Gravity modes in the Sun have been long searched during the past decades. Using their asymptotic properties Garcia et al. (2007) found the signature of the dipole g modes analyzing an spectral window between 25 and 140 muHz of velocity power spectrum obtained from the GOLF/SoHO instrument. Using this result it has been possible to check some properties of the structure of the solar interior (Garcia, Mathur & Ballot 2008) as well as some indications on the dynamics of the core. However, the individual detection of such modes remains evasive and they are needed to really improve our knowledge of the deepest layers in the Sun (Mathur et al. 2008). In this work we study the signal at 220.7 muHz which is present in most of the helioseismic instruments during the last 10 years. This signal has been previously identified as part of a g-mode candidate in the GOLF data (Turck-Chieze et al. 2004; Mathur et al. 2007) and in SPM/VIRGO (Garcia et al. 2008) with more than 90% confidence level. It could be labelled as the l=2 n=-3 g mode as it is in the region were this mode is expected.
We have checked the possibility that the 220.7 muHz signal could have an instrumental origin without success by analysing all the available housekeeping data as well as the information on the roll, pith and yaw of the SoHO spacecraft. In consequence, we are confident that this signal has a solar origin.
Phase Coherence Analysis of Solar Magnetic Activity
来自国家空间局基特峰真空望远镜的24年以上的天气数据被用来调查在各种与太阳有关的时间序列中的多个太阳周期中观察到的27天（会合）周期的一致性和来源。Neugebauer等人（2000）最近报道了一个强的27.03天周期信号，该信号在868.8 nm Fe I线的磁通量和1083.0 nm He I线的线等效宽度的积分全磁盘测量的时间序列的功率谱中被清楚地检测到。通过对光球磁场的天气图进行谱分析，除了构造活动的表面分布图之外，我们发现27.03天信号的起源是北半球纬度约18度的活动区的长寿命复合体。此外，使用一种新的时间序列分析技术，利用信号的相位方差，27.03天周期的信号的相干性被发现是显着的，在过去的二十年。然而，使用过去120年的太阳黑子数时间序列，发现27.03天周期的信号是一个短暂的，不长于两个11年的太阳周期，准平稳信号。
Interaction between a fast rotating sunspot and ephemeral regions as the origin of the major solar event on 2006 December 13
2006年12月13日的主要太阳事件的特征是几乎同时发生的一堆热喷出物，一个巨大的双带耀斑和一个扩展的地球定向日冕物质抛射。我们研究了活动区NOAA AR 10930的磁场和太阳黑子的演化，这是事件的源区，而它从12月10日到12月13日经过太阳盘中心。我们发现，与这次事件有关的活动区的明显变化是磁剪切的发展，短暂区的出现和一个较小的太阳黑子的快速旋转。在活动区的磁中性线附近，快速旋转的黑子与短暂区之间的相互作用触发了持续增亮，最终导致大耀斑。这表明，只有在太阳黑子旋转到200 $^{\circ}$之后，才会发生重大事件。太阳黑子围绕其中心旋转至少240 $^{\circ}$，这是已报道的最大太阳黑子旋转角。
