Western Horizon Research Articles

ASPECT OF THE HEAVENS FOR JANUARY AND FEBRUARY, 1954

Mercury is in superior conjunction on January 14 and at greatest eastern elongation, 18° from the sun, on February 13. During the second week of February the planet should be visible just above the western horizon in the evening twilight. Venus appears too close to the sun to be easily observed now, being in superior conjunction on January 29. Mars is increasing in brightness as its distance from the earth decreases, its magnitude changing from +1-6 on January 1 to +0.8 on February 28. It is moving through the constellations of Libra and Scorpius, passing 1 ° south of Saturn on January 2 and 5° north of Antares on February 24. At that time it is rising about one hour after midnight. Jupiter, magnitude 2. 1, is in Taurus, ending its retrograde motion on February 10. At that time it is high in the southern sky during the early evening and sets about three hours after midnight. Table I lists the transits of Jupiter's satellites and their shadows, which can be observed at convenient times on the Pacific Coast.

Jupiter Still Prominent

0 WITH THE COMING of May, the planet Jupiter continues to be the most prominent star or planet visible in the evening sky. It is the first to appear in the northwest as the sky darkens after sunset. It then moves toward the western horizon to set-about four hours after sundown on May 1, two hours earlier on the 31st. Jupiter's position in the constellation of Gemini, the twins, is shown on the accompanying maps. These maps depict the sky as it looks about 11:00 p.m. (your own kind of daylight saving time) on May 1, 10:00 at mid-month, and 9:00 at the end. Among the stars, the most prominent is Arcturus, shown high in the south in Bootes, the herdsman. Below it is Virgo, the virgin, with Spica, another star of the first magnitude. Above and to the right of Virgo shines Leo, the lion, with a star of similar brightness, Regulus. Low in the southeast stands part of Scorpius, the scorpion. The star close to the horizon, named Antares, is also of the first magnitude. At such a low altitude, however, so much of its light is absorbed by the earth's atmosphere that it appears considerably fainter. In Gemini, where Jupiter now stands, is Pollux, another first magnitude star, and nearby are two others of the same degree of brightness. One is Capella, to the right in Auriga, the charioteer; the other is Procyon, toward the left in Canis Minor, the lesser dog. These stars shine brilliantly in the winter evening sky, but are not visible on summer evenings. To take their place, however, two stars are rising in the northeast that will become very prominent on summer evenings. One is Vega, in Lyra, the lyre; the other is Deneb, in Cygnus the swan Like Antares, which will also become more conspicuous in summer evenings, Deneb is considerably dimmed because it is so low on the horizon. High in the north shines Ursa Major, the great bear, which includes the familiar Big Dipper. Here are the two pointers, whose direction indicates the north star, Polaris, which is part of Ursa Minor, the little bear-and also of the Little Dipper.

ASPECT OF THE HEAVENS FOR MAY AND JUNE, 1946

Mercury is in superior conjunction on May 31. During the last week of June it should be visible in the evening twilight just above the western horizon. It is in conjunction with Saturn on June 23, passing 1 ° 30' north of it. Venus is a brilliant object in the evening sky, setting about two hours after the sun. Its conjunction with the moon on May 2 at 18h 30m will make a beautiful sight in the evening sky, Venus being 2° north of the crescent moon and Aldebaran 5° to the southeast. On June 1, a daytime occultation of Venus is visible in the extreme western part of the United States. At the standard station (36° N, 120° W), about halfway between Los Angeles and San Francisco, immersion occurs at 15h 43m and emersion at 17h 02m. On June 12, Venus passes 2° north of Saturn.

The Night Sky in November

THE moon is new on November 11 at 7·9h. and full on November 26 at 21·9h. U.T. The bright star λ Geminorum (magnitude 3·6) is occulted on November 30, the disappearance as seen from Greenwich taking place at 2h. 22·8m. at position angle 102° from the north point, and the reappearance at 3h. 37·8m. at 282°. Mars, Jupiter and Saturn are bright planets in the evening or night sky. In mid-November, Mars souths at about 18½h., Jupiter at 20½h. and Saturn at 22¼h. Jupiter is in conjunction with the moon on November 21 at 22h. and Saturn on November 24 at 1h. Uranus is in opposition on November 13, when its distance from the earth is nearly 1,731 million miles. Neptune, near the border between the constellations of Virgo and Leo, makes a near approach (about 20″) to the eighth magnitude star BD + 3° 2549. At about 21h. in the middle of the month, the Milky Way passes from the eastern to the western horizon through the zenith of London. The most distant celestial object that can be seen with the naked eye—the Great Nebula in Andromeda—is on the meridian at an altitude of 79°. Vega is the brightest star in the north-west quadrant of the sky and Capella the brightest in the north-east. The Pleiades cluster is well above the eastern horizon, and Orion is then just rising. The Leonid meteors should be looked for about November 14–16; their radiant point, preceding γ Loonis, rises about 23h. The meteors of this well-known shower are characterized by swift flights and their greenish colour. Light variations in the variable star Algol (β Persei) may be noticed about one and a half hours before and after the following times of primary minima: November 14d. 3·1h.; 16d. 23·9h.; 19d. 20·8h. and 22d. 17·6h.

Auroral display of July 3, 1939

On July 3, 1939, at 21h 30m (75° west meridian time), a splendid display of Northern Lights was visible at Bridgeport, Connecticut. Long streamers of light stretched from the eastern to the western horizon almost 180° in length, from 40° above the northern horizon to 30° beyond the zenith into the south. The ten bands of light were unusually straight through their entire length, quite regular in width, and nearly uniformly spaced. There was a bright Moon and the sky was cloudless. The stars shining through the uniform bands of light gave the aurora the appearance of the American flag.

Convergent Sunbeams

I CAN add to the correspondence on the above subject in NATURE of February 19 and March 26 by reporting that I have observed the phenomenon on numerous occasions at Diyatalawa, a village at an altitude of 4,000 ft. on the eastern side of the central hills of Ceylon. The western horizon about eight miles away is the edge of a block of rough mountainous country with many peaks of about 7,000 ft. altitude (including the well-known Adam's Peak). During the clear weather of spring and summer, I frequently observed the shadows converging on the eastern horizon at sunset, and I used to wonder if they could be produced by prominent peaks as well as by clouds.

The Night Sky in June

ON June 21 at 20h, the sun enters the sign Cancer (the summer solstice). In the latitude of London, the length of night from sunset to sunrise is then only 7h 26m. The moon is new on June 8d 20-7h and full on June 23d 23-0h. On June 8, a total eclipse of the sun takes place and is visible in equatorial regions of the Pacific, but although the path of totality (of maximum breadth 153 miles) extends over nearly one hundred degrees of terrestrial longitude, there are very few possible land sites to which expeditions can be sent. The duration of totality at the noon point is 7m 4s, making this eclipse the longest that has occurred for more than a thousand years. Of the planets visible during June, both Mercury and Venus are morning stars. On June 6, Mercury is at greatest elongation 24° west, and Venus at greatest western elongation (46°) on June 27. Venus is in conjunction with Uranus on June 18 at llh, when the two planets are separated by 2-7°. Mars is conspicuous low in the south as the sky darkens. The planet decreases in brightness from magnitude 1-7 to 1-2 during the month. On June 20 at llh, Mars is in conjunction with the moon and is then only 0-1° northwards of the latter (geocentric positions). The circumstances produce an occultation of Mars by the moon, the phenomenon not, however, being visible from the northern hemisphere. Jupiter rises in the evening twilight and souths about 2h in the middle of the month; on June 25 at 2lh it is in conjunction with the moon. Saturn rises soon after midnight in mid-June; on June 4 at 2h conjunction occurs with the moon. The apparent breadth of the minor axis of the ring system is 3° 4′. At 22h in mid-June, the bright star Regulus is nearing the western horizon; Arcturus has passed the meridian, Sjr ica and Antares are low down in the south, while Vega, Altair and Deneb are conspicuous eastwards of the meridian. The maximum of the Scorpiid meteors is due about June 4, the radiant point being nearly midway between a Scorpii (Antares) and Y] Ophiuchi. An ephemeris for the comet Grigg-Skjellerup, is given in the B.A.A. Handbook as follows:

Studies of the corpuscular component of the cosmic radiation

Evidence of the corpuscular nature of the primary cosmic radiation is found both in the geographical and in the angular distribution of its intensity. In his study of auroral phenomena Störmer (Zs. Astrophysik, v. 1, p. 237, 1930) obtained a solution for the orbits of charged particles projected from outside into the magnetic field of the Earth and he, as well as Rossi (Nuovo Cimento, v. 8, No. 3, pp. 3–15, 1931), have pointed out the application of this solution to the distribution of the cosmic‐ray intensity. Störmer's equation shows that for rays of electronic mass and of a particular energy, unless this be above 1010 volts, there is an inaccessible equatorial zone on the surface of the Earth into which no ray can enter regardless of its initial position and direction. On either side of the inaccessible zone are zones only partially accessible to rays of the energy in question since here these rays may reach the Earth's surface only on orbit's which lie within a cone of limited aperture. At the edge of the inaccessible zone this cone opens up with infinitesimal aperture in the direction of the western horizon for positive rays and towards the eastern horizon for negative rays, but as the point of observation is moved to higher latitudes the cone of possible orbits opens up continuously and eventually fills the entire sky. As an simple, the surface of the Earth at the equator is completely inaccessible to rays of energy less than 1010 volts and is completely accessible only to rays of energy greater than 6×1010 volts. The 45° parallels, on the other hand, begin to be accessible to rays of energy 3.3×109 and are completely accessible to rays of energy greater than 4.9×109 volts.

The Sky in October

OCTOBER will be a favourable month for seeing most of the planets. Mercury will be visible as an evening star—it reaches its greatest eastern elongation on October 28, when it will set an hour and a half after the sun. Without a telescope one can only conveniently see Mercury on these occasions of eastern elongation—choose a site with a good view of the western horizon and keep a sharp look-out just after sunset. Venus will also be visible in the evening sky. At the end of October this planet will set three hours after the sun. It will be a brilliant object (the stellar magnitude will be—3-8). On October 14 there will be a conjunction of Venus and Mars. Actual conjunction takes place at 11 hours, that is, in broad daylight, but the close positions of the two planets just after sunset on the following evening should form an interesting sight, especially if Mercury is seen as well. Jupiter will only just have passed its conjunction with the sun, and so will be invisible, but Saturn will again be visible in the southern sky throughout the night. Finally, Uranus will be in opposition on October 19.

Aurora Display and Magnetic Disturbance

ON Saturday evening, Dec. 20, at about 18 h. 35 m., I noticed that the sky was strongly illuminated along the northern horizon, the light extending about 40° in azimuth, with its centre, as near as could be estimated from the position of the pole star, true north, and a maximum altitude of about 15°. It was at once suspected as an auroral arch, but as the magnetic curves which had come off that morning showed the magnetic conditions to be exceptionally quiet, some doubt was felt as to the auroral character of the light. A suspicion was entertained that it might be due to the illumination of a sheet of very high cloud, though the sun was far below the horizon. This, however, appeared unlikely, both from the length of time after sunset and from the fact that there was no illumination over the western or north-western horizon.

Rainbow Visible after Sunset

IT may be of interest to record that about sunset on Monday, June 4, there was a fine rainbow here which persisted until the sun was well below the horizon. The last trace of it vanished at 20h 11m G.M.T., at which time the altitude of the true sun was approximately minus 1° 30prime;. Making a generous allowance for refraction, this would still put the upper limb of the apparent sun very appreciably below the horizon. This is perhaps the more remarkable in that there was a low bank of cloud along the western horizon. The great altitude of the top of the bow was very striking, and it did not, of course, reach down to ground level, but faded out at a considerable height, which there was not time to measure. My longitude and latitude were 4m 28s E., 51° 21′ N.

Our Astronomical Column

LARGE METEOK ON JAN. 9, llh P.M.—Mr. W. F. Denning writes: This very large meteor was seen by an observer when motoring about 6 miles east of Birmingham. The terminal portion of its flight was from near the star Sirius vertically to the horizon. The object was much brighter than Venus at its best, and the nucleus threw off a dense train of sparks at the end. The same meteor was noticed from Ilford, Essex, where the path was recorded as moving from just below Rigel and K Orionis in a direction towards the western horizon. It was very brilliant, and gave an outburst of sparkling material.

THE CONSTELLATION ORION

An article in the June number of these Publications gave a short description of Scorpio, one of the most prominent of the constellations of our summer evening sky. There is a certain degree of propriety in making Orion the subject of the next sketch in this series, for it is one of the best known and most brilliant configurations in the winter evening sky, and is, further, associated with Scorpio by the relationship of avoidance. Orion disappears at the western horizon as Scorpio rises in the east, a fact which the ancient mythologists explained as due to the mighty hunter's fear of the scorpion by whose sting he was slain. Even though translated to the skies he still flees from his venomous pursuer. Orion is always pictured as a giant wielding an uplifted club, with one hand and, in lieu of shield, holding a lion's skin over the other arm. In Bayer's Uranometry (1661) the club is held in the left hand, but the more familiar drawing is the one here reproduced from Flamsteed's Atlas Coelcstis (1729). The hunter faces the gigantic bull, Taurus, whose head and shoulder are indicated by the Hyades group, and the cluster of the Pleiades, and is followed by his faithful dogs Canis Major and Canis Minor, marked, respectively, by Sirius, the brightest, star in the sky, and Procyon, another star of great brilliance. Figure 1 gives an outline of the entire constellation, but when we think of Orion we generally have in mind only the region outlined by the four bright stars Betelgeuze (a), in the giant's right shoulder, Bellatrix (γ), in his left shoulder, Rigel (β), in his left foot, and Saiph (κ), in his right knee. Within this quadrilateral are the bright belt stars, the little line of stars in the hunter's sword, and also the richest parts of the great

Correlation of the Tertiary Formations of the Great Plains 1

Introduction The following discussion is intended to present the currently accepted correlation of the standard succession of western Tertiary mammal horizons, with an attempt to distinguish between its fixed and well proven features and those which are in varying degree doubtful or provisional, or in which recent evidence appears to indicate certain modifications. It is hoped that this method of presentation may be of aid in reconciling the evidence of the vertebrate faunae with that of marine invertebrates and plants. It is also necessary to discuss the criteria used in the methods of comparison, necessarily based on certain underlying assumptions which may not always be even approximately true. Summary of Criteria in Correlation 1. Direct superposition (in beds not overturned) is the fundamental evidence. 2. Stratigraphic continuity of lithologically similar strata or sequences of strata is usually, but not always, evidence of identical age. A certain type or sequence of . . .

株虹

Kabunizi is usually observed standing on the horizon opposite to the sun at sunset. It is merely a phenomenon caused by the scattering of beams of light in air when they are projected into, through the openings between cumulus clouds on the western horizon at sunset. Seamen often regard it as an omen of coming storms. The author observed it with special interest since 1920.As far as the author observed, the phenomenon appears in July, August and September only, It is not certain that it can be regarded as an omen of storm The phenomenon was rather short in duration and usually disappears after half an hour or so.

The Aurora Borealis of March 22–23, 1920, as seen at the Cheltenham Magnetic Observatory

Another magnetic storm of extraordinary magnitude was recorded on March 22–23, 1920, at the magnetic observatory of the United States Coast and Geodetic Survey, Cheltenham, Maryland, latitude 38° 44′.0 N., longitude 76° 50′.5 W. Its chief features are described in Mr. Hazard's article, pages 57–59. There was no recurrence of the storm 27 days later, April 19–20.The Aurora was visible soon after sunset on March 22, 1920, but was first noticed by the writer at 8h 05m 75th meridian time. At 8h 10m a display of rays developed, proceeding from a bright band low in the northern horizon some 45° in extent. The rays were visible from a point in the western horizon a few degrees (5°–10°) N. of the new moon (azimuth from S ‐ 88°) to a few degrees in the eastern horizon east of Arcturus (azimuth = −76°.0), and apparently converged to a few degrees north of the planet Jupiter (azimuth 26.5 and altitude 68°.5). There was a conspicuously rosy colored ray in the east. The rays lasted for about 5 minutes. The boundary of the illuminated area was parabolic in form. The ray display was followed by a general diffused glow.

Northern lights in the North Pacific Ocean Sept. 23, 1909

Sept. 25th, 1909 at 3 A.M.; Latitude 51°16′ N., longitude 134°40′ West of Greenwich.A whitish sheet of light appeared in the northwest horizon, extending from the star Vega (setting) through Ursae Majoris. This was followed by shafts of light about 2° or 3° in width, appearing simultaneously in the eastern and western horizon, finally creeping up and meeting an the south, passing sometimes through the constellation of Orion, covering the planet Saturn and passing north of Mars, at other times passing through Sirius and covering or extending south of Mars, imparting a marked brilliancy to said and neighboring stars. After 4:00 A.M. Northern Lights appeared from north to east of a reddish and green hue, assuming rainbow colors at times. Barometer was 30.04 inches; air 50°, wet bulb 47°, water 50° Fahrenheit.

Sun Columns at Night

A REMARKABLE phenomenon, similar to that which I described in 1888 (NATURE, vol. xxxviii. p. 414), was witnessed by me on the evening of March 13. At 7h. 7m. p.m. I saw on the western sky five silvery white columns coming evidently from the sun, which set at 6h. 1m. The columns extended over the whole sky, and, like meridians on a globe, converged to a point in the eastern sky, which was about as high above the eastern horizon as the sun was below the western horizon. The sky was full of stars, a powerful wind having swept it clear; and at 7h. 25m., fifteen minutes before complete night had set in, the rays still reached the zenith. The rays cannot be straight sun rays, for the calculation of the height of the atmosphere by Alhazen's method would yield an abnormally high value, and they could not meet in the east, like meridians, but they must be curved and pass along the upper strata of the atmosphere. This is either due to reflection, or, more probably, the phenomenon is one of an electrical nature, similar to that described in NATURE of March 12 (p. 437), which has just reached me, by Dr. O'Reilly.

A Rare Phenomenon

ON a visit to Dunecht, I was just leaving the Observatory about 11.18 G.M.T. on the 10th inst., when I saw a sharply-defined straight streak of light arching the sky from east to west. It was about 1° in width, and of uniform brightness from side to side, but more intense towards the western horizon, where it disappeared behind the trees at an altitude of some 4°. Eastward it extended across the constellation of Andromeda, near the girdle, quite beyond the convergence point of auroral rays, or fully 120° from the western horizon. This much I saw, but cannot say if the streak passed north or south of the Great Nebula.

Japanese Clocks.

WITH reference to your notice of the Japanese clocks purchased for this Museum, and described by Mr. A. Rambaut, it may prove of interest to point out in somewhat fuller detail the conclusions at which he has arrived as to the cause of the peculiarities in their construction It was on account of these, to me, unintelligible peculiarities, that I invited Mr. Rambaut to undertake their explanation, and this, I venture to think, he has very thoroughly accomplished as follows. The three clocks agree in having a dial on which the time is indicated by a pointer attached to, and descending with, the weights. In other respects they differ, though all are made more or less on the same principle. The largest of the three appears the most important, and the greater part of the paper is occupied in explaining its construction. The dial of this is divided by vertical lines into six equal spaces, which are crossed by a series of thirteen graceful curves. An examination of these curves leads to the conclusion that they were intended to divide the day and night, at all seasons of the year, into six equal portions each. This system was common enough in ancient times, but the peculiarity of these clocks is that they show the day to have been reckoned, not from sunrise till sunset, but from the first noticeable streak of morning twilight until the sun had reached a corresponding distance below the western horizon. This distance is equal to 13°, and the form of the curves leads to the conclusion that the clock was constructed in a latitude of about 34° 7′, very little less than that of Miako, formerly one of the principal cities in Japan. An examination of the two other clocks, although they differ very much in detail, supports the conclusions derived from a study of the first.