T Pyx monitoring needed for HST observations

American Association of Variable Star Observers (AAVSO)
Thu, 09/27/2018 - 21:31

AAVSO Alert Notice 651 announces a campaign on the recurrent nova T Pyx beginning immediately. Please see the notice for details and observing instructions.

Many thanks, and Good observing,

Elizabeth O. Waagen, AAVSO HQ

American Association of Variable Star Observers (AAVSO)
T Pyx campaign - AAVSO Alert Notice 651

Hi. I've just joined the AASVO, I heard about it from Variable Star South. On VSS they mentioned a campaign (see below) to monitor T Pyx for possible HST observations. I got some data and  ran it through Astrometrica to get the magnitude - I'm unsure if this astrometry software is suitable for variable stars, if not, what is a good one?

I used a 35cm f10 Meade ACF SCT + SBIG STL11000M CCD. I took 60s expoures with a Clear filter at 2x2 binning. Sets of 5 images were stacked to get each image (observation line below) to run through Astrometrica.



CON John Drummond, Possum Observatory, Patutahi, Gisborne, New Zealand [john_drummond@xtra.co.nz]

OBS J. Drummond

MEA J. Drummond

TEL 0.35-m f/10 Schmidt-Cassegrain + CCD

ACK MPCReport file updated 2018.10.05 08:16:59

AC2 john_drummond@xtra.co.nz


     T_Pyx   KC2018 10 02.57046 09 04 41.49 -32 22 47.7          14.9V      E94

     T_Pyx   KC2018 10 02.57601 09 04 41.52 -32 22 47.5          14.9V      E94

     T_Pyx   KC2018 10 02.58156 09 04 41.50 -32 22 47.6          15.0V      E94

     T_Pyx   KC2018 10 02.64398 09 04 41.49 -32 22 47.5          14.8V      E94

     T_Pyx   KC2018 10 02.64398 09 04 41.49 -32 22 47.5          14.8V      E94

----- end -----


John Drummond, NZ, E94



AAVSO Alert Notice 651

Monitoring of T Pyx needed for HST observations

September 27, 2018: Dr. Ed Sion (Villanova University) requests AAVSO observers' assistance in monitoring the recurrent nova T Pyx, beginning immediately, in support of upcoming HST observations.

The HST COS observations have been scheduled to take place during the window of 2018 October 4 - 6. It is essential to know the status of T Pyx in order for the HST team to safeguard the instrumentation and make a final decision about approving the COS observations.

Beginning immediately, please observe T Pyx in V one to two times per night; V is preferred to other filters or unfiltered. Visual observations are welcome. It is particularly important to have positive observations available to the HST team from the nights of October 2/3, 3/4, 4/5, 5/6, and 6/7; they will make their decision 24 hours before the scheduled observation time. Please continue nightly V snapshots until October 15.

Please submit observations as soon after making them as possible to the AAVSO International Database. If T Pyx appears to be going into outburst, report observations immediately and email AAVSO (aavso@aavso.org). T Pyx is around magnitude 15.5 V at minimum, and can brighten to magnitude 6 in outburst. Observations brighter than 14.0-14.5 should be treated as a possible outburst beginning.

Coordinates:  R.A. 09 04 41.51   Dec.  -32 22 47.6   (2000.0)

Charts with a comparison star sequence for T Pyx may be created using theAAVSO Variable Star Plotter (VSP).

Please submit observations to the AAVSO International Database using the name T PYX.

AAVSO Forums: T Pyx is the topic of the AAVSO Campaigns and
Observations Reports forum thread https://www.aavso.org/t-pyx-monitor-hst-2018

and the AAVSO Novae forum thread https://www.aavso.org/t-pyx-monitor-hst-2018.

This AAVSO Alert Notice was compiled by Elizabeth O. Waagen.

Information on submitting observations to the AAVSO may be found at:


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John Drummond, Possum Observatory, IAU Code E94, Gisborne, New Zealand (177d 53' E, 38d 38' S)
Royal Astronomical Society of New Zealand Immediate-Past President - www.rasnz.org.nz
Gisborne Astronomical Society president - www.astrogas.co.nz
GAS Facebook - www.facebook.com/gisbornecosmos
Email: kiwiastronomer@gmail.com