for seeing Mercury in the low western sky after sunset. In mid-May, Mars is nearly 5° above the eastern horizon soon after 3h. 30m. U.T., but sunrise is shortly after 4h. (add 2 hours to convert to new Summer Time). About this date the following constellations are near the southern meridian at dusk: Ursa Major, Canes Venatici, Coma Berenices, Bootes, Leo, Virgo, Crater, Corvus and Hydra. Pleasing in its symmetry is the formation of seven stars of medium brightness in Corona Borealis. A nova appearing near e Coronae Borealis in 1866 added to the lustre of this ‘crown’.

The Night Sky in March

THE time of the spring equinox is March 20 18h. when the sun enters the sign Aries. The moon is new on March 9 and full on March 23. Lunar conjunctions with the planets occur as follows: March lid. 8h., Jupiter: 12d. 14h., Saturn: 12d. 23h., Venus: 14d. 0h., Mars. It will be seen from these times that the grouping of the bright planets is still a conspicuous feature of the western sky after sunset, although Jupiter is being lost to view as the month proceeds. On March 8d. 14h., Venus is in conjunction with Saturn, and on March 26d. 14h. with Uranus. Mars is in conjunction with Uranus on March 16. Neptune is in opposition on March 14, the distance from the earth being 2,716 million miles. The constellations of bright stars associated with winter evenings are now well westwards when the sky darkens after sunset. The regions of the sky which follows—Leo, Virgo, Ursa Major and Bootes—though less spectacular to the unaided eye, are of great interest on account of the rich fields of extra -galactic nebulae. With small or moderate optical aid, there is also a number of interesting double stars well worth examining, including Castor (separation of components 3·6″), γ Leonis (4·0″), ζ Ursse Majoris (1·7″), γ Virginis (5·7″), ζ Ursse Majoris (14″) and ζ Herculis (1·1″). The last binary has a period of about 35 years and was discovered in 1782 by Sir William Herschel; the greatest separation of its components is ½″. Under favourable conditions the Zodiacal Light may be seen after sunset during this month. On fine evenings when the moon is absent, it is also worth while looking for auroras, for in March occurs one of the semi-yearly peaks in aurorse frequency. [All times are given in Universal Time; subtract 1 hour from Summer Time.]

The Night Sky in June

THE summer solstice on June 22 brings the shortest night lasting, inthe northern latitude of Greenwich, less than 7½ hours, according to the sun's setting and rising, and a little more than 3 hours if twilight (nautical) be taken into account. The moon is full on June 12d 23·8h and new on June 27d 21·2h U.T. A lunar conjunction takes place with Jupiter on June 19d 3h: with Saturn on June 22d 15h and with Venus on June 30d 14h. Venus, a bright star in the evening western sky, sets at about 22½h, preceded by Mars. Jupiter rises before Oh after June 10 ; its present stellar magnitude is about –2·1, as compared with –3·4 for Venus. Saturn is reappearing in the skies as a morning star, and in the middle of the month rises after lh. About 21h in mid-June, Arcturus stands out conspicuously on the southern meridian. Lower in the south at this time will be found Spica just west of the meridian and Antares on the east. Antares, with a radius 450 times that of the sun's, has an averagemean density of only 1/3,000 that of air at N.T.P. From a radiant not far from Antares come the slow-moving fireballs known as Scorpiids. Two interesting double stars in Bootes may be noted—ɛ Bootis, having the euphonious name of Pulcherrima, is a beautiful double the components of which, separated by 2½", are a 3rd magnitude yellow star and a blue star of magnitude 6½ξ Bootis, with a period of about 160 years and an orbit of great eccentricity, comprises a yellow star (mag. 4·7) and a purple star (mag. 6·6) separated by about 4½". α Herculis provides another finely coloured pair-a mag. 3-0 orange star and a blue green mag. 6·1also separated by 4½". Between η and ζ Herculis may be seen a nebulousspot of light which is the well-known globular cluster in Hercules. Thestellar population of this spherical system is not less than 50,000 stars ; these occupy a volume of space (500 light years across) which would be able to contain the greater number of our naked-eye stars.

The Night Sky in April

Full moon occurs on April 14 at 18·3h and new moon on April 30 at 5·5h U.T. No stars brighter than mag. 6 o 1 are occulted during the month ; for particulars of the seven occupations visible from Greenwich, see page 526 of the “Nautical Almanac”. Lunar conjunctions with the planets occur as follows: on April 2d 23h with Venus: April 2d 6h with Mercury: April 3d 8h with Mars: April 25d 2h with Jupiter and April 28d llh with Saturn. On April 8d 16h, Mercury and Venus are in conjunction, and on April 15d 20h Venus and Uranus, Venus being only 0·1° north of Uranus (geocentric positions). Venus and Mars are both evening stars ; Mercury is an evening star until April 21, and at greatest eastern elongation on April 2. On April 1 at about 19h, the moon's slender crescent and the planet Venus will be nearly at the same altitude low in the western sky. In mid-April at 22h, Orion will have nearly set in the west, but Procyon, Castor and Pollux still remain. Capella in the north-west balances Vega in the north-east. The bright star Arcturus, the spectrum of which closely resembles that of sunspots, is conspicuous east of the meridian. Arcturus has the notable proper motion of 2·3"per annum. In its train, there is the small, beautiful constellation of Corona Borealis. On or about April 21, the Lyrid meteors may be looked for, their radiant point being at R.A. 18h 4m and Dec. 33° N. It should be noted that Summer Time in the British Isles commences on Sunday, April 10, at 2h.