NGC 6342 / C1718-195
(Updated June 2013)

RA: 17:21:10.08  DEC: -19:35:14.7  (J2000)

No known variables.
================================================================
Supplementary Notes

A CM diagram based on VI photometry by Heitsch & Richtler (1999) shows
a pronounced red HB. 
According to the 2010 version of the Harris (1996) catalogue, NGC 6342
is a core collapsed cluster with [Fe/H] = -0.55.

A binary radio pulsar PSR B1718-19 was discovered in the field of 
NGC 6342 by Lyne et al. (1993). It has an unusally long period (1 sec)
for a binary pulsar associated with a globular cluster. (Pulsars in
binary systems in  globular clusters are usually millisecond pulsars.)
van Kerkwijk et al. (2000) and Janssen & van Kerkwijk (2005) discussed 
scenarios for the formation of such a system. Their preferred
explanation is that the system formed when a dormant pulsar in the 
cluster core had an interaction with a binary.
=================================================================
References

Harris, W. E. 1996, AJ, 112, 1487

Heitsch, F. & Richtler, T. 1999, A&A, 347, 455

Janssen, T. & van Kerkwijk, M. H. 2005, A&A, 439, 433

Lyne, A. G., Biggs, J. D., Harrison, P. A., Bailes, M. 1993, Nature,
361, 47

van Kerkwijk, M. H., Kaspi, V. M., Klemola, A. R., Kulkarni, S. R.,
Lyne, A. G., van Buren, D. 2000, ApJ, 529, 428
=================================================================