SKY WATCH January 1996

by Harry Adams


So that shiny new telescope is still sitting under the tree just waiting for first light. Well, here are some hints to make using it a little more rewarding if you are new to amateur astronomy.

First, put everything together indoors and familiarize yourself with pointing, focusing and changing eyepieces. These are not the kind of things you want to be doing for the first time out in the dark on a cold January night. Be sure to determine how tightly the thumb screws need to be set in order to hold the eyepieces in place.

Next, do a preliminary alignment of the finder telescope. Use a low power eyepiece and point the telescope out a window. Find the most distant object you can with the main telescope and then lock the telescope in position. Now use the adjustment screws on the finder to bring that same distant object in line with the crosshairs. Take your time. A well aligned finder is your best friend.

Now is a good time to check for field reversal. Look at a sign through the telescope. It will probably be upside down but is it mirror imaged as well? If it is then you will have to mentally flip your star charts or view them with a mirror when trying to identify fields through the eyepiece.

Low temperatures will stiffen any grease in the focuser, so check if there is a screw or two you can adjust to loosen the mechanism a bit. If there is an adjustment experiment with it and put the screwdriver in you coat pocket for later. When using the telescope, leave the plastic lens covers indoors since they shrink much faster than the metal parts they mate to and will be impossible to put on if cold.

Arrange your eyepieces in a plastic food storage box with a tight fitting lid. This air-tight container prevents moisture from condensing on the cold eyepieces when you take them back indoors. Put a thin piece of foam rubber in the bottom to cushion them and to keep them from rolling around when the lid is on. If you want you could use a thicker piece of foam and cut holes in it to fit each eyepiece.

Cover the telescope with a large plastic bag drawn tight around the top of the tripod and store it outside in an unheated garage or shed. It has to be at ambient temperature before you can use it so make sure the bag is secure to keep out moisture and insects.

The night has finally arrived. The sky is clear. The scope is ready. What do you look at? The best first target is, without question, the Moon. It has lots of detail, its bright and its easy to find. Be sure to check out the alignment of your finder here, before you go on to more difficult objects. Try higher power eyepieces out and see if the alignment holds up. Since the moon is half a degree in diameter, estimate the angular diameter of your telescope's field of view for each eyepiece. This is useful to know when using starcharts to locate objects.

Next try to find Saturn. The rings are almost edge on and may be difficult to see but the planet will show a definite disk at 40 power. Notice that the image leaves the field more rapidly when you try higher magnifications. It is important to have objects well centred before switching to higher magnification eyepieces and to do so without bumping the telescope. Planets may produce images which have red and blue fringes on the top and bottom when viewed near the horizon. This is an atmospheric effect and not a fault in the telescope.

Now for a more difficult target. Locate the star Almach (Gamma) in Andromeda. Focus for the smallest, sharpest image. Almach is a beautiful double star with the brighter component orangish and the fainter one greenish. The separation is only 10 seconds of arc, so use higher magnifications until you get a good split.

Sweep through the winter Milky Way and pick out the open clusters M34, M35, M36, M37 and M38 and finally, take a look at M42, the Orion Nebula. See if you can see the four stars of the Trapezium multiple star system at the nebula's heart. Notice the colours in the gaseous tendrils and the dark dust lanes.

Put the lens covers and dust cover back on and return the scope to the shed for the next session under the stars. Seal the eyepiece box and bring it in the house but don't open it for a few hours until the lenses have warmed. Warm your toes by the fire and finish writing up your observations in your logbook. Remember, if you don't write it down, you haven't really observed it.

January's star chart is for 21h EST. The chart shows the sky for the middle of the month, looking to the South, from the Horizon (curved line near the bottom) to the Zenith (the point directly overhead, labeled Z on the chart). The directions southeast (SE), south (S) and southwest (SW) are shown on the Horizon line. Brighter stars are represented by larger dots, fainter stars by smaller dots. When magnitudes are given, more negative values indicate brighter objects. All times are given in Eastern Standard Time this month.

The Sun rises at 7:48h on the 15th and at 7:35h on the 30th. The trend to earlier risings begins in early January and continues until the middle of June. Sunset occurs at 16:50h on the 15th and at 17:11h on the 30th. Later sunsets start in early December and continue until late June.

Mercury is best seen on the evening of January 2 when it stands 12 degrees above the southwest horizon at sunset and shines at magnitude 0.5. By the 15th it is only 6 degrees high and has faded to magnitude 3.2. Setting at 17:32h, it is a difficult target. On the 18th it is between the Earth and the Sun and reappears in the morning sky after this date. On the 30th look for it in the morning sky at magnitude 0.6 and standing 10 degrees above the southeast horizon.

Venus hangs like a diamond against the blue velvet of evening twilight this month. At magnitude -4.0 it is the brightest of all planets. It can be seen all month in the southwest at sunset, standing about 25 to 30 degrees above the horizon.

Mars is gradually slipping behind the Sun as Earth races ahead of it. The red planet shines at magnitude 1.1 this month and stands only 6 degrees above the southwest horizon at sunset, making it very difficult to see.

Jupiter is a morning planet this month and shines at magnitude -1.8. It rises at 6:26h on the 15th and by sunrise has climbed 10 degrees above the southeast horizon. On the 30th it will rise at 5:41h and stands 13 degrees high by sunrise.

Saturn shines at magnitude 1.2 this month. On the 15th it can be seen 37 degrees above the south-southwest horizon at sunset and sets four hours later. On the 30th it stands 32 degrees high in the southwest and sets at 20:47h.

Moon FM - 5th, LQ - 13th, NM - 20th, Q - 27th

The Quadrantid Meteor Shower reaches maximum on the 4th this month. The Full Moon on the next day makes this an unfavourable apparition. A few meteors may be visible so watch if you're out.

Back issues of Sky Watch are now available on the Deep River Astronomy Club's world wide web page at http://intranet.on.ca/~rbirchal/draco.html .

References: Burnham's Celestial Handbook, R.Burnham, Jr., General Publishing Co., Toronto. The Observer's Handbook of The Royal Astronomical Society of Canada, edited by Roy L. Bishop, University of Toronto Press Incorporated. Star chart produced using Guide 4.0 software by Project Pluto, with permission.


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