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M dwarfs are magnetically active stars that frequently produce flares, which have implications for both stellar evolution and exoplanet studies. Flare occurrence rates and activity levels of M dwarfs correlate with stellar characteristics such as age, mass, and rotation period. We search TESS observations of a known active population of M dwarfs as well as a volume-limited sample of M dwarfs within 15 pc. We detect flares in the light curves of these stars, including 276 of 538 M dwarfs within 15 pc, and calculate cumulative flare frequency distributions (FFDs) for each star. Based on flaring behavior, we categorize stars into relatively higher- and lower-activity groups and fit power laws to their FFDs to compare the power-law exponent (α) across activity levels. We find α = 1.99 ± 0.07 for the combined FFD of the lower-activity M dwarfs, compared to averages of α = 1.94 ± 0.58 for highly active stars with 10–100 detected flares, and α = 2.03 ± 0.43 for those with >100 detected flares, suggesting little evolution in the power-law distribution of flares as M dwarfs transition from high- to low-activity states. The uncertainties for the active star groups reflect the standard deviation of α values across individual stars within each subset. Because stellar flares and associated stellar activity complicate exoplanet observations, we also examine the subset of M dwarfs with James Webb Space Telescope (JWST) transmission spectroscopy follow-up observations in Cycles 1–3. The flares we detect for these targets are consistent with the broader 15 pc sample, providing context for interpreting planetary atmosphere retrievals from JWST spectra.

Dipper stars are a classification of young stellar objects that exhibit dimming variability in their light curves, dropping in brightness by 10%–50%, likely induced by occultations due to circumstellar disk material. This variability can be periodic, quasiperiodic, or aperiodic. Dipper stars have been discovered in young stellar associations via ground-based and space-based photometric surveys. We present the detection and characterization of the largest collection of dipper stars to date: 293 dipper stars, including 234 new dipper candidates. We have produced a catalog of these targets, which also includes young stellar variables that exhibit predominately burst-like variability and symmetric variability (equal parts bursting and dipping). The total number of catalog sources is 414. These variable sources were found in a visual survey of TESS light curves, where dip-like variability was observed. We found a typical age among our dipper sources of <5 Myr, with the age distribution peaking at ≈2 Myr, and a tail of the distribution extending to ages older than 20 Myr. Regardless of the age, our dipper candidates tend to exhibit infrared excess, which is indicative of the presence of disks. TESS is now observing the ecliptic plane, which is rich in young stellar associations, so we anticipate many more discoveries in the TESS data set. A larger sample of dipper stars would enhance the census statistics of light-curve morphologies and dipper ages.

M dwarfs are magnetically active stars that frequently produce flares, which have implications for both stellar evolution and exoplanet studies. Flare occurrence rates and activity levels of M dwarfs correlate with stellar characteristics such as age, mass, and rotation period. We search TESS observations of a known active population of M dwarfs as well as a volume-limited sample of M dwarfs within 15 parsecs. We detect flares in the light curves of these stars, including 276 of 538 M dwarfs within 15 pc, and calculate cumulative flare frequency distributions (FFDs) for each star. Based on flaring behavior, we categorize stars into relatively higher and lower activity groups and fit power laws to their FFDs to compare the power law exponent (\\(\\)) across activity levels. We find \\( =1.99 0.07\\) for the combined FFD of the lower activity M dwarfs, compared to averages of \\( = 1.94 0.58\\) for highly active stars with 10-100 detected flares, and \\( = 2.03 0.43\\) for those with > 100 detected flares, suggesting little evolution in the power law distribution of flares as M dwarfs transition from high to low activity states. The uncertainties for the active star groups reflect the standard deviation of \\(\\) values across individual stars within each subset. Because stellar flares and associated stellar activity complicate exoplanet observations, we also examine the subset of M dwarfs with JWST transmission spectroscopy follow-up observations in Cycles 1-3. The flares we detect for these targets are consistent with the broader 15 pc sample, providing context for interpreting planetary atmosphere retrievals from JWST spectra.

Dipper stars are a classification of young stellar objects that exhibit dimming variability in their light curves, dropping in brightness by 10-50%, likely induced by occultations due to circumstellar disk material. This variability can be periodic, quasi-periodic, or aperiodic. Dipper stars have been discovered in young stellar associations via ground-based and space-based photometric surveys. We present the detection and characterization of the largest collection of dipper stars to date: 293 dipper stars, including 234 new dipper candidates. We have produced a catalog of these targets, which also includes young stellar variables that exhibit predominately bursting-like variability and symmetric variability (equal parts bursting and dipping). The total number of catalog sources is 414. These variable sources were found in a visual survey of TESS light curves, where dipping-like variability was observed. We found a typical age among our dipper sources of <5 Myr, with the age distribution peaking at ~2 Myr, and a tail of the distribution extending to ages older than 20 Myr. Regardless of the age, our dipper candidates tend to exhibit infrared excess, which is indicative of the presence of disks. TESS is now observing the ecliptic plane, which is rich in young stellar associations, so we anticipate many more discoveries in the TESS dataset. A larger sample of dipper stars would enhance the census statistics of light curve morphologies and dipper ages.

Young terrestrial worlds are critical test beds to constrain prevailing theories of planetary formation and evolution. We present the discovery of HD 63433d - a nearby (22pc), Earth-sized planet transiting a young sunlike star (TOI-1726, HD 63433). HD 63433d is the third planet detected in this multiplanet system. The kinematic, rotational, and abundance properties of the host star indicate that it belongs to the young (414 \\(\\) 23 Myr) Ursa Major moving group, whose membership we update using new data from Gaia DR3 and TESS. Our transit analysis of the TESS light curves indicates that HD 63433 d has a radius of 1.1 \\(R_\\) and closely orbits its host star with a period of 4.2 days. To date, HD 63433 d is the smallest confirmed exoplanet with an age less than 500 Myr, and the nearest young Earth-sized planet. Furthermore, the apparent brightness of the stellar host (V \\(\\) 6.9 mag) makes this transiting multiplanet system favorable to further investigations, including spectroscopic follow-up to probe atmospheric loss in a young Earth-sized world.

Although depressive symptoms have been linked to stroke, most research has been in relatively ethnically homogeneous, predominantly white, samples. Using the United States based Health and Retirement Study, we compared the relationships between elevated depressive symptoms and incident first stroke for Hispanic, black, or white/other participants (N = 18,648) and estimated the corresponding Population Attributable Fractions. The prevalence of elevated depressive symptoms was higher in blacks (27%) and Hispanics (33%) than whites/others (18%). Elevated depressive symptoms prospectively predicted stroke risk in the whites/other group (HR = 1.53; 95% CI: 1.36–1.73) and among blacks (HR = 1.31; 95% CI: 1.05–1.65). The HR was similar but only marginally statistically significant among Hispanics (HR = 1.33; 95% CI: 0.92–1.91). The Population Attributable Fraction, indicating the percent of first strokes that would be prevented if the incident stroke rate in those with elevated depressive symptoms was the same as the rate for those without depressive symptoms, was 8.3% for whites/others, 7.8% for blacks, and 10.3% for Hispanics.

To test whether the association between depressive symptoms and cardiovascular disease (CVD) mortality is stronger among Blacks than Whites. 2,638 Black and 15,132 White participants from a prospective, observational study of community-dwelling Health and Retirement Study participants (a nationally representative sample of U.S. adults aged > or = 50). Average follow-up was 9.2 years. Cause of death (per ICD codes) and month of death were identified from National Death Index linkages. The associations between elevated depressive symptoms and mortality from stroke, ischemic heart disease (IHD), or total CVD were assessed using Cox proportional hazards models to estimate adjusted hazard ratios (HRs). We used interaction terms for race by depressive symptoms to assess effect modification (multiplicative scale). For both Whites and Blacks, depressive symptoms were associated with a significantly elevated hazard of total CVD mortality (Whites: HR=1.46; 95% CI: 1.33, 1.61; Blacks: HR=1.42, 95% CI: 1.10, 1.83). Adjusting for health and socioeconomic covariates, Whites with elevated depressive symptoms had a 13% excess hazard of CVD mortality (HR=1.13, 95% CI: 1.03, 1.25) compared to Whites without elevated depressive symptoms. The HR in Blacks was similar, although the confidence interval included the null (HR=1.12, 95% CI: .86, 1.46). The hazard associated with elevated depressive symptoms did not differ significantly by race (P>.15 for all comparisons). Patterns were similar in analyses restricted to respondents age > or =65. Clinicians should consider the depressive state of either Black or White patients as a potential CVD mortality risk factor.

Although depressive symptoms have been linked to stroke, most research has been in relatively ethnically homogeneous, predominantly white, samples. Using the United States based Health and Retirement Study, we compared the relationships between elevated depressive symptoms and incident first stroke for Hispanic, black, or white/ other participants (N = 18,648) and estimated the corresponding Population Attributable Fractions. The prevalence of elevated depressive symptoms was higher in blacks (27%) and Hispanics (33%) than whites/others (18%). Elevated depressive symptoms prospectively predicted stroke risk in the whites/other group (HR = 1.53; 95% CI: 1.36-1.73) and among blacks (HR = 1.31; 95% CI: 1.05-1.65). The HR was similar but only marginally statistically significant among Hispanics (HR = 1.33; 95% CI: 0.92-1.91). The Population Attributable Fraction, indicating the percent of first strokes that would be prevented if the incident stroke rate in those with elevated depressive symptoms was the same as the rate for those without depressive symptoms, was 8.3% for whites/ others, 7.8% for blacks, and 10.3% for Hispanics.