D. Reiss, University of Washington, and the Mt. Stromlo Abell Cluster Supernova Search Team (cf. IAUC 7106) report the discovery of a supernova (V about 18.2, R about 18.4) on a CCD image obtained on Mar. 3 by S. Sabine with the Mt. Stromlo 1.27-m telescope (+ Macho Camera). SN 1999ao is located near Abell 3392 at R.A. = 6h27m26s.37, Decl. = -35o50'24".2 (equinox 2000.0), which is 2".3 west and 0".9 north of the nucleus of the host galaxy; a nearby star has position end figures 27s.34, 51'09".3. SN 1999ao is not visible on similar frames taken on Jan. 10 (limiting mag 20.5). CCD UBVRI images obtained at the Cerro Tololo 0.9-m telescope on Mar. 8 and 9 by L. Germany also show the new star. A spectrum (range 320-900 nm) taken by B. Schmidt at the Australian National University's 2.3-m telescope on Mar. 10.5 UT shows that SN 1999ao is a type-Ia event, about 8 days before maximum brightness; its redshift (z = 0.054), obtained from Ca H and K features, is nearly identical to that of Abell 3392 (z = 0.055).
International Astronomical Union Circular
- Pub Date:
- March 1999