A Possible Period for the K-band Brightening Episodes of GX 17+2

TL;DR

This paper identifies a potential 3.01254-day periodicity in the infrared K-band brightening episodes of GX 17+2, suggesting a possible link to jet activity, with implications for predicting future episodes.

Contribution

It reports the first evidence of a consistent period in K-band brightening episodes of GX 17+2 and provides an ephemeris for predicting future events.

Findings

Brightening episodes last at least 4 hours.

Periodicity of 3.01254 days identified.

Potential connection to synchrotron jet activity.

Abstract

The low mass X-ray binary and Z source GX 17+2 undergoes infrared K-band brightening episodes of at least 3.5 magnitudes. The source of these episodes is not known. Prior published K-band magnitudes and new K-band measurements acquired between 2006 and 2008 suggest that the episodes last at least 4 hours and have a period of 3.01254 $\pm$ 0.00002 days. Future bright episodes can be predicted using the ephemeris JD_{max} (n) = 2454550.79829 + (3.01254 $\pm$ 0.00002)(n) days. A growing body of evidence suggests that the GX 17+2 could have a synchrotron jet, which could cause this activity.