If you divide the number of stars received by the volume in which they are (all volumes are approxi

Stellar density is the number of stars falling on the volume of 1 cubic parsec. The study of our solar system, you can start with a definition of the stellar density in the vicinity of the sun. First we get a rough estimate using Table. 1. Since the twentieth of the closest star is at a distance of 3.47 ps, the average stellar density in a sphere with a radius of 3.47 ps can be calculated by dividing 20 by the volume of the sphere. Obtained 0.11 stars per cubic parsec.
However, we can not be sure that within a sphere with a radius of 3.47 ps identified all the stars. electric chafing dish Probably, there are stars so low luminosities that, despite the closeness of their luster is very small and the apparent magnitude may be equal to 16-17 . But the star of such apparent magnitude of millions, and allocate them among the stars that are very close to us, it is extremely difficult.
To verify the correctness of the assumption that the closest stars are not fully understood, we will use a more extensive list of nearby stars, electric chafing dish composed in 1942 by American astronomer Kuiper. This list contains 252 stars identified within the sphere with a radius of 10.5 ns. Count the number electric chafing dish of stars is closer 6.63 ps, how many distance lies between 6.63 and 8.34, then between 8.34 and 9.53 and, finally, between 9.53 and 10.50 CA. Such distances we chose because of a sphere with radius 6.63, 8.34 and 9.53 ps divide the whole sphere with a radius of 10.5 ps into four equal-size. We can assume that the actual stellar density in all locations within a sphere of radius 10.5 ps is the same, so if the proportion of undetected stars did not depend on the distance in all four groups have been allocated the same number of stars. However, the relevant number of stars equal to 93, 66, 48 and 45. The result shows that in the near of four equal: the volume of the star revealed more fully than in the second, and the third and fourth volumes of the share on the range of identified stars continues to decrease. This, of course, to be expected.
If you divide the number of stars received by the volume in which they are (all volumes are approximately 121 ps 3), we obtain for each volume of the stellar density detected stars. It is equal to 0.077, respectively; 0.055; 0,040 and 0,037 stars on the 1 ps 3.
We use the findings to make up undetected stars. To do this, we construct a diagram (Fig. 2), in which the horizontal axis we plot the average distance of each volume, t. E. The radius of the sphere, dividing the volume electric chafing dish into two equal parts (small dashes upward from the x-axis) and vertical electric chafing dish the density of stars identified in this volume. After that, draw a straight line that passes as close as possible to those obtained four points. Direct gives the variation of the density of the identified stars, t. E. The visible stellar density, which decreases with increasing distance and is always less than the true stellar density constant in this volume. But it is obvious that the immediate vicinity of the Sun, we are able to identify electric chafing dish all the stars. Therefore, the value of the visible stellar density at a distance of zero, obtained at the intersection of the line with the vertical axis of the diagram is both a value of true stellar density. Count shows that it should be evaluated in 0,133 stars per cubic parsec.
The method used in addition to filling novyyavlennyh stars, has reduced the role of chance. If based only on the 20 nearest stars, the result is more susceptible to accidents as these 20 stars could randomly to stay closer or less than the average for the entire volume. Operating with 252 stars, we significantly reduce the impact of the event. On our diagram accident in the positions of the stars revealed that the points are not exactly on the line, and deviate from it up or down.
The article electric chafing dish is based on old data, so the output is different from reality almost 2 orders of magnitude. In the sphere with a radius of 3.47 ps is not 20 and 980 stars brighter than 13th magnitude. A sphere with a radius of 5 ps is 5287 stars. Indeed the nearest star from the sun is at a distance 1.438228103 SS, but then starts to increase the density of stars and to 4.5 PS becomes approximately equal to a constant 10-11 stars per cubic parsec. Your review
Categories Galaxy (61) Life in the Universe (13) Mysteries of the Universe electric chafing dish (34) Laws (6) Stars (33) Land (9) Space exploration (89) Tools of Science (4) Quasars (4) Cosmic forces (7) Space bodies ( 8) Space Theory electric chafing dish (19) Macro and microuniverses (3) Megaobekty space (5) metagalaxy (2) Meteorites (7) Science & Space (55) Unusual electric chafing dish events (8) Planets (20) Pulsars (1) radio emission (9) Other facts about space (9) Constellations (1) Sun (1) Satellites (13) Particles (2) Man in Space (1) Black holes (1) Pages Online Video Forum ISS Navigation
Archives electric chafing dish June 2014 April 2014 January 2014 December 2013 October 2013 September 2013 July 2013 June 2013 March 2013 February 2013 January 2013 December 2012 November