[vsnet-chat 4606] DY Crucis , methods, mu Centauri and Be stars

["Sebastian Otero" <varsao@sinectis.com.ar>]

Hi, all:
          I was out for a week in a LIADA star party in Villa Carlos Paz,
Argentina. I am happy to read that the Name List # 76 is already out.
         DY Crucis (former NSV 19481) is a very difficult star to observe
and I agree with Brian that colour problems may account for the different
amplitudes reported. My observations show a range of 8.3 - 9.9 and it is
very difficult to find a period from these data. I think it is an actual "L"
star. For instance it is around 8.5 (maximum) for a hundred days now !!!
          I think it is important to mention that my method for these red
stars are totally the opposite as stated everywhere:
I stare at them until I can get a full impression of the brightness of the
very punctual source. I have found that Purkinje effect needs to be avoided
by using quick glances when speaking of naked eye stars. When we are at the
eyepiece, the sky is darker than that observed with the naked eye because of
the magnification so the problem is minimized and since the brighter the
star the better the colors are perceived, when we look at faint red stars it
is needed to look at them carefully if we actually want to even detect them.
         The chart I have prepared for LIADA with this star and other
variable we discussed more than a year ago with Brian (the possible T Tauri
star CPD -58 4492) can be obtained from my website but there is some kind of
problem going on right now so I'll send it to vsnet-image.
There are also a lot of bright variables' charts in:
http://ar.geocities.com/varsao/cartas_de_variables.htm
Comparison stars' magnitudes go to 2 decimal places since there's no point
in rounding off photoelectric values. Numbers between brackets are B-V
indexes that are the main tool for my method to get stuck to V magnitudes
while making visual estimates.

          I was also happy to learn that the mu Centauri outburst I detected
made its way to the IAU. The outburst faded rapidly in light but it was the
brightest state I've seen for mu Centauri since I started observing it in
1997.
         I will answer all mails about Be stars (my main interest right now)
in the next days.
I just want to mention that delta Scorpii is rising slowly again as
predicted and that lambda Pavonis got bright (4.1) some days ago. I wasn't
able to report it at that time but I'm sending all my star party
observations to vsnet-obs.

Cheers,
Sebastian.




---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://vsnet.grisoft.com).
Version: 6.0.262 / Virus Database: 132 - Release Date: 12/06/01

VSNET Home Page

Return to Daisaku Nogami

---

vsnet-adm@kusastro.kyoto-u.ac.jp