5 6 4 



NA TURE 



[September g, 1922 



Our Astronomical Column. 



August Meteors. — The great shower of August 

 Perseids was not well observed this year in con- 

 sequence of cloudy weather and moonlight. A rich 

 display of Cygnids was, however, witnessed during 

 the last half of the month from the point 291° +50° 

 near Cygni. The individual members of this stream 

 were brilliant with swift motion and short paths. At 

 the end of their flights many of them burst with a 

 sudden acquisition of brightness. The shower is 

 fairly well known and gave an abundant display in 

 1893'. I n tnat year, between August 4 and 16, 28 

 of its meteors were seen at Bristol, while 40 were 

 recorded by Mr. Corder at Bridgwater, and 30 by 

 Mr. Blakeley at Dewsbury. A full description of the 

 shower appeared in the Observatory for September 

 1893, and the explosive character of the meteors was 

 specially pointed out. The visible strength of the 

 shower varies from year to year, but its period has 

 not yet been ascertained; further observations are 

 required of this particular stream, for it is certainly 

 one of the most important of the many systems 

 which are in contemporary activity with the well- 

 known Perseids. 



Mars. — The first drawings of Mars at the present 

 apparition are published in L'Astronomie for July. 

 They were made by M. Mentore Maggini at Catania. 

 One, made on May 23, accords with the description 

 of M. Jarry-Desloges of the paleness of the dark 

 markings at this period, presumably due to their 

 being covered by a veil of mist or dust. This seems 

 to have dissipated by June 1, a sketch on that date 

 showing these regions dark, especially Syrtis Major ; 

 the southern end of it is flanked by two brilliant white 

 patches. Nepenthes is very prominent, and widely 

 double. The drawing indicates 15 other canals. 

 Both polar caps are shown, the southern being the 

 larger. Dr. Fountain in the B.A.A. Journal for 

 June 28 ascribes the red colour of the Martian deserts 

 to ferric oxide, and suggests that owing to the escape 

 of the lighter gases the Martian atmosphere may be 

 relatively rich in oxygen, so that meteoric dust would 

 tend to become oxidised. 



The Frye Reflecting Telescope. — The 100-inch 

 Hooker Telescope is not long to remain the largest in 

 the world. Mr. T. S. H. Shearman, Government 

 Meteorologist at Vancouver, has successfully cast a 

 speculum of 10 feet diameter and 50 feet focal length 

 which is to be erected in the new observatory planned 

 by Mr. Chas. H. Frye at Seattle. This observatory 

 is to be open to the public at certain times ; the 

 telescope will then be used in a horizontal position, 

 being fed with light by a plane mirror ; but when it 

 is employed for the photography of nebulae or other 

 faint objects it will be pointed directly at the sky. 

 The cost of the instrument is in the neighbourhood of 

 300,000 dollars, and is apparently being borne wholly 

 by Mr. Frye. The above particulars are taken from 

 Circular No. 1 of the Frye Observatory, which also 

 states that Mr. Shearman expected to make the first 

 astronomical observation with the new speculum 

 before the end of July. 



Variable Stars near M. 53. — Dr. Baade gives in 

 Mitteilungen der Hamburger Sternivarte, Bd. 5, No. 16, 

 an account of a photographic search for variables 

 near the globular cluster M. 53. It resulted in the 

 discovery of 7 variables within a region extending 

 from R.A. 13 11 i" 1 to I3 h 13'", and from Decl. 4-17° 39' 

 to +19 41'. Five of them are of the cluster type, 

 with periods between £ and f of a day. Applying 



NO. 2758, VOL. I IO] 



Shapley's rule for the absolute magnitudes of these 

 stars, their distances, in units of 1000 light-years, are 

 16, 20, 23, 41, 62 respectively. The last named, the 

 mean magnitude of which is 16-25, appears to be a 

 member of the globular cluster, though distant 34' 

 from its centre. The others are probably unconnected 

 with the cluster. Since the latter is in galactic 

 latitude 79 , the results suggest a much greater 

 extension of the sidereal system in this direction than 

 that indicated by Prof. Kaptevn, who concluded that 

 the star-density became sensibly zero at a distance 

 of some 10,000 light-years towards the galactic 

 poles. 



Abbreviations of Constellations' Names. — In 

 the printing of Star Catalogues in which reference is 

 made to the names of the constellations, a large 

 amount of valuable space is wasted in consequence of 

 the lack of a standard system of an abbreviated 

 nomenclature. At the meeting of the International 

 Astronomical Union held at Rome in May last, the 

 Commission on notation, units, and economy of 

 publication decided on a system of abbreviations 

 which involve only three letters for each constellation. 

 Thus, to give a few examples, And is Andromeda ; 

 CMa, Canis Major ; CVn, Canes Venatici ; Gem, 

 Gemini ; etc. In the Harvard College Observatory 

 Bulletin, No. 771, it is stated that this system will be 

 adopted forthwith. It is expected that it will now 

 be used universally, since it is a great economy and 

 convenience in printing, especially when large cata- 

 logues of stars with their magnitudes, positions, proper 

 motions, spectrum types, parallaxes, etc., are in 

 hand. 



New Nebul/e. — In the Harvard College Observa- 

 tory Bulletin, No. 773, it is announced that Mr. 

 Donald H. Menzel has found recently approximately 

 two thousand new nebulae on ninety photographs 

 made with the 24-inch Bruce telescope at Arequipa, 

 the southern hemisphere station of the Harvard 

 College Observatory. Most of the new objects are 

 south of declination — 45° : their positions and 

 descriptions will be published later. Of the eight 

 hundred brightest nebulas found by Mr. Menzel, about 

 thirty-five per cent, appear to be spirals, i.e. they 

 show spiral arms or the characteristic spindle form. 

 The majority of the other bright objects are stated 

 to belong probably to the type designated by Hubble 

 as globular nebulae. It is interesting to note that the 

 total number of nebulae now recorded is nearly 

 20,000. 



A Very Massive Star. — Much attention is now 

 being given to the determination of the masses of 

 stars, so that any star of excessive mass becomes at 

 once an interesting object. Dr. J. S. Plaskett, 

 Director of the Dominion Astrophysical Observatory 

 at Ottawa, describes (Mon. Not. R.A.S., vol. 82, 

 p. 447) the star B.D. 6° 1309, No. 2422 of the Harvard 

 Revised Photometry, which consists of two very 

 bright Oe stars, i.e. stars at nearly the highest tempera- 

 ture, 10,000 light years away from us ; they revolve 

 around one another in an elliptic orbit in a period of 

 14-414 days, but are separated by a distance of 

 90,000,000 kilometres. The brighter of the two stars 

 has a probable mass of at least 86 times that of the 

 sun, a density of o-oi, and an absolute magnitude of 

 — 5-65. The fainter star has a mass of 72 and is of 

 the same density, its absolute magnitude being —5-4. 

 The absolute magnitude of the svstem as a whole is 

 -6-3, which is the greatest so far determined. 



