标题： 2011年再发新星天蝎座T的爆发；发现、爆发前的上升、爆发前的轨道周期以及长期延迟的原因 显示英文标题

标题： The 2011 Eruption of the Recurrent Nova T Pyxidis; the Discovery, the Pre-eruption Rise, the Pre-eruption Orbital Period, and the Reason for the Long Delay

摘要： 我们报告M. Linnolt在JD 2455665.7931（UT 2011年4月14日29时）发现食双星T Pyxidis的第六次爆发。这次发现是在初始快速上升刚开始时做出的，因此全球观测者的快速通知和响应覆盖了整个初始上升阶段（这是任何新星的第一个），并且在三个滤镜中具有高时间分辨率。上升速度达到每天空9星等，而光曲线仅在前两天由一个均匀膨胀的球体模型很好地拟合。我们还报告R. Stubbings发现爆发前的上升开始于爆发前18天，比其长期平均亮度高1.1星等，然后在爆发前4天恢复到休眠状态。这种独特而神秘的行为是已知的第四次在新星爆发前紧密间隔的预期上升。我们从1986年至2011年2月提供了19次光度最小值的时间，其中轨道周期以P/dot{P}=313,000年加快。从2008年至2011年，T Pyx在此增加率上有小幅变化，因此爆发时的轨道周期为0.07622950+-0.00000008天。轨道周期的这种强烈且稳定的增加只能来自质量转移，我们计算出的质量转移速率为1.7-3.5x10^-7 Mo/yr。我们报告了从1890年至2011年的6116个星等，1967年至2011年的平均B=15.59+-0.01，这允许在2011年爆发，如果蓝光通量几乎与吸积率成正比。紫外-光学-红外光谱能量分布由一个通量与nu^1.0成比例的幂律很好地拟合，尽管窄紫外区域有一个倾斜，拟合为\nu ^{1/3}。我们证明了T Pyx的大部分光不是来自盘，或任何黑体的叠加，而是来自某种非热源。 显示英文摘要

摘要： We report the discovery by M. Linnolt on JD 2455665.7931 (UT 2011 April 14.29) of the sixth eruption of the recurrent nova T Pyxidis. This discovery was made just as the initial fast rise was starting, so with fast notification and response by observers worldwide, the entire initial rise was covered (the first for any nova), and with high time resolution in three filters. The speed of the rise peaked at 9 mag/day, while the light curve is well fit over only the first two days by a model with a uniformly expanding sphere. We also report the discovery by R. Stubbings of a pre-eruption rise starting 18 days before the eruption, peaking 1.1 mag brighter than its long-time average, and then fading back towards quiescence 4 days before the eruption. This unique and mysterious behavior is only the fourth known anticipatory rise closely spaced before a nova eruption. We present 19 timings of photometric minima from 1986 to February 2011, where the orbital period is fast increasing with P/dot{P}=313,000 yrs. From 2008-2011, T Pyx had a small change in this rate of increase, so that the orbital period at the time of eruption was 0.07622950+-0.00000008 days. This strong and steady increase of the orbital period can only come from mass transfer, for which we calculate a rate of 1.7-3.5x10^-7 Mo/yr. We report 6116 magnitudes between 1890 and 2011, for an average B=15.59+-0.01 from 1967-2011, which allows for an eruption in 2011 if the blue flux is nearly proportional to the accretion rate. The ultraviolet-optical-infrared spectral energy distribution is well fit by a power law with flux proportional to nu^1.0, although the narrow ultraviolet region has a tilt with a fit of \nu^{1/3}. We prove that most of the T Pyx light is not coming from a disk, or any superposition of blackbodies, but rather is coming from some nonthermal source.