Sternbilders have a chat channel on Rizon IRC (Internet Relay Chat) network. You can access it via webchat or by using IRC clients such as mIRC, Chatzilla for Firefox, or Mibbit which works in any browser.
Easiest and fastest way to join the chat is to use Mibbit – just pick a nickname and join the channel. There is no password.
(The channel is also a fast way to get in touch with us, derpchan is usually idling there, you can recognise her by the “~” in front of her nickname.)