We have used infrared images obtained with the Wide Field Camera 3 on board the Hubble Space Telescope to search for planetary-mass brown dwarfs in the star-forming cluster IC 348. In those images, we have identified 12 objects that have colors indicative of spectral types later than M8, corresponding to masses of ≲ 30 M Jup at the age of IC 348. The four brightest candidates have been observed with spectroscopy, all of which are confirmed to have late types. Two of those candidates appear to be young, and thus are likely members of the cluster, while the ages and membership of the other two candidates are uncertain. One of the former candidates is the faintest known member of IC 348 in extinction-corrected K s and is expected to have a mass of 4-5 M Jup based on evolutionary models and an assumed age of 3 Myr. Four of the remaining eight candidates have ground-based photometry that further supports their candidacy as brown dwarfs, some of which are fainter (and potentially less massive) than the known members.

中文翻译：

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IC 348 中行星质量褐矮星的新候选者

我们已经使用哈勃太空望远镜上的广角相机 3 获得的红外图像在恒星形成星团 IC 348 中搜索了行星质量的褐矮星。在这些图像中，我们已经确定了 12 个具有指示光谱颜色的物体晚于 M8 的类型，对应于 IC 348 年龄 ≲ 30 M Jup 的质量。 已经用光谱观察到了四个最亮的候选者，所有这些候选者都被证实具有晚期类型。其中两名候选人看起来很年轻，因此很可能是该集群的成员，而另外两名候选人的年龄和成员身份尚不确定。前一个候选者之一是消光校正 K s 中已知最微弱的 IC 348 成员，根据进化模型预计其质量为 4-5 M Jup，假定年龄为 3 Myr。