Beginners' Learning Experience

American Association of Variable Star Observers (AAVSO)
Thu, 06/14/2012 - 14:42

Recently I've made an effort to get out and do some observing of variable stars. I'm new to this kind of observing so its a fairly slow process for me as I want to make sure I'm as accurate as possible.

Last night I had planned to continue working on the 10 star tutorial. I first started looking for the variable star delta Cephei. Using Polaris I scanned eastwards and found the constellation Cepheus. I live in the city and with the sun only having set about 1 an hour ago I started to make out the constellation brightest stars. A little later I was able to see the variable star and was able to make an estimate based on the comparison stars suggested on the chart.

Next I scanned round in a southerly direction and found what I thought was the constellation Aquila and started to look for the variable star eta Aquilae. I could make out the two upright triangles back-to-back but had difficulty finding eta Aquilae. After a while and using the suggested comparison stars, scanning back and forth I was able to satisfy myself that I was looking at the right variable. However something wasn’t right, one of the stars I was comparing with seemed dimmer than it should be. After some further looking I was convinced it was just my new observing skills and made an estimate. I then proceeded to look for R Cyg. I moved over to my telescope and looked at the sky and then it dawned on me - I had been looking in the wrong area for the constellation Aquilae. I had been looking too far south and too high up in the sky. Part of my view had been obscured by buildings. Now I was standing I could Aquilae clearly with the bright star Atlair. Making the estimate now was easy and coincidently came up with the same estimate for the variable as before.

This was a learning experience for me in that you have to question thoughly when something does not add up. I wonder what stories others have that added to the learning experience?




Congratualtions on your efforts to observe variable stars and learn your way around the sky. The old saying "practice makes perfects" applies here. I have been visually observing variables since 1973. 


I am the Moderator of the Visual Observing Forum. I'd love to have you chip in on this forum. We just started it running. We can teach each other lots of things here, and have great discussions about stars and equipment.


If you want, I can give you some suggestions on some great northern  long period variables that would suite you well. What size telescope do you have? Is it a reflector or refractor? I see you are in the city, so I once I know your scope size, I can get you a list of 10 or 20 stars and you can make charts for them using the VSP chart generator.


Chris Stephan   SET

Robert Clyde Observatory

Sebring, Florida  USA

American Association of Variable Star Observers (AAVSO)
Telescope Type

Hi Chris,

I own a 10" dob. The sky conditions in my city normally reveal three of the brightest stars in the Ursa Minor constellation. Last night was unusual in that  I could just make out the other stars in the Little Dipper. They were kind of winking in/out.

I guess I should have posted my original post in the Visual Observing Forum. I did not see it initially listed.

Thanks for your help.


American Association of Variable Star Observers (AAVSO)
Identification errors and star patterns

Hi, Dave,

This kind of funny confusions may happen to anyone, even those who consider ourselves "experienced observers"!
My last observing session is a good example of that.

I observed the field of the bright mira S Car with my 7x50 binoculars and I did it at a different time that I was used to do it.
S Car is placed on a tip of a cross. It turned out that the cross was upside down since the last time I had seen it. As a result, I estimated the star on the opposite side of the cross as if it was S Car!
However, since I am very familiar with the star pattern and I usually check the comparison stars (and use more than two, making crossed estimates) magnitudes, I realized that the star at the other tip of the cross was fainter than normal! Ooooh , I have found a new variable star visually, I thought, and jumped off mi sit. I made an estimate of it and that gave me 6.7 instead of its normal V= 6.4.
To check what was going on (checking is extremely important), I got my S Car chart and it was then when I realized that I had been observing the cross upside down and my "new variable star" was actually S Car! I was disappointed but happy at the same time, because I had noticed the small difference in magnitude and that allowed me to prevent a fool mistake to go to the records.

The moral is "Always check your results if they are suspicious".

So keep observing and sharing your experiences.


doing it right



You are much shorter than I am. When you find that you are in a situation where things are upside down, try observing standing on your head. You can keep your balance better than I. 


Dave, Sebastian is my buddy and he will understand this. Don't try it yourself!!!:)


Chris Stephan

Robert Clyde Observatory

Sebring, Florida  USA

American Association of Variable Star Observers (AAVSO)
It's quite easy to

It's quite easy to misidentify. We've all done it, I think. It's especially easy to do when you have an element of 'fractality' in the field. BN Cyg for example. A very experienced observer once misidentified one of his favourite stars, V Cam, which suffers from this problem also.

Hell, I've even submitted an obs of a misidentified star (GM Cep a few years back) which was then used in a professional paper. I contacted the author last year to point the misident out, and she was very gracious!