Warning on macOS Upgrade to Catalina

Apple has recently released macOS version Catalina (10.15.1).  This version of macOS no longer supports 32-bit software such as parts of IRAF and IDL.  Additionally, we have found that the vncviewer software (Real VNC and Tiger VNC) that we commonly use for remote observing at SOAR is affected by this.  The vnc viewer Chicken claims to be 64-bit compliant and working with Catalina, but it has not been tested by us.  Therefore, we recommend that our macOS users do not upgrade to Catalina until further notice.  This does not affect our remote observers using GNU/Linux OS or Microsoft Windows OS.