AstroNotes 1963 June Vol: 2 issue 06

EDITORIAL . Radio Astronomy for Amateurs (2) . Planets . Deep Sky . OBSERVERS' GROUP MEETING FOR JUNE . SETTING CIRCLES ( 1st part )

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AstroNotes

The Newsletter of the Ottawa Centre, RASC

Vol. 2    Issue 3  March 1 1963

Editor: George Brunton, 2565 Elmhurst    TA8-1473
Circulation: Howard Harris, 620 Keenan   PA8-604 4

EDITORIAL

Six members of the Ottawa Centre were noted at the General Assembly in Toronto this year.

Dr. Peter Millman gave a paper on Springhill Observatory and meteor observing, which was only one of the 12 excellent papers given ; Dick Tanner m.c.’d the first half of the paper session, and, to the delight of us all, Miss Miriam Burland received the SERVICE AWARD. Congratulations!!

Also representing the Centre were Dr. Ian Halliday and George and Dan Brunton.

Two out of town visitors have turned up at our meetings lately.

Constantine Papacosmas from the Montreal Centre spent a weekend in town, staying with Fred Lossing and attending the meeting of the Observers Group.

I hope Constantine enjoyed his visit as muchas we enjoyed having him.

Another visitor, but from much farther away, is P.A Miththapala from Ceylon. Mr. Miththapala first came to one of our meetings to tell us of the Ceylon Amateur Astronomical Association and to extend their greetings to the R.A.S.C. and to the Ottawa Centre in particular. His talk on the C.A.A.A. and of life in Ceylon was well received and since that day he has been an active, if temporary, member of the Centre. Unfortunately, he will be returning to Ceylon before we resume our regular meetings in the Fall, but I’m sure he will be able to join some of our impromptu star parties during the summer months.

Names and addresses of the Observational Coordinators for the Group may be found in any previous Issue of AstroNotes.

Radio Astronomy for Amateurs (2)

by Gord Grant

Concerning satellites, as we suggested in AstroNotes for March, the state of the art has become quite complex. With the great number of satellites now in orbit it is a full time occupation for many professional people to keep watch on them. Most satellites are now too small to be seen even in the best amateur telescopes. Radio tracking is therefore the only way to ”see" them. The information contained in their complex transmission signals requires very elaborate equipment for decoding, at a price usually f a r beyond the amateur’s means.

One satellite that is still in orbit and easily visible is ECHO 1, the aluminum-coated plastic balloon. It d i d carry atracking transmitter that is now silent and orbital elements must be extrapolated from visual sightings. The intention of ECHO 1 was to reflect Radio transmissions beamed at it so that communications would be possible over great distances. It was demonstrated to be possible but the results were marginal, even with the most elaborate receiving and transmitting equipment.

ECHO II, a larger-diameter balloon and orbiting at a lower altitude has been planned for some period of time and may be launched in 1963. Being larger it will be more easily seen and the increase in surface area is expected to provide reflections of Radio transmissions at frequencies as low as 50 mcs . On this basis, a number of devoted Amateur Radio Operators are hoping to communicate at frequencies of 50 mcs., 144 mcs., and higher up to distances of 3000 miles.

Amateur astronomers may be able to assist their amateur Radio friends at this time with calculations and predictions of the position of the satellite .

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Each sunspot is the Centre of a magnetic field which may be a l most a Million times stronger than that of the Earth.


Planets

by Bill Dey

Although Neptune is beyond the realm of amateur planetary work, many amateurs find satisfaction in locating it and following its path among the stars.

Neptune may be found in much the same manner a s was described for Uranus in the February Issue of AstroNotes. Start by becoming familiar with the stars in the southern sky in the early evening.

Alpha Librae, the key to finding Neptune, can be located with the unaided eye between the b Right stars Antares and Spica. Invert the star map and locate Alpha and Mu Librae in your finderscope. (Mu is 2 deg. or 4 moon dia. down from Alpha . )

When you are certain that you have found Neptune, use as high a power on your telescope as the seeing will allow to show its planetary disc .


Deep Sky

by John Stairs

Following the great bear, and directly overhead at this time of the year, is the k it e - s h a p e d constellation BOOTES ( pronounced beau-oh-teas ). It lacks any easy galaxies or clusters but d o e s have a number of excellent d o u b l e s . These stars are marked with a horizontal b a r in the drawing.

The data follows. Note that the position angle (P.A.) is the angle between the two stars measured clockwise from the north point around the brighter of the two.

Name          Mags          Dist ( " )   P.A.      not e s
kappa       5.1 / 7.2        13.2        237       white - blue
iota        4.9 7.5          38.4         33       yellow - white
39          5.8 6.5           3.3         45       fine contrast
44          5.2 6.1           2.6         24   8 Bin Per. 205 yrs.
Mu(")       6.7 7.3           1.8         36   Mu (1) d109 ” P.A. 171
delta       3.2 7.4         105.0         79       yellow - blue
epsilon     3.0 6.6           2.8        334       yellow - blue
xi          4.8 6.8           4.8         13       yellow - purple
pi          4.9 6.0           5.8        106       white - white
zeta        4.4 4.8           1.1        133     Bin Per. 130 yrs.
1835        4.4 4.8           6.4        190     Bin Per.  40 yrs .

Epsilon is a superb object but it is quite difficult in a 3 1/2 in. reflector .Kappa is very be a u t if u l . Xi and 39 each show f in e contrasts of c o l ours.

Not shown in the figure is a 6th magnitude globular cluster,  M 3, located on e deg. short of the half way mark on the line join in g Arcturus and Alpha in Canes Venatici (Cor Caroli ) . Cor Caroli is the brighter of the two stars about 12 deg. be low and r o u g h l y parallel to the handle of the Dipper.


OBSERVERS' GROUP MEETING FOR JUNE

The n e x t meeting of the group won’t be held until June 29th ., but this meeting will be a very special one. This month we have been invited to meet at Springhill Meteor Observatory .

Highlights of the meeting will be at our of the Observatory, a meteor it e d is p l a y, the all- sky cameras, and the radar installations . Bring your own telescopes. These may be s e t up on the l a w n where e l e c t r i c a l out l e t s are available . This promises to be a very interesting meeting, so don't miss it .

For this meeting we will meet at the early hour of 7.30 at the Geophysical Bldg., Experimental Farm . This is to allow us plenty of time to arrange transportation for those who do not have any . REMEMBER. . . . 7.30!!!


SETTING CIRCLES ( 1st part )

by Fred Lossing

The positions of astronomical objects a r e located in the sky by means of two coordinates: declination (dec.) and Right ascension (R.A.). These are equivalent to latitude and longitude respectively for positions on Earth. Declination is reckoned in degrees and minutes of arc (60 m in . equals 1 deg.) north and south of the celestial equator, the equator being zero and the north and south poles p l u s 90 deg . and minus 90 deg . Right ascension is e x p r e s s e d in hours and minutes (of time) counting from 0 hour at the first point of Aries around to your left as you face south, until at R.A. 24 hrs 0 min. the same point as 0 hour is again reached . Local sidereal time is the Right Ascension of the north - south meridian directly overhead at any moment.

As we will see in part 2, y o u do not need to know or to calculate the Local sidereal time ( or to have a telescope drive mechanism ) in order to use setting circles to locate a star, planet or Messier object whose R.A. and Dec. are known.

A pair of simple cardboard setting circles fastened to your axes with Scotchtape (or the equivalent) can give sufficient accuracy to locate an object with in a low power field ( a b out 2 deg. ), provided of course that y our telescope has an equatorial mounting. S u c h cardboard circles c an be easily made using a drawing compass and a d i m e -store protractor of an y size . Cut two 6" (or larger ) circles from heavy cardboard m a r k in g the e x a c t Centre carefully . Draw a diameter line through the Centre with a sharp pencil.

With the protractor (straight side on the line, Centres coincident) mark off each deg. around the circle for the dec. circle, and each 3 deg. for the R.A. circle . Project These m a r k s to the edge of the circle by drawing straight line s from the Centre through the marks . At the edge, using ink, mark each deg. on the dec. circle with a short line, and each 10 deg. with a l on g line . Number the 10- deg. line s from 0 deg. to 90 deg. to 0 deg. to 90 deg. to 0 deg.

On the R.A. circle each 15 deg. will be on e hour, and each 3 deg. will be 12 minutes . Finer subdivisions can be put in by hand if required, at every minutes for instance. The numbering of the hours on the R.A. circle from 0 to 24. may be either clockwise or counterclockwise, d e p e n d in g on whether the circle or the indicating pointer is fastened to the polar axis .

Leave the numbering until you have made a temporary installation to check this point.

The dec. circle should be fastened to the dec. axis (or the telescope ) and provided with a pointer fastened to the telescope (or the dec. axis ). When pointing to the north pole, the dec. circle should read 90 deg. The R.A.circle should be made m o v able with respect to the polar axis, for setting to given R.A.‘s, but the motion should be stiff enough so that it will not slip accidentally. A pointer should b e provided for the R.A. circle as well .