We present a flare star catalog from 4 yr of nontargeted millimeter-wave survey data from the South Pole Telescope (SPT). The data were taken with the SPT-3G camera and cover a 1500 deg² region of the sky from 20^h40^m0^s to 3^h20^m0^s in right ascension and from −42° to −70° in declination. This region was observed on a nearly daily cadence from 2019 to 2022 and chosen to avoid the plane of the galaxy. A short-duration transient search of this survey yields 111 flaring events from 66 stars, increasing the number of both flaring events and detected flare stars by an order of magnitude from the previous SPT-3G data release. We provide cross-matching to Gaia DR3, as well as matches to X-ray point sources found in the second ROSAT all-sky survey. We have detected flaring stars across the main sequence, from early-type A stars to M dwarfs, as well as a large population of evolved stars. These stars are mostly nearby, spanning 10–1000 pc in distance. Most of the flare spectral indices are constant or gently rising as a function of frequency at 95/150/220 GHz. The timescale of these events can range from minutes to hours, and the peak ν L _ν luminosities range from 10²⁷ to 10³¹ erg s⁻¹ in the SPT-3G frequency bands.

中文翻译：

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使用 SPT-3G 进行非目标毫米波巡天中的耀斑恒星


我们提供了来自南极望远镜 (SPT) 4 年非目标毫米波勘测数据的耀斑星表。这些数据是用 SPT-3G 相机拍摄的，覆盖了 20 ^h 40 ^m 0 ^s到 3 ^h 20 ^m 0 ^s赤经和 -42° 到 -70° 赤纬的 1500 deg ²天空区域。从 2019 年到 2022 年，人们几乎每天都会对该区域进行观测，并选择避开银河系平面。此次调查的短期瞬态搜索产生了来自 66 颗恒星的 111 个耀斑事件，与之前发布的 SPT-3G 数据相比，耀斑事件和检测到的耀斑恒星的数量增加了一个数量级。我们提供与 Gaia DR3 的交叉匹配，以及与第二次 ROSAT 全天巡天中发现的 X 射线点源的匹配。我们已经在主序带上检测到了耀斑恒星，从早期的 A 型恒星到 M 型矮星，以及大量的演化恒星。这些恒星大多都在附近，距离为 10-1000 pc。大多数耀斑光谱指数是恒定的或作为 95/150/220 GHz 频率的函数缓慢上升。这些事件的时间范围从几分钟到几小时不等，高峰期ν L _ν SPT-3G 频段的光度范围为 10 ²⁷至 10 ³¹ erg s ^-1 。