D. Mook, M. Kurtz, J. Weed and M. Johns report that spectra of the optical counterpart proposed for Aql X-1 have been obtained on July 29 UT with the image-tube scanner on the 132-cm telescope at the McGraw-Hill Observatory at about 6 A resolution. They confirm the appearance of emission near 4640-4650 A and 4686 A as reported by Puetter and Smith (IAUC 3243). Several spectra were obtained about 20 min apart. In some, these features were not obviously present, which may explain why van Paradijs and Remillard did not detect them with the same instrument (IAUC 3243). No H-alpha was seen on these same spectra.
International Astronomical Union Circular
- Pub Date:
- August 1978