Maxim Barkov and Alexei Pozanenko , Model of the extended emission of short gamma-ray bursts , Mon . ... The existence of extended emission (EE) is an intriguing property of short-duration gammaray bursts, because the nature of the EE is still unclear. ... We consider short duration gamma-ray bursts, emphasizing the common properties of both short bursts and short bursts with EE. ... Our proposed model is a plausible mechanism for short-duration burst energization . ...

... At the summer date, at the chosen time, the Sun is high in the sky. at point S, while at the winter date, it is low in the sky, at point W. The shadow of the gnomon is always in the plane containing the Sun and the points A and B. If AB is a thin line, the shadow will also be a thin line, the intersection of this plane with the base of the sundial. ... Summer or winter, the shadow is therefore along the same line, the intersection of the above plane and the base of the sundial. ...

Educator's Guide to Impact Craters . ... Just about all craters have deep central depressions, raised rims, and a blanket of ejected material surrounding them. ... Look for classical cratering features: basin, raised rim, ejecta blanket (material excavated from the crater and dumped around it, visible as white flour on the colored powder), and rays (material shot out at high velocity forming lines pointing directly away from the impact site). ... The material lies like a blanket around the crater. ...

Cosmic Research, Vol. 42, No. 5, 2004, pp. 435­488. Translated from Kosmicheskie Issledovaniya, Vol. 42, No. 5, 2004, pp. 453­508. Original Russian Text Copyright © 2004 by Veselovsky, Panasyuk, Avdyushin, Bazilevskaya, Belov, Bogachev, Bogod, Bogomolov, Bothmer, Boyarchuk, Vashenyuk, Vlasov, Gnezdilov, Gorgutsa, Grechnev, Denisov, Dmitriev, Dryer, Yermolaev, Eroshenko, Zherebtsov, Zhitnik, Zhukov, Zastenker, Zelenyi, Zeldovich, Ivanov-Kholodnyi, Ignat'ev, Ishkov, Kolomiytsev, Krasheninnikov, Kudela,