Evidence for a black hole in the X‐ray transient XTE J1859+226
We present the results of time‐resolved optical photometry and spectroscopy of the X‐ray transient XTE J1859+226 (V406 Vul). Photometric observations taken...
HST emission line images of the Orion HII region: proper motions and possible variability
Using HST emission line images of the Orion Nebula, separated by 7 years in epoch, we have obtained evidence of localized temporal variability of both density...