American Association of Variable Star Observers (AAVSO)
Thu, 06/14/2012 - 18:22

I used VSP and got chart 5994rxd, but the brightest comp star is 35 (gam Cet). How do I get a plot with comp stars up to mag 2.0?

I tried varying plot scale and mag limit in VSP, but sometimes get plots for VZ Cet (e.g. chart 7791EE), even after doing a reset.

American Association of Variable Star Observers (AAVSO)

Naked eye variables like this one may require special charts because some comparison stars may be too far away.
If you need brighter stars to estimate Mira, you can use bet Cet (V= 2.04); alp Phe (V= 2.39); alp Cet (V= 2.53) and gam Eri (V= 2.95). The last two are slightly variable (less than 0.1 mag.) but it's all that we have and they have similar color.
I may suffer from a Southern bias because I live 35ºS. If you are in the Northern hemisphere, the stars is Aries might be of help.

On my website I have a lot of charts for bright naked eye and binocular variables that you may find useful.

This one is for the brightest state of Mira.




Hi Spence,


I use Alpha Cet at 2.5, Gamma at 3.5. delta at 4.1. Alpha Ari is 2.0, but there may be a more updated mag on Alpha Ari.


Chris Stephan  SET

Robert Clyde Observatory

Sebring, Florida