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Campaigns & Solar conjunctions

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lmk's picture
Campaigns & Solar conjunctions

I notice again the BF Cyg campaign right now, and the upcoming AN 511 first segment campaign are difficult or impossible for us earth-bound observers to help with. The objects are too close to the Sun. I recall several similar situations in other campaigns in recent times.

I am just wondering if this "bad timing" is purely coincidental, or is there something about the scheduling process of space-based telescopes, that makes them prone to objects near solar conjunction? Maybe there is something AAVSO can do pro-actively to assist PI's in their selection of targets for these campaigns to avoid the Sun?

Just asking.

Mike LMK


Matthew Templeton
Spitzer and the Sun

Hello Mike,

Spitzer has both a minimum and a maximum solar angle (around 80 and 105 degrees, I believe).  For that reason, each point in the sky is visible twice a year.  Spitzer is in Solar rather than Earth orbit, so relative to Spitzer these fields aren't as close to the Sun as they are for Earth.

We talked with the PI, and they know its a tough observation right now.  Six months from now the stars will be more favorably placed, and we'll make another announcement then.


Matthew Templeton
And BF Cyg...

Regarding BF Cyg, it isn't too close to the Sun.  George Wallerstein is getting ground-based spectra himself right now, and if you look at the AAVSO light curve, there are no prominent seasonal gaps.  Inconvenient to some, maybe, but not invisible.

Further, please note this request came about because BF Cyg is doing something interesting right now.  It was not a "planned campaign".

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