In the morning I wrote up a detailed summary of how I found the possible companion stars using Topcat. I also went through the process myself, using the mean proper motions, so I can have the exact results of what you get using them. I've already checked to make sure that the new stars that show up using the mean proper motions aren't emitting x-rays, but I wanted to have the correct lists on file anyways.
Today was the last day I could attend coffee time :( Starting tomorrow, I won't be able to come to work until around four because of double sessions of soccer try-outs. But the strawberry-smoothie I got today was amazing!
In the afternoon, Joel clarified a few background questions I had about companion stars and why they chose V4046 Sgr, MP Mus, T Cha, and TW Hya to study. It is because these stars are around 10 million years old and still have gas in their circumstellar disk, but are just starting to form planets. Usually, stars form planets and lose the gas in their circumstellar disks by 2 to 3 million years old. Therefore, there is a theory that these widely separated companion stars (like TWA 28) were once very close to, in this case, TW Hya, and prevented it from forming planets until now. I made a slide for this info in my powerpoint.
Things are looking good for 2M1155-79, the possible companion for T Cha. Rudy continues to analyze the spectrum and he found a small absorption which is good because that means the star doesn't have a disk (most companions don't). Joel is going to ask his friend in Australia if he will extract the spectrum using his telescope, so we can see if it has Li absorption (indication of a young star).