Evening star. [volume] (Washington, D.C.) 1854-1972, 1902-11-29

| the opinion of Sir Norman Lockyer. this
| star is not a massive, sun-like body, but is
| simply dense and condensing swarm of
| meteortes. As the meteors condense the
| star will grow hotter and brighter; 1t will
| eventually become q sun, but such is not its
| condition at the present time, according to
| Lockyers theory. The observation of Mr..
| Packer is said 20 have been confirmed by
| Mr.. J. E. Gore.
| The Distance of Sirius.
| By means of the spectroscope the velocity
| of the movement of a star in the line of
sight-that is, toward us or from us-can
be determined with a very high degree of
| accuracy. Upon this capability of the spec
| troscope has been based a new and very
simple method of determining star dis
tances, which seems likely, where the cir
cumstanCes render it available to be much
| more reliable than that which has hitherto
been employed. The result of applica-
| ton of this method to the of Sirius has
| recently been published by Mr.. w. S.
Adams of the Yerkes observatory. Sirius
| is binary star, having faint green com
panion which revolves about the principal
| star In a period of about forty-nine years,
| or rather the two stars revolve in this
| period about their common center of gray
| ity. From a series of Photographic obser-
| vations made by Mr.. Adams between De-
| cember Is, 1901, and March IL, 1902. COM
| bined with results obtained by DIR. Nogel
| in 1890, It has been possible for Mr.. Adams
| to determine the velocity of the orbftaI
| movement Of the principal star, and there
| fore the size of the orbit. The actual size
! Of the orbit being known, Ii is simple
| matter to determine from it's apparent size,
| as this has been ascertained from the mi
| crometrical measurements, how far away
| the star is-on the principle that the far
| Their away an object is the smaller Ii APP
| pears to be. Mr.. Adams has brought out
| as a result of his calculations that Sirius
is distant from about fifteen light
| years" This is considerably In excess of
| the distance which has lately been given
for this star, based on the measures of DR..
Gill, namely, about nine light years.
Intensity of Sky Light.
In a recent number of the Journal of
the British Astronomical Association Mr..
Garvin j.. Burns describes a method en-
| ployed by him to determine the intensity
| OF the light received from the sky a
| clear, moonless night. He'says: The re-
suits obtained were discordant, but indi-
Gated that the total light received from
| one hemisphere is roughly that given by
| 1000 stars of the first magnitude. AS
| has already been stated in these columns.
| Prof. Simon Newcomb and Mr.. j. Il. Gore
| have each recently dealt with the same
| problem. The former reached the conclu-
| sion that the light of all the stars com
| bined, visible and invisible to the naked
| eye, equals that of 600 or possibly 500 stars
| the brilliancy of Capella while the latter
| fixed the light more definitely as that or
| $50 stars of the zero magnitude. A star
| of this magnitude is two and half times
| as bright as one of the first magnitude.
| Mr. Burns estimate-equivalen to 400 zero
| stars for each hemisphere-is in very close
| accord with that of Prof. Newcomb. he
| thinks it probable however that this sky
| light does not all come from stars, but may
| be partly solar light reflected from particles
| of meteoric dust.
Interstellar Space.
Astronomers are inclning more and more
| to the belief that apart from the ail-per-
| vading luminiferous ether, the precise ma
| ture of which one processes to under
stand interstellar space is perVaded
| throughout by matter in the form of eX-
| cessively rariied gases, the prevalent gases
| being most probably hydrogen, helium and
| the newly discovered constituents of the
| earth's atmoSphere-neon, krypton, etc.
| These gases all have a low density and
| are the last of the so-called permanent
! gases to have been liquefied in the low
| temperature experiments of the last few
| years. The proportion in which the various
| gases that form the earth's atmosphere, in
| Guiding water vapor, exist at different
| heights above the earth'S surface, must be
| determined, says Prof. Dewar by the dem
| stiles of the gases or to use a term which
| will be more generally understood, the rela-
| tive weights of a given volume OF the
| gases. BY far the larger part or the edrth
| atmosphere is within forty miles of the
! surface In it's lower strata the heavier
| gases must be proportionatey the more
! abundant The upper strata doubtless con-
| sst mainly of hydrogen, helium, etc, to
| which it is impossible to assign any limit.
The Planets.
| Mercury will be in superior conjunction
| with the sun-direetly behind the sun-on
| the 18th. After that date 1t Will be an
evening star, but it will not become visible
| until about the beginning of next month
| Venus has been an evening star since
| November IS. but will not become visible
| for several weeks.
| Mars is morning star. near the western
| border of Virgo. rising on the first of the
| month at about l am At the close OF the
| month it will be some y degrees farther
| east and will rise at about 11:40 pm.
| Jupiter is still an evening star, but sets
| on the first of the month at about $3.50
| pm Saturn sets about an hour and half
! earlier. Uranus will be in conjunction with
| the sun on the 14th of the month and
| NEPTUNE will be in opposition to the sun,
| crossing the meridian at midnight, on the
| oath.
On the 22d at 1 pm, Washington mean
| time the sun will enter Capricorn and
! winter will begin.