Variable Star Observing In City: Introduction

Variable star observing is known to be one of the most accessible ways of contributing to science for an amateur astronomer. When I first learnt variable star observing, it seemed attractive but I scared to “ruin” collected scientific data by my “incorrect” brightness estimates. Therefore, I decided not to do variable star observing and concentrated only on leisure activities like deep sky or planetary observation. In 2009, I encountered an article in Sky and Telescope magazine about Epsilon Auriage and then heard 10 star program. They changed my opinion about variable star observing.

10 star program is a variable star observation program about 10 bright variable stars. They are all naked eye stars but in city most of them may require binoculars especially at minimum brightness. The tutorial is aimed to train the novice variable star observers through 10 easy to find and observe variable stars with particular emphasis on Epsilon Aurigae. It briefly explains how to estimate brightness of stars and how to use variable star charts.

If 10 stars do not seem enough to you (like me), you can continue with AAVSO Visual Observing Manual and vast information in AAVSO website. “Observers” section in AAVSO website provides links to the list of stars easy to observe, 10 star tutorial, WebObs (online observation entry page), VSP (chart generation tool), recent observations of stars and observing sections’ pages. After making your observations, you need to record them. The easiest way is using WebObs through its basic interface; however, before that you need to get observer initials from “Observers” page. Observer initial is the unique code of an observer and your observations are tagged with your initials. After getting your initials, username and password, you are ready to log your observation.
In the next post, we will explore variable star observing in city with binoculars.

13mm Nagler Type 6: First Light

In his book The Urban Astronomer's Guide: A Walking Tour of the Cosmos for City Sky Watchers (Patrick Moore's Practical Astronomy Series), Rod Mollise says that wide field eyepieces will help in deep sky observing by providing enough field of view while keeping magnification high. It is well known that high magnification darkens background so contrast between object and the light polluted background improves thus the observer can see the object easier.
As a stargazer observing under heavy light pollution, I followed his advice and decided to get a 82-degree eyepiece. I made an extensive research on optical performance and availability of the alternatives and decided to get 13mm Nagler Type 6. 13mm Nagler gives 94x magnification (a very useful magnification) on my 8 inch dobsonian with apparent field of view of 52 arcminutes. I bought it from amazon.com at about 220$.
The eyepiece is larger than my 26mm Meade Series 4000 Super Plossl but smaller than 32mm Celestron Plossl. Physical quality was very good and the dust caps fit securely. The first look was very pleasant though not stunning (i expected more immerse effect)  and the large field of view was really obvious. I compared the view with 26mm Plossl and 2x Barlow and of course Nagler's image quality was better. But this comparison showed me a shortcoming of Nagler compared to Plossl: Lack of eyecups. I find it more difficult to use Nagler after placing my eyes on the eyecups of the Plossl. The Nagler is still pleasant to use though and when i switched back to Plossl from Nagler, i felt as if i was looking through a narrow pipe. I have not looked to a planet or the Moon with my new eyepiece and i am looking forward to observe them and report Nagler's performance. I am glad that i got this eyepiece and hope to enjoy it for many years.