Dippers from the TESS Full-frame Images. I. Results of the First One Year Data and Discovery of a Runaway Dipper

We present a comprehensive catalog of the dippers-young stellar objects that exhibit episodic dimming-derived from one year's worth of data of the Transiting Exoplanet Survey Satellite (TESS) full-frame images. In the survey, we found 35 dippers using the convolutional neural network, most of them newly discovered. Although these dippers are widely distributed over the first half-hemisphere that TESS surveyed, we identified the majority's membership with the nearest association Scorpius-Centaurus, Velorum OB2, and the nearby Orion molecular cloud complex. However, several dippers are likely to be located in the field. We also found three old dippers whose age exceeds 10 million years, which is considered to be the disk dissipation time. The color-color diagram indicates that these old dippers are likely to have an extreme debris disk. In particular, we found a runaway old dipper having a large three-dimensional velocity of 72 km s(-1). The dippers in the field, which were probably escaping from their birth molecular clouds or were born outside the current area of star-forming regions, are more common than previously considered.