We report on the Balloon-borne Investigation of Temperature and Speed of Electrons in the corona (BITSE) mission launched recently to observe the solar corona from ≈ 3 $\approx 3$ Rs to 15 Rs at four wavelengths (393.5, 405.0, 398.7, and 423.4 nm). The BITSE instrument is an externally occulted single stage coronagraph developed at NASA’s Goddard Space Flight Center in collaboration with the Korea Astronomy and Space Science Institute (KASI). BITSE used a polarization camera that provided polarization and total brightness images of size 1024 × 1024 $1024 \times 1024$ pixels. The Wallops Arc Second Pointer (WASP) system developed at NASA’s Wallops Flight Facility (WFF) was used for Sun pointing. The coronagraph and WASP were mounted on a gondola provided by WFF and launched from the Fort Sumner, New Mexico station of Columbia Scientific Balloon Facility (CSBF) on September 18, 2019. BITSE obtained 17,060 coronal images at a float altitude of ≈ 128,000 $\approx \mbox{128,000}$ feet ( ≈ 39 $\approx 39$ km) over a period of ≈ 4 $\approx 4$ hrs. BITSE flight software was based on NASA’s core Flight System, which was designed to help develop flight quality software. We used EVTM (Ethernet Via Telemetry) to download science data during operations; all images were stored on board using flash storage. At the end of the mission, all data were recovered and analyzed. Preliminary analysis shows that BITSE imaged the solar minimum corona with the equatorial streamers on the east and west limbs. The narrow streamers observed by BITSE are in good agreement with the geometric properties obtained by the Solar and Heliospheric Observatory (SOHO) coronagraphs in the overlapping physical domain. In spite of the small signal-to-noise ratio ( ≈ 14 $\approx 14$ ) we were able to obtain the temperature and flow speed of the western steamer. In the heliocentric distance range 4 – 7 Rs on the western streamer, we obtained a temperature of ≈ 1.0 ± 0.3 $\approx 1.0\pm 0.3$ MK and a flow speed of ≈ 260 $\approx 260$ km s −1 with a large uncertainty interval.

中文翻译：

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电晕中电子温度和速度的气球携带研究 (BITSE)：任务描述和初步结果

我们报告了最近发射的日冕中电子温度和速度的气球携带调查 (BITSE) 任务，以在四种波长（393.5、405.0、398.7，和 423.4 纳米）。BITSE 仪器是美国宇航局戈达德太空飞行中心与韩国天文学和空间科学研究所 (KASI) 合作开发的外部掩蔽单级日冕仪。BITSE 使用偏振相机，提供尺寸为 1024 × 1024 $1024 \times 1024 $ 像素的偏振和总亮度图像。美国宇航局沃洛普斯飞行设施 (WFF) 开发的沃洛普斯弧秒指针 (WASP) 系统用于太阳指向。日冕仪和 WASP 安装在 WFF 提供的吊舱上，并从萨姆纳堡发射，哥伦比亚科学气球设施 (CSBF) 的新墨西哥站于 2019 年 9 月 18 日拍摄。 BITSE 在 ≈ 128,000 $\approx \mbox{128,000}$ 英尺（≈ 39 $\约 39$ 公里）的漂浮高度上获得了 17,060 张日冕图像≈ 4 $\approx 4$ 小时。BITSE 飞行软件基于 NASA 的核心飞行系统，旨在帮助开发飞行质量软件。我们在操作过程中使用 EVTM（通过遥测以太网）下载科学数据；所有图像都使用闪存存储在船上。在任务结束时，所有数据都被恢复和分析。初步分析表明，BITSE 用东西两翼的赤道飘带对太阳极小日冕进行了成像。BITSE 观测到的窄流带与太阳和日光层天文台 (SOHO) 日冕仪在重叠物理域中获得的几何特性非常吻合。尽管信噪比很小（≈ 14 $\approx 14 $），我们还是能够获得西方蒸笼的温度和流速。在西部拖缆的日心距离范围 4 – 7 Rs 中，我们获得了 ≈ 1.0 ± 0.3 $\approx 1.0\pm 0.3$ MK 和 ≈ 260 $\approx 260$ km s -1 的流速大的不确定区间。