Urban Binocular Variable Star List

A few months ago, I decided to create a list of variable stars observable with my binoculars from city. I started with downloading data for variable stars reaching at least 7.5 magnitude brightness from VSX variable star catalog as explained here. After downloading the data, i filtered out supernovae and novae except recurrent novae. Then removed variable stars with magnitude change less than 0.4. Afterwards i excluded all stars without "V" or photographic magnitude data. Finally i removed suspected variables.
The resulting list can be found here.
The list contains data for 638 variable stars and i hope it helps you to find variable stars to observe.

Baader Astro Solar Filter

2 weeks ago, I ordered Baader Astro Solar Film from Baader Planetarium. My main purpose was to observe Venus transit on 5-6th June 2012. It arrived as a A4 size sheet of  solar filter placed in a hard envelope. I built the filter as explained here but the resulting filter looked rudimentary because of my lack of hand skill. Next morning i could not wait to take trial shots with the filter and found out that although the filter does not look promising, the image quality was nice. For example, following picture was taken on 11th February 2012 morning and you can see 2 close sunspot sharing same sunspot number.

Sony DSC-H1, fl:432mm (35mm equivalent), f/5.6, 1/500s, ISO 64, ND5 Solar filter

The sunspots seen on the picture are smaller than Venus' size during transit so it seems that i can take Venus transit shots with this filter if weather permits. This year Sun is quite active so i wish i can take better sunspot shots this year.

Go Voyager 1

According to last  Voyager Mission Status Report,  a heater on Voyager 1 spacecraft was turned off in order to reduce power consumption of the spacecraft. The good news is, the aim of reducing power consumption is to extend the mission to 2025.

Special Astronomical Events in 2012

I checked NASA Space Calendar for important astronomical event of 2012 and marked them on my calendar. This year's top event is Transit of Venus on 5th-6th June. Next transit of Venus is 105 years later so this will be our last opportunity to see that event. Sky and Telescope has an article about the event in January 2012 issue and there is an online article on their website.
There will be 2 solar and 2 lunar eclipses in 2012.
On 20th May, there will be an annular eclipse visible from China, Japan, Pasific and Western United States. For details check here.
On 4th June, there will be a partial lunar eclipse visible from Pasific Ocean, most of Americas and Eastern Asia. For details check here.
On 13th November, there will be a total solar eclipse visible from Austraila and Southern Pasific. For details check here.
On 28th November, there will be a partial lunar eclipse visible from Asia, Australia, Europe, Eastern Africa and North America. For details check here.
2012 is a Mars opposition year, this opposition will be on 3rd March.
There will be a close opposition of asteroid Eros on 7th February. It will reach 8.6 magnitude in those days and it will not be any closer until 2056. For details check here.

M101 and Supernova 2011fe

Even after a long delay, i am not writing about what i promised. I had to stop blogging for a few months and i believe that i will orgsnize what i have and continue with variable star observing.
During my absence, one of the most interesting astronomical events was the supernova in M101 galaxy, namely Supernova 2011fe. According to AAVSO, it is "The brightest supernova in the last 20 years!" reaching 9.5 magnitude. Because M101 is a very popular photographic and visual target, the supernova has been detected in very early stages of explosion and examined very thoroughly.
It is very difficult to see M101 galaxy in a city due to its very low surface brightness but the supernova (because of being a point source) was much easier to see.
I observed the supernova when it was near 10.0 magnitude and it was fairly easy to see, actually more difficult thing was to starhop to the location of the object. Of course the galaxy was not there even though its total brightness was about 3 magnitudes more.

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.