Star*Points for January, 2014
Jupiter in January and Some Tips for New Telescope Owners
It’s time to once again look ahead at the new year and the events we can expect in the celestial sphere. Got a new telescope for Christmas? Read on for some advice on preparing it for use that can save time and frustration.
First, a bit of old news – a final word on Comet Ison. The comet did not survive its brush near the sun on Thanksgiving Day. The comet disintegrated as it approached perihelion. There was no reemergence of the comet and no stunning tail. Had it survived, Comet Ison would pass just four degrees from Polaris, the north star, on January 7, and would have been visible all night long.
The “Old Farmer’s Almanac” appears to have got it right regarding Ison: “This Icarus may be completely wrecked before it even reaches perihelion. That is the great unknown.”
Jupiter dominates in January with opposition (opposite in direction from us as the sun) on the 5th. The king of planets rises early and remains up all night. Currently in Gemini, Jupiter forms a striking triangle with the twins’ main stars Castor and Pollux throughout the month. At midnight the trio floats high overhead. Even a small telescope using a low power eyepiece will reveal the four bright “Galilean” satellites or moons. Their names are Io, Europa, Ganymede, and Callisto.
The configuration of the moons changes almost hourly. An online application for tracking their movements is available at skyandtelescope.com, Sky & Telescope magazine’s web site. Just look for the “Jupiter’s Moons” link (registration required). Enter the observation date and time as Universal Time (UT). To compute UT simply add 5 hours to Eastern Standard Time (4 hours for daylight “savings” time). The application simulates the appearance of Jupiter and its labeled satellites in a telescope.
Here are some upcoming events for 2014 visible from our area as found in Guy Ottewell’s Astronomical Calendar.
For early risers Venus will shine prominently in the morning sky in February and March.
Two total lunar eclipses are visible -- on the night of April 14-15 and another in the early morning hours on October 8. A partial solar eclipse is visible at sunset on October 23.
Mars is best placed for telescopic viewing in April. Unfortunately, it will be lackluster due to its distance from us and low elevation in the sky.
Mercury is best place for viewing after sunset in May. Likewise, Saturn is best placed for viewing all night long in May.
An unusual highlight worth keeping an eye on occurs in October. Comet C/2013 A1 (Siding Spring) and the planet Mars will have a close encounter with a small chance of the two bodies colliding.
Now let’s turn to hardware. Is there a new telescope in your house this year, or an old unused one (that’s hopefully packed neatly away somewhere and not out collecting damaging dust and grime)? One of the biggest frustrations of novice telescope users is trying to locate even bright objects using a misaligned telescope system. A few moments of preparation could prevent discouragement and save the telescope from being banished to a closet, basement, or worse.
Often telescopes are equipped with a “finder ‘scope” – a small miniature telescope mounted onto the side and parallel to the main telescope. As the name suggests, this tiny telescope’s purpose is to help find or locate objects for viewing with the bigger telescope. But when the telescopes aren’t in alignment it becomes an almost impossible task that could have been avoided.
Most “finders” are equipped with a crosshair reticle. The goal is that when a target object is centered at the intersection of the crosshair, said object will be simultaneously visible in the field of the main telescope equipped with a low power eyepiece. If that is not the case, then your finder may be out of alignment.
Take your telescope outside during the day when you can see what you’re doing. Look around for an object at least a quarter mile away. Tips of church steeples or the tops of power poles work well. At night you can use a distant streetlight.
Insert the lowest power eyepiece into the main telescope. Locate, center and focus on the object you selected. Then lock both telescope axes. Make sure the object is still centered in the eyepiece. Repeat if necessary.
Moving to the finder scope as gently as possible without bumping the main telescope, adjust the small set screws, loosening and tightening them until the object is centered in the finder’s crosshair. Tighten down the screws.
The object should now be centered in both finder and main telescope. If not, then recenter in the main telescope and repeat the process.
Once you get good at it, this adjustment should become quick and natural, taking only seconds to complete. By that time you can probably do it quickly at night using a bright star or planet.
Here is how to use your finder during an observation. First, insert the lowest power eyepiece in your main telescope. This is true when you’re starting out for the evening or when switching from one object to another.
Unlock the lock knobs on the axes of your telescope while keeping control over the telescope with your other hand. While moving the telescope, sight through the finder until the target object can be seen in it. Center it on the crosshair and then relock the knobs on the axes.
Now, when you look in the eyepiece of your main telescope the object should be in the field of view. Adjust telescope to center the object. If you want to increase the magnification, replace the eyepiece with one that has more power.