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BT MON brightening?

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lmk
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Joined: 2010-07-23

 

I think I observed it at v=14.6 last night, but there is a very close companion which makes visual estimation difficult, and I was plagued by poor seeing. Rod Stubbings thought he saw a combined 13.8 there, but later said the variable was <14.4. I do have a positive observation on it some time ago at v=15.7

Could someone with a high resolution CCD please check this star?

Thanks!

Mike LMK

BT MON brightening?
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bdg
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Joined: 2010-07-24

I've reported 3 unfiltered CCD observations to the database this evening which show BT Mon varying from 15.14 down to 15.30 then back up to 15.16 over a two hour interval. This is at the bright end of its usual range of variation. See Fig 7 in my paper in JAAVSO Vol 40, 1, 295.

Regards,

David BDG

BT Mon brightening
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dks
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Joined: 2010-07-26

I was able to cleanly resolve BT Mon from its close companion on one of the three images I took - wind is wrecking havoc with observing tonight. On that one image I measured it at v=15.1 +/- 0.1 mag.  I'll try to get a few more images between wind guests!

Shawn (DKS)

It seems to be showing considerable variations
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lmk
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Joined: 2010-07-23

Since my v=14.6 observation on Mar 2, I observed it fainter than 15.8 on Mar 7, then up to 15.0 on Mar 10. Also, the last observation it showed short time scale fluctuations/flaring of several tenths. I don't recall seeing such wide and active variations in this star before, which is why it prompted this forum thread.

Mike LMK

AAVSO 49 Bay State Rd. Cambridge, MA 02138 aavso@aavso.org 617-354-0484