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1SWASP J162117.36+441254.2 Observing Campaign

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weo's picture
1SWASP J162117.36+441254.2 Observing Campaign

AAVSO Alert Notice 569 announces an observing campaign on the cataclysmic variable 1SWASP J162117.36+441254.2 in support of HST observations. Please see the notice for details and observing instructions.

Many thanks, and good observing,

Elizabeth Waagen, AAVSO HQ

weo's picture
Thread URL in email Alert Notice 569 incorrect

In the email version of Alert Notice 569 on 1SWASP J162117.36+441254.2, the URL for the forum thread is wrong. However, in the online version of the Alert Notice, the URL is correct. My apologies for the error!

Good observing,


HST observation date now confimed

Thank you so much to all the observers who have contributed to this campaign so far. Your observations are very much appreciated! So far the target seems to be behaving itself, showing only its normal orbital brightness variations and eclipses. Great news.

Just to let you know, the HST observations have now been scheduled. 1SWASP J162117.36+441254.2 will be observed between 02 Mar 2017 22:08 and 03 Mar 2017 02:10 UT.

I need to confirm that the target is still in quiescence ~24 hr before this time, so any observations (even single snapshots) on 28 Feb - 1 Mar will be most helpful.

During the HST observation window the target will be quite low in the sky from most of your locations, but if you can observe it, time series observations during this window would be very welcome. It will help us to know exactly how bright the target is during the time of the HST observations, which will help us to separate the contributions from the white dwarf and the donor star.

Wishing you all clear skies!



Big thanks!

A big, big thank you to everyone who contributed to the monitoring of this target. I'm happy to report that the HST observations completed successfully last night and we now have a lovely UV spectrum of 1SWASP J162117.36+441254.2. I'll get stuck into the analysis and work out what it tells us! I'm happy to keep you updated if interested.

While further observations are always welcome, this completes the campaign on 1SWASP J162117.36+441254.2.


jfgout's picture
Good news!

Thanks for the update. Good to see that the observations completed successfully. I have a quick question reagrding the risk of damage to the HST. Is it that the outbursts go with large bursts in UV light? It seems hard to imagine how an increase from mag 15 to mag 13 could damage the sensors on the HST. Thanks in advance for the explanations :)

Looking forward to seeing the results.


pablotwa's picture
Just submitted mine.

I just submitted my series observations. I fully calibrated each sub with the software CCDstack but it does not create the header CALSTATE=BDF so I added it manually after inputting to Vphot but before submitting the report..they're fully calibrated.


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