Alert Notice 567: IM Nor monitoring requested for HST COS observations

February 10, 2017: Dr. Ed Sion (Villanova University) and colleagues have requested AAVSO observers' assistance in monitoring the symbiotic-type recurrent nova IM Nor in support of observations with the Hubble Space Telescope Cosmic Origins Spectrograph scheduled for 2017 February 13 - 17 UT.

These observations are part of a study on short orbital period recurrent novae as Supernovae Type Ia progenitors.

It is essential to know 24 hours prior to the HST COS observations that IM Nor is not in outburst, in order to protect the instrumentation. Also, photometry is needed throughout the HST window to insure knowledge of the brightness of the system.

Observers are asked to monitor IM Nor with nightly snapshot images (V preferred) from now through February 20, and to report their observations promptly. It will be especially important to know the brightness of IM Nor each night through February 17 UT.

The AAVSO comparison star sequence for IM Nor has been extended so that IM Nor itself, which is V ~ 18.5 at minimum, can be imaged without saturating the faintest comparison stars. Stacking may be necessary to visualize IM Nor. Visual observations, if feasible, are welcome.

In its original outburst, IM Nor (Nova Nor 1920) reached V ~ 8.5, as it did in 2002, the year of its only recurrent outburst observed to date.

Coordinates for IM Nor:  R.A. 15 39 26.42   Dec. -52 19 17.9   (2000.0)

Charts: Charts with a comparison star sequence for IM Nor may be created using the AAVSO Variable Star Plotter (VSP).

Please submit observations promptly to the AAVSO International Database using the name IM NOR. If you see IM Nor brightening, contact AAVSO Headquarters immediately.

This campaign is being monitored on the AAVSO Observing Campaigns webpage and is being followed on the Campaigns and Observation Reports Forum at

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


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