2011年2月，猎户座KL（Kleinmann-Low天体）H $_{2}$ O脉泽在沉寂了13年后开始爆发。这是猎户座KL第三次探测到这种现象，其次是1979-1985年和1998年。我们利用日本VLBI天体测量专用网VERA（VLBI射电天体测量探测）对猎户座KL的H $_{2}$ O脉泽爆发特征进行了天体测量观测。2011年3月，在7.58 km/s的LSR速度下，爆发特征的总通量达到4.4 $^{-1}$ Jy.爆发特征的强度比2006年静止相相同速度特征的强度大3个数量级。两个月后，2011年5月，另一个新的特征出现在6.95 km s $^{-1}$的LSR速度上，在7.58 km s $^{-1}$特征以北12 mas处分开。因此，电流突发发生在两个空间上不同的特征处。与1998年的上一次爆发一样，爆发脉泽沿西北-东南方向拉长。我们首次以亚毫角秒（mas）的精度确定了爆发特征的绝对位置。它们的位置与被称为猎户座致密脊的冲击分子气体相吻合。我们初步探测到爆发特征的绝对自行向西南方向。最有可能的是，从射电源I或另一个年轻的恒星物体与致密岭相互作用的流出是一个可能的起源H $_{2}$ O脉泽爆发。
英文摘要：
In February 2011, a burst event of the H$_{2}$O maser in Orion KL (Kleinmann-Low object) has started after 13-year silence. This is the third time to detect such phenomena in Orion KL, followed by those in 1979-1985 and 1998. We have carried out astrometric observations of the bursting H$_{2}$O maser features in Orion KL with VERA (VLBI Exploration of Radio Astrometry), a Japanese VLBI network dedicated for astrometry. The total flux of the bursting feature at the LSR velocity of 7.58 km s$^{-1}$ reaches 4.4$\times10^{4}$ Jy in March 2011. The intensity of the bursting feature is three orders of magnitudes larger than that of the same velocity feature in the quiescent phase in 2006. Two months later, another new feature appears at the LSR velocity of 6.95 km s$^{-1}$ in May 2011, separated by 12 mas north of the 7.58 km s$^{-1}$ feature. Thus, the current burst occurs at two spatially different features. The bursting masers are elongated along the northwest-southeast direction as reported in the previous burst in 1998. We determine the absolute positions of the bursting features for the first time ever with a submilli-arcsecond (mas) accuracy. Their positions are coincident with the shocked molecular gas called the Orion Compact Ridge. We tentatively detect the absolute proper motions of the bursting features toward southwest direction. It is most likely that the outflow from the radio source I or another young stellar object interacting with the Compact Ridge is a possible origin of the H$_{2}$O maser burst.
The protostar FU Orionis may not be bursting: dramatic accretion suppression in embedded young eccentric binaries
Heidelberg Institute for Theoretical Studies（海德堡理论研究所）；Research School of Astronomy & Astrophysics, Australian National University（澳大利亚国立大学天体物理与天文研究学院）
Radio Continuum and Water Maser Monitoring of the Outburst in HOPS 373: Free-Free Emission Does Not Respond to the Outburst
National Radio Astronomy Observatory（美国国家无线电天文台）；NRC Herzberg Astronomy and Astrophysics（加拿大国家研究委员会赫茨伯格天文学与天体物理学研究所）；Department of Physics and Astronomy, University of Victoria（维多利亚大学物理与天文系）；Kavli Institute for Astronomy and Astrophysics, Peking University（北京大学卡尔·萨根宇宙粒子与引力中心）；Department of Astronomy, Peking University（北京大学天文学系）；Department of Physics and Astronomy, SNUARC, Seoul National University（首尔大学SNUARC物理与天文系）；Korea Astronomy and Space Science Institute（韩国天文学与空间科学研究所）；Department of Physics and Astronomy, Seoul National University（首尔大学物理与天文系）；Research Institute of Basic Sciences, Seoul National University（首尔大学基础科学研究院）；The School of Space Research, Kyung Hee University（庆熙大学太空研究院）
