Sunday, April 30, 2006
My 20 favorite double and multiple stars, part 1: early spring
During the last few years I “re-discovered” a group of objects that is not as badly affected by light- and air pollution as other deepsky objects: double and multiple stars. Many hundreds if not thousands can be observed from my own suburban backyard, and almost every time I point my telescope on a double or multiple star for the first time, I am in for a big surprise. There are a lot of different factors that can turn a double or multiple star into a true celestial gem. Their components often have beautiful contrasting colors or they show a huge difference in the magnitude. But also a very close couple or group of stars of the same color and/or almost equal magnitude can look simply stunning. There is no way to catch the telescopic views of double and multiple stars on a photograph, without destroying the aesthetic beauty of these truly sparkling stellar gems. On photographs stars turn into more or less disk-shaped blurry blobs of light. Gone are the sparkling colors, the point-like star-images and the stunning differences in magnitudes. So no matter where you live, whether in the city, somewhere in the suburbs or in a rural area, go out and observe them with your own eyes, using binoculars or a telescope. Only then you will “see” the real beauty that this often neglected group of deepsky objects has to offer.
Monday, March 27, 2006
Double rainbow
Just after dinner we saw a double rainbow right above the street where we live. I rushed outside to find the pot of gold at the end of the rainbow, but once I was outdoors, I decided that the view was too beautiful to be ignored. I quickly grabbed my camera and shot a few images and after that, I simply enjoyed the view. The new telescope will have to wait a littlle longer (sigh).
Click to enlarge!
Friday, March 24, 2006
Lunar fact sheet
In the last few weeks I collected some basic lunar data from different online resources and books. I allways find it handy to have this kind of related data grouped together. Click on the image below to enlarge. Of course you are free to download and print the fact sheet. Just click on this link to download the PDF.
Click to enlarge
Thursday, March 23, 2006
Searching this blog, posting comments and register for my newsletter
I just had my blog updated by Mel from "emtwo webstudios". There were a few minor (security) problems with the blog, and I'm glad that they everything is working fine again. Maybe this is the good time to tell you how to search my blog and how to post comments, because both features have been updated. At the end of the article you will find how to register for my newsletter.Searching items in Clear Skies On Demand
There are three ways to search certain items in my blog. All three options can be found in the sidebar of the blog: Categories, Archives and Search. I will try to explain the differences between the different search methods.
Monday, March 13, 2006
Observing the Moon for beginners
Beginning backyard-astronomers often ask me “what do I need to start observing the Moon”. Basically you only need two things to start off with lunar observing: a small telescope (or binoculars) and a map of the Moon. You also should know a few other things: when to observe the Moon and what to observe (as a beginner). In this article I will try to answer these questions. In the near future I will write an article for those wo are past the beginning stage, the "intermediate" observer. This article however, is meant for the beginning lunar observer.
Friday, March 03, 2006
Zeiss Diascope and Coolpix 4500 for Birding and Lunar Imaging
During the last few months I have frequently been asked about the new setup that I use for birding and for imaging the Moon: what setup do you use for birding and for imaging the Moon, and why do you image the Moon with the Zeiss Diascope anyway. Why not use the TAL 200K or the TAL 100RS?
I will start with answering the last question first, why do you image the Moon with the Zeiss 85mm, why not use you’re 8-inch TAL Klevtzov or 4-inch TAL reflector. In the second part of the article I will tell you more about the setup I use for both imaging the Moon and for birding.
Monday, February 20, 2006
Lunar phases
Why do you see different portions of the Moon lit by the sun
The Moon has no light source of its own. It "shines" because it reflects sunlight. At any given moment, half of the surface is lit while the other half is dark. On the Moon there is night an day, just as on Earth. But what causes the changing appearance of the Moon, what causes the lunar phases?
Monday, February 13, 2006
Copernicus and Montes Riphaeus
On Monday January 9, between 16.00 hrs UT an 18.00 hrs UT, I observed a nine-day-old Moon and shot a few images of different parts of the lunar landscape. I used the TAL 200K combined with various eyepieces to observe the Moon visually. The eyepieces ranged from a 32m Televue Plossl to a 5mm Vixen Lanthanum. For me, the most interesting features imaged were Clavius (previously published in this blog), Copernicus and Montes Riphaeus, and finally the Plato area (will be published in the near future). I used the Nikon coolpix 4500 and a 20mm Vixen Lanthanum eyepiece combined with a Baader IR/UV cut filter for the overview image of the Copernicus-Riphaeus area (images 2 and 3).
