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Observing variables

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11 replies to this topic

#1 kappa-draconis

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Posted 24 April 2019 - 10:19 PM

So I've been meaning to do a variable star observation for a while. I don't have fancy equipment: just binoculars that I hand-hold for now. Every time I find a star I get excited about, it turns out that the comparison stars available won't permit a good observation (to estimate an apparent magnitude). Can anyone provide any guidance on stars that would make good targets this time of year, considering my setup? I'd appreciate any help you can provide. 


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#2 kappa-draconis

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Posted 25 April 2019 - 12:53 PM

I hope there are at least a few! cool.gif



#3 zleonis

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Posted 25 April 2019 - 02:10 PM

I'm not a variable star observer by any stretch, but you might check out AAVSO's Binocular Program. This time of year, it looks like X Crc, R Leo, Z UMa, SS Vir, V CVn, R Boo, R CrB, and AH Dra could be reasonable options with decently wide variation that could be fun to track. AASVO will help you generate star plots with comparable magnitudes listed. 


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#4 kappa-draconis

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Posted 25 April 2019 - 09:02 PM

Hi zleonis, thanks for taking the time to answer. 



#5 kksmith

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Posted 26 April 2019 - 05:14 AM

I was a AAVSO member as a teenager back in the 70's. For the longest time just with a pair of old bino's. Then I moved up in the world with a 3" reflector LoL. I picked stars based on the availability of comparison stars. At first I thought the idea of judging magnitude daunting. But when I received the plotted results from others observing the same stars - my estimates matched theirs. It was a nice confirmation that my Mark 8 eyeball was well calibrated. I enjoyed the idea of getting stars to observe and plot out magnitude changes.

 

Enjoy a fun night past time.

 

Ken



#6 petmic

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Posted 26 April 2019 - 05:23 AM

 Can anyone provide any guidance on stars that would make good targets this time of year, considering my setup? I'd appreciate any help you can provide. 

I am too keen to start with variables. I have already tried few times but found the learning curve very steep. I do not understand how one can estimate the brightness when the designated comparison stars are well outside of the FOV when the variable is centered in the EP. I would appreciate if someone could recommend few variables that can be a good starting point for an absolute beginner. I didn't find the AAVSO guide very helpful. 


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#7 kappa-draconis

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Posted 26 April 2019 - 06:53 AM

Peter, I could not agree with you more. There should just be a plugin in Stellarium that can help you do an observation. 



#8 zleonis

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Posted 26 April 2019 - 11:53 AM

I am too keen to start with variables. I have already tried few times but found the learning curve very steep. I do not understand how one can estimate the brightness when the designated comparison stars are well outside of the FOV when the variable is centered in the EP. I would appreciate if someone could recommend few variables that can be a good starting point for an absolute beginner. I didn't find the AAVSO guide very helpful.


Not that it necessarily solves the problem of there being few comparison stars, but the aavso plotter does allow you to specify the field of view of the chart (in arc minutes) and the limiting magnitude of stars displayed. What would be terrific is if sky Safari would let you toggle star magnitudes (like you can with star names or double star positions/separations).
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#9 kksmith

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Posted 26 April 2019 - 03:54 PM

What I did was look at the magnitude range of the variable in question and then find comparison stars in that range to bracket the V star's magnitude. Finding comparison stars that are in the FoV of the variable via a telescope is rare I found. That's why I liked doing it with bino's - easy to jump between stars. But it can be done with a telescope. To me that was part of the challenge - moving the scope from one star to the next,  back, and estimating magnitude.  I found it part of the learning curve. And after 40 years of not doing it - a perishable skill. And personably - I think it needs to be a visual skill and not a software interface skill. I learned my way around the night sky, as well as individual stars this way. But to each his own.

 

Ken


Edited by kksmith, 26 April 2019 - 03:59 PM.

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#10 tchandler

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Posted 27 April 2019 - 08:30 AM

I've been enjoying Y CnV this spring. It's a semi-regular variable (carbon star) ranging from magnitude 4.5 to 6.3. There is a 6.3 mag star (HIP 62172) located just over a degree to the south. Chara (Beta CnV) is mag. 4.2 and not too far away. Burnham's Celestial Handbook has a short write up too - it's an older write up but still of value. It seems to be near it's maximum now and its normally vivid red colouration appears faded. It has a period of about 160-180 days.

 

It's a beautiful star. 



#11 S.Boerner

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Posted 28 April 2019 - 11:15 AM

While kappa-draconis may know of this already others may not.  The AAVSO has a number of manuals for variable star observing including visual, DSLR, CCD, and exoplanets.    Looking at the manuals is a great way of getting started.  They can be found at https://www.aavso.or...serving-manuals

 

I'll add that the AAVSO's Variable Star Plotter not only can be customized for a field of view up to 20 degrees it also can display a special chart suitable for binocular observing.    A URL to the VSP page is https://www.aavso.org/apps/vsp/

 

WARNING!!!!!   variable star observing can become addictive!!!!!lol.gif


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#12 DHEB

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Posted 04 May 2019 - 10:42 AM

So I've been meaning to do a variable star observation for a while. I don't have fancy equipment: just binoculars that I hand-hold for now. Every time I find a star I get excited about, it turns out that the comparison stars available won't permit a good observation (to estimate an apparent magnitude). Can anyone provide any guidance on stars that would make good targets this time of year, considering my setup? I'd appreciate any help you can provide. 

You already got good answers, I have little else to add. The AAVSO site is full of information and useful tools (VSP, VSX, LCG, etc), it is worth exploring and reading. Also, go check the "Observational astrophysics" forum, here on CN. There is where variable star observers usually flock here.

 

Perhaps, you may also be interested in these two posts I wrote a while ago:

Towards a variable star observing program: 1. general considerations

Towards a variable star observing program: 2. choosing and selecting stars


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