ASTRONOTES Vol. 2 March Issue 3

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2 ASTRONOTES Vol. 2 March Issue 3 Editor: G.P. Brunton, 2565 Elmhurst TA Circulation: H.M. Harris, 620 Keenan PA ************************************************* The American College Dictionary defines the word "Observer as one who regards with attention so as to see or learn something, who makes or takes an observation, who watches, views or notes for some scientific or other special purpose. Now, how many of the Observers Group feel that from an astronomical viewpoint, they can consider themselves Observers during these last couple of cold months? Several of the Planetary coordinators have been knocking themselves out to prepare observing guides with the hope of stimulating activity during the winter nights. So far, four of the younger student members of the group have been showing up the remainder of us with their steady observing this past month. Larry Moran, Peter MacKinnon, Les MacDonald and Dan Brunton have been meeting every weekend at one of their homes for an evening of observingand shivering. Their luck has not been too good as each evening has been mostly cloudy, but some interesting bits of observing were done. In use are Pete s 3" reflector, Dan s newly completed 6 reflector, Larry s 1.4 U nitron and Le s 2.4 Polarscope. * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * OBSERVATIONAL COORDINATORS: Comets, Meteors Stan Mott PA Deep Sky John Stairs SH Instrumentation Fred Lossing RE Planetary Bill Dey RE Radio Astronomy Gord Grant RE Satellites Jack Horwood RE Solar Dave Fisher RE * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *

3 Radio Astronomy for Amateurs by Gord Grant One of the advantages of Radio Astronomy over visual astronomy is that the work usually can be carried on in the comfort of the indoors in any weather. We hope to discuss briefly in the next few articles some of the things that amateurs are doing and can do with modest outlays of equipment. One of the simplest of radio telescopes consists of a high frequency receiver (2 to 30 mcs) with almost any type of antenna. The observations made on the early Sputniks were done with such equipment, a type commonly found in any Amateur Radio Station. Indeed, Radio Amateurs were ideally equipped when 1957a was launched and made many valuable observations and records in the early days of its flight. Considerable information about the orbit and period can be derived from these observations. Predictions of next pass and measurement of the rate of change of period could also be made. The equipment is simple and readily available. Lenn Orr made one of the first tape recordings of 1957a using an inexpensive receiver. With the advance of the art, satellites have become sophisticated to the extent that they no longer use frequencies in the HF range (2 to 30 mcs). The same work may be done however but a little more care in the selection of a receiver must be made. Most satellites, American at least, carry a tracking transmitter on 136 m cs. Equipment for this frequency can be constructed by consulting a book such as the AARL Radio Amateur's Handbook. ************************************************ Gord Grant tells us that he has finally finished his observatory and has decided to name it "Steinview". He would be happy to show it to anyone interested. Those curious as to the name (or in need of groceries) can visit Gord for a good view - of the local Steinberg's!!

4 Deep Sky by John Stairs The beautiful galactic clusters in Gemini and Auriga (see chart) are almost overhead and well placed for observation with binoculars or telescope. The slightly modified N.G.C. summary descriptions are: M35..6th mag., diam. 29, considerably rich, pretty compressed, stars 9 to 16 mag. M36..6th mag., diam. 16, bright, very rich, little compressed, stars 9 to 11 mag., and scattered, distance 41,000 light years. M37..6th mag., diam. 24', pretty compressed in the middle. M38..7th mag., diam. 18', very rich irregular figure diam. 50", much compressed, very rich, irregular triangle shape. This is right beside

5 M35 but it requires a telescope and a clear dark night to be seen. Also nearby and easily seen on a dark night is M1, the Crab Nebula, of 10th magnitude. It is very close to the star at the tip of the lower horn of Taurus. The N.G.C. description: very bright, size 6'x4' extended 135 deg. position angle, mottled appearance, a little brighter in the middle. The largest of the Asteroids, CERES, can be easily followed with binoculars during the next three months (see chart above). From now until the end of March its magnitude is 6 1/2 and not until May does it diminish to 7, reaching 7 1/2 by mid-june. Its closest approach, 148 million miles, is on March 3 with opposition 5 days later.

6 Also in this area, as shown on the chart on the preceding page, are two more interesting galaxies. The N.G.C. descriptions are: M65..10th mag., size 8 ' x 2', much extended 165 deg, position angle, gradually brighter to the middle, bright nucleus. M66..9th mag., size 8 x 2 ', much extended 150 deg. position angle, much brighter in the middle, two stars north preceding. * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * MEETING OF THE OBSERVERS' GROUP The monthly meeting of the group will be held Saturday, 2 March, at 8.00 p.m. in the Geophysical Building. Members are reminded that guests are welcome. Bring along that neighbour that thinks you are slightly touched to observe in this weather. He might get the 'bug' too. * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * Solar Drawings by Dave Fisher If one wishes to obtain the approximate solar coordinates (latitude and longitude) of a sunspot, group or what have you, it is necessary to know the orientation of the Sun s axis and equator. This article explains how to fix them on a projected drawing of the sun.

7 The Observers Handbook on page 60 shows 3 columns P, B and L, figures for every 5th day. (The P is defined as the position of the solar axis measured in degrees toward the east from the north point of the sun s image. The northsouth line (not the axis necessarily) is perpendicular to the east-west line. The path traced out by the sun and all its surface features as it moves through the sky is in the east-west direction. If one were to mark successive portions of a single group of spots as the sun drifted across the field of a stationary telescope, and joined the marks up, he would have an east-west line on the sun. If a line through the centre of the drawing parallel to this east-west line were drawn and a line drawn perpendicular to this line, one would have the north-south line on the sun. If now one measures off the prescribed angle (column P in the Handbook), say 20 degrees, he would have the axis of the sun. Now draw in the east-west line on the sun (o), perpendicular to the axis to intersect the limbs of the sun, (i.e. roughly the equator). The angle B gives the latitude of the geometric centre of the sun, marked (o) on diagram 1. If as in diagram 1, B is positive, the north pole is dipped towards us and the equator dips to the south of the sun. The distance o-b on your diagram can be easily found by using the formula; o-b equals the radius of the drawing multiplied by the sin of angle B. The longitude of the centre of the disc is given in the Handbook by L. Diagram 2 is an example for March In the Handbook, P is minus 21.68, B is minus 7.23 and L is plus The minus sign means that the axis lies to the west of the north-south line. * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *

8 2565 ELMHURST ST. OTTAWA 14, O NT. TO: ASTRO N OTES