Archive for the ‘Buying a Telescope’ Category

01/02/2015 – Ephemeris – Telescope Clinic tonight in Traverse City

January 2, 2015 Comments off

Ephemeris for Friday, January 2nd.  The sun will rise at 8:20, the latest sunrise of the year.  It’ll be up for 8 hours and 53 minutes, setting at 5:13.   The moon, 2 days before full, will set at 6:38 tomorrow morning.

Did you or someone in your family get a telescope for Christmas, or have one in a closet or attic because you don’t know how to put it together or operate?  Or maybe you are trying to figure out which one to buy.  Well, tonight’s your night.  The Grand Traverse Astronomical Society will host a telescope clinic at Northwestern Michigan College’s Rogers Observatory on Birmley Road, south of Traverse City starting at 8 p.m.  Telescope experts from the society will help you set up your telescope and give you observing tips.  So bring ’em if you’ve got ’em.  If it’s clear, at 9 p.m., there will be a star party to try out your telescope, or try them out on the lights of Traverse City.  Can’t make it?  We can help you after any meeting.

Times are for the Traverse City/Interlochen area of Michigan.  They may be different for your location.


Remember the Quadrantid meteor shower tomorrow evening and into Sunday morning:

The moon will interfere with the meteor shower, so only the brightest will be visible.  The radiant will rise from the northeast.  The radiant will be nearly overhead at the start of twilight.  On a dark night up to 120 meteors per hour may be seen according to the International Meteor Organization.

Quadrantid meteor shower radiant at 1:30 a.m.


The Earth will reach perihelion Sunday.
This is the closest the Earth gets to the Sun in its orbit this year.  The Sun will be 91,402,000 miles or 147,096,000 kilometers away at around 1 a.m. January 4th, 2015 EST or 6 hr UT January 5th 2015.  It makes winter the shortest season because the Earth is moving its fastest during perihelion.  It’s only by a few days.  And in northern Michigan where it seems that winter overlaps half of fall and spring besides, that few days difference is buried under snow.

11/19/10 – Ephemeris – Where to look for telescopes

November 19, 2010 Comments off

Ephemeris for Friday, November 19th.*  The sun will rise at 7:44.  It’ll be up for 9 hours and 26 minutes, setting at 5:11.   The moon, 2 days before full, will set at 6:45 tomorrow morning.

We’ve been talking about telescopes this week.  So, where can you buy a good telescope?  A camera store or nature store may have someone knowledgeable about telescopes.  The Internet is also useful in learning about telescopes and directing you to reputable dealer.  Astronomy dot com is one site where you can learn about telescopes.  Astronomy and Sky and Telescope magazines, available at book stores, have information and ads for telescopes and accessories.  Generally, good telescopes may not be in-stock locally and have to be ordered.  What do I have?  Several binoculars, an eleven inch reflector on a Dobsonian mount, and an eight inch Schmidt Cassegrainian reflector which has Go-To tracking.  Remember telescopes are rated by their diameters.

* Times, as always are for the Traverse City/Interlochen area of Michigan.

11/18/10 – Ephemeris – Binoculars an ideal first telescope

November 18, 2010 Comments off

November 18th.*  The sun will rise at 7:43.  It’ll be up for 9 hours and 28 minutes, setting at 5:11.   The moon, 3 days before full, will set at 5:39 tomorrow morning.

There’s a bewildering choice of telescopes, and tomorrow I’ll show you where to go to find that choice.  But for a first telescope, there’s nothing better than a pair of binoculars.  Binoculars beside quality, have two numbers that describe its capability.  They are like 7X35, 8X50, 10X50, and so on.  The X is pronounced “by”.  The first number is magnification, which is usually fixed in binoculars.  The second is the diameter of the front or objective lens in millimeters.  The best binoculars for astronomy are those where the second number divided the first comes out to be 5 to 7.  A 10 by 50 binocular gives an answer of 5.  All real binoculars use prisms to make the image upright.  Telescopes give upside down images.

* Times, as always are for the Traverse City/Interlochen area of Michigan.

11/17/10 – Ephemeris – The bright planets for this week

November 17, 2010 Comments off

Wednesday, November 17th.*  The sun will rise at 7:41.  It’ll be up for 9 hours and 31 minutes, setting at 5:12.   The moon, half way from first quarter to full, will set at 4:35 tomorrow morning.

Lets take a look at the bright planets for this week. Mars is very low and lost in the evening twilight.  The planet Jupiter is up at sunset appearing in the southern sky in the early evening.  It will move due south at 8:33 p.m..  It is the brightest starlight object in the sky.  It’s located in Pisces this year and will set at 2:19 a.m.  The ringed planet Saturn will rise at 3:56 a.m. in the east southeast.  It’s located in the constellation Virgo this year.  It’s rings are opening nicely for telescopic observers.  Venus is in the morning sky and will rise at 5:18 a.m. in the east southeast but may be hard to spot in the twilight.  Mercury is also too close to the sun to be seen.  It’s near where Mars is this year, in the evening sky.

* Times, as always are for the Traverse City/Interlochen area of Michigan.

11/16/10 – Ephemeris – Important telescope properties

November 16, 2010 Comments off

Tuesday, November 16th.*  The sun will rise at 7:40.  It’ll be up for 9 hours and 33 minutes, setting at 5:13.   The moon, 3 days past first quarter, will set at 3:32 tomorrow morning.

This week we’re looking at selecting a telescope for a gift.  All things being equal, telescopes have two properties.  They are light gathering power and resolving power.  They are both related to the diameter of the primary mirror or lens.  Light gathering power is as it says the ability to see  faint objects.  Resolving power is the ability to see fine detail in an image so that more magnification can be used without producing fuzzy image.  This is a limitation that’s caused by the wave nature of light itself.  Also of equal importance with the optics is the telescope mount.  If it isn’t solid and smooth moving it makes the telescope useless.  Magnification in telescopes can be changed by using different eyepieces, so it is not an actual property of the telescope itself.

* Times, as always are for the Traverse City/Interlochen area of Michigan.

11/15/10 – Ephemeris – What kinds of telescopes are there?

November 15, 2010 1 comment

Monday, November 15th.*  The sun will rise at 7:39.  It’ll be up for 9 hours and 35 minutes, setting at 5:14.   The moon, 2 days past first quarter, will set at 2:31 tomorrow morning.

This is the time of year that telescopes are being looked at as gifts for that budding astronomer. This week we’ll take a look at what’s important in selecting a telescope.   There are two types of telescopes, ones that use lenses to form the image, called refractors and ones that use mirrors called reflectors.  There are several kinds of reflector telescopes but reflectors tend to be wider than refractors and have a greater ability to produce bright images.  However refractors are everyone’s first idea of what a telescope looks like, but in reality most amateur astronomers use reflectors and all professional telescopes made in the last century are reflectors.  Tomorrow we’ll look at what’s important, and it isn’t magnification.

* Times, as always are for the Traverse City/Interlochen area of Michigan.