GM Sgr rapid variation GM Sgr, an outbursting object of unknown type, is reported to show remarkable short-term variation. Frequent observations are strongly urged. YYMMDD(UT) mag observer 990829.424 127 (R. Stubbings) 990831.478 <131 (T. Watanabe) 990831.496 130 (R. Stubbings) 990909.462 112 (R. Stubbings) 990910.414 112 (R. Stubbings) 990910.474 112 (R. Stubbings) 990911.599 119 (R. Stubbings) 990912.409 111 (R. Stubbings) 990912.460 115 (T. Watanabe) 990912.476 112 (R. Stubbings) 990913.397 119 (R. Stubbings) 990913.730 123 (B. Monard) 990914.715 117 (B. Monard) 990914.749 114 (B. Monard) 990914.776 111 (B. Monard) 990914.787 111 (B. Monard)