[vsnet-unknown 120] Re: [vsnet-campaign-unknown 135] Re: MisV1147 Spectra...

["Mike Simonsen" <mikesimonsen@mindspring.com>]

Hi Stan,

The Cep in the text file name just denotes the constellation it resides in,
not the type or suspected type.
(All the files on my website are listed alphanumerically by constellation)
http://joevp.20m.com/charts/

The C notated in the range does stand for unfiltered CCD, but it should be
changed to reflect out most current measures in V. I'll add it to the pile
of 'things to do yesterday' :-)

Best guess at the moment is this a reddened A or B type star. Fades are
likely obscuration events.

Without access to spectroscopy in the faint state we asked Henden to measure
it in UBVRI during a recent fade, just to get some idea of what is
happening. It gets redder as it fades.

  HJD                 V     B-V    U-B    V-R    R-I
52577.6706 14.876  0.933  0.044  0.706  0.906

data from first night:
52288.6100 13.365  0.814  0.087  0.558  0.628

This has proved to be an interesting target if for no other reason than it
is unpredictable and changes occur on relatively short time scales.

Very few of the MISAO project stars have substantial light curves. Lots of
new territory to explore there.
http://vsnet.aerith.net/misao/

Mike




 ----- Original Message -----


Hi Doug,

No, I'm a pep man so I merely look at the positions in the colour/colour
diagram (B-V/U-B). It's hard to get any single star with the colours you
described. Some emission would help, but this is not common for F and G
stars. Does anyone publish light curves of all these Mis objects? I see that
it's close to the galactic equator so probably has some reddening. Rather
like the stars near V4742 Sgr - I was impressed the way a dark region
crossed this field to the SW of the nova and blotted out about half the
stars there.

Since writing this I've received a note from Mike Simonsen and the Henden
sequence. Not too much sign of reddening there. But I note that the star is
labelled Cep with an amplitude of 12.3-13.8C. I'm unfamiliar with the C but
presume that it denotes unfiltered CCD. Does Cep mean Cepheid? No period was
quoted. The range seems excessively large for a Cepheid, especially through
what amounts to a red filter, unless it's a very long period object. The
presence of a companion would diminish the amplitude quite substantially,
although perhaps not much in R if the companion was blue. It all looks a bit
strange - perhaps I'm misreading the Cep and the range? The colours you've
quoted seem even more curious. Was there an error with the U-b, which seems
out of step with the others? A shame the star is not visible from 35S!

Regards,
Stan

VSNET Home Page

Return to Daisaku Nogami

---

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