The luminosity of the famous red supergiant VY CMa ( L ∼ 4− 5× 105L⊙) is well-determined from its spectral energy distribution and distance, and places it near the empirical upper luminosity limit for cool hypergiants. In contrast, its surface temperature is fundamentally ill-defined. Both contradict a recent paper by Massey, Levesque and Plez (2006). Implications for its location on the HR Dia...

Modern knowledge representation (KR), and description logics (DL) in particular, promises many advantages for information management, based on an unambiguous, implementation-independent semantics for which a range of reasoning services is available. These strengths align well with the needs of an ever growing information industry. Today, giants like Google, Facebook, and Wikimedia consciously d...

star identification is one of the most important stages in attitude determination with star trackers. this can be performed using matching algorithms between observed stars and a master star catalogue. the main challenge in this approach is to provide a fast and reliable identification algorithm that is sufficiently robust in different pointing views of the star tracker optical system in the sp...

the geographic location of the elamite terrain which lies in parts of today's khuzestan caused a middle-man-role for this region situated in between water-ways leading to the head of the persian gulf and iranian plateau and mesopotamia. in addition to the fact that this territory, possessing several rivers, was very fertile, the reality that of one of the most important iranian trade-route...

The linear adiabatic pulsation-periods of Mira variable stars have been derived. Approximately 2701[1]models were calculated for M = 0.7 MΘ to 2 MΘ stars with radii from 180 RΘ to 340 RΘ and luminosities from 2800 LΘ to 10,000 LΘ. The chemical composition of all models is (X,Z) = (0.7,0.02). From the result of this study, linear relations on Luminosity-Period-Mass relationship and luminosity-pe...

hallaj, facing different circumstances, is considered as a mysterious experience in the history and when he resisted the government, he met his dark fate and condemned to death.  the age in which hallaj lived was the real renaissance in islamic thought. massignon resembles this age with that of the fifteenth century in the west. but hallaj was economically belonged to poor rank, and scientifica...