NGC 6342 / C1718-195
(Updated June 2013)

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

============================================================
Bytes  Format      Explanation
1-8      A8        Star ID
10-32  A11,1x,A11  Position
34-35    A2        Units for position
                    R0 denotes RA, DEC in the J2000 coordinates
                    R5 denotes RA, DEC in the 1950 coordinates
                    XA denotes X, Y in arcseconds 
                    XP denotes X, Y in pixels
37-44   F8.4       Period  (days)
46-51   F6.3       Mean magnitude (or maximum magnitude if "max" 
                      is indicated in the remarks column)
53-57   F5.3       Light amplitude (range of variability)
59      A1         Colour for mean magnitude and amplitude
                    e.g.  B, V, R, I, J, K
                    or P (for photographic).
61-65   A5         Type of variable (draft 2006 GCVS classifications)
                      CST denotes non variable stars previously designated
                      as variables
67-80   A19        Notes and Remarks  (f denotes field star)
 
 "--" or "----" indicates no data available
=========================================================================
ID       Position                     Period <mag>  ampl  C Type  Notes/
         RA/X        Dec/Y     Units                              Remarks
=========================================================================
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
=================================================================