spaceweb@oulu.fi - last update: 1 July 1998, 1200 UT (RR) . ... Relates the wave number k to the wave frequency. ... From the equation of motion , m d v /dt = q( v x B ) one can calculate that, in a presence of magnetic field B , a charged particle is accelerated in direction perpendicular to both v (perp) and B . ... The angle a between magnetic field B and velocity vector of a charged particle, v ., i.e., sin a = v(perp) / v(total), where v(perp) refers to the velocity component perpendicular to B . ...

Next: Order definition: Method Up: Reduction using Standard Previous: Reduction using Standard . If DEFMTD is set to STD or COM , WIDTH1 is the width of a single echelle order. To find this value load the ORDREF on the display using LOAD/IMAGE and use for example the commands GET/CURSOR or EXTRACT/TRACE and PLOT/IMAGE TRACE . A superior method which will be needed later in the reduction any way is to extract a column and to produce a plot on the hardcopy device. ... PLOT/COL ima @x . ...

... The exact directions of the offsets are parallel to the rows and columns of the CCD on which the aperture is specified. ... It is often useful to explicitly specify the desired rotation of the WFPC2 field-of-view on the sky. ... Figure 7.8 shows the CCD orientation and aperture locations relative to the U3 axis. ... Obtain the Position Angle (PA) of the source axis on the sky, measured in the standard way, North through East. ... desired source angle in field-of-view measured CW from +U3 axis) . ...

... sin f = y / r . cos f = x / r . ... They are now viewed as new definitions of the sine and cosine, for the polar angle f given by x and y ( a slightly different way of formulating this definition is described further below ). ... sin 2 f + cos 2 f = 1 . ... Angle . ... Many trigonometry texts define the sine and cosine slightly differently, using the so-called unit circle . ... Then the distance AB ("the sine line") equals sin a , and the distance OA ("the cosine line") equals cos a . ...

... Bad Astronomy . ... I think I will break from my usual format of Bad Astronomy/ Good Astronomy by saying that the way we define seasons currently is not strictly bad, but I feel (in my opinion!) that it could be better. The definition of when the seasons begin is at the moment of solstice or equinox; that is, winter (in the north) starts on December 22 nd and summer starts on June 22 nd . ... Now imagine breaking up the Sun's 46 degree up-and-down yearly swing into 1 day intervals. ...

... Для определения потенциальных участников конференции информа- ция о ней распространяется по сети электронной почты "FidoNet", a также по другим каналам. ... Возможна связь с конференцией через "шлюзы" из других сетей электронной почты (Relcom, In+erNet, BitNet и др.), для этого необходимо воспользоваться адресами, имеющими возможность передачи информации из одних сетей в другие. ... Москва 127560, а/я 28, Центр SETI. Или по сети электронной почты: Igor Kuznetsov 2 : 5020/66 С FidoNet. ...

... Planets and Brown Dwarfs . ... Mission Definition . Ask anyone on the street to give an example of a planet, and they'll consider you a bit dim. ... Finally, if you ask "What is the exact scientific definition of 'planet'?", it turns out that nobody can answer it, because there really isn't one. ... The word itself means "wanderer" in Greek, and other cultures generally have words for "planet" with a similar meaning. So why isn't that good enough for us today? ...