8 research outputs found

    TESS discovery of a super-Earth and two sub-Neptunes orbiting the bright, nearby, Sun-like star HD 22946

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    We report the Transiting Exoplanet Survey Satellite (TESS) discovery of a three-planet system around the bright Sun-like star HD~22946(V=8.3 mag),also known as TIC~100990000, located 63 parsecs away.The system was observed by TESS in Sectors 3, 4, 30 and 31 and two planet candidates, labelled TESS Objects of Interest (TOIs) 411.01 (planet cc) and 411.02 (planet bb), were identified on orbits of 9.57 and 4.04 days, respectively. In this work, we validate the two planets and recover an additional single transit-like signal in the light curve, which suggests the presence of a third transiting planet with a longer period of about 46 days.We assess the veracity of the TESS transit signals and use follow-up imaging and time series photometry to rule out false positive scenarios, including unresolved binary systems, nearby eclipsing binaries or background/foreground stars contaminating the light curves. Parallax measurements from Gaia EDR3, together with broad-band photometry and spectroscopic follow-up by TFOP allowed us to constrain the stellar parameters of TOI-411, including its radius of1.157±0.025R⊙1.157\pm0.025R_\odot. Adopting this value, we determined the radii for the three exoplanet candidates and found that planet bb is a super-Earth, with a radius of 1.72±0.10R⊕1.72\pm0.10R_\oplus, while planet cc and dd are sub-Neptunian planets, with radii of2.74±0.14R⊕2.74\pm0.14R_\oplus and 3.23±0.19R⊕3.23\pm0.19R_\oplus respectively. By using dynamical simulations, we assessed the stability of the system and evaluated the possibility of the presence of other undetected, non-transiting planets by investigating its dynamical packing. We find that the system is dynamically stable and potentially unpacked, with enough space to host at least one more planet between cc and dd.(Abridged)Comment: 21 pages, 12 figures. Accepted for publication on A&

    UNMC acts to draw more blacks A partnership with schools in Virginia is to serve as a model in attracting minorities to health care jobs. Black enrollment at University of Nebraska Medical Center

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    The University of Nebraska Medical Center joined forces Wednesday with five historically black schools and a community college, all in Virginia, to bring more minority students to the Omaha campus. Under the new program, UNMC and Virginia Commonwealth University will provide a variety of academic and research opportunities for minority undergraduate students and faculty members

    UNMC acts to draw more blacks A partnership with schools in Virginia is to serve as a model in attracting minorities to health care jobs. Black enrollment at University of Nebraska Medical Center

    No full text
    The University of Nebraska Medical Center joined forces Wednesday with five historically black schools and a community college, all in Virginia, to bring more minority students to the Omaha campus. Under the new program, UNMC and Virginia Commonwealth University will provide a variety of academic and research opportunities for minority undergraduate students and faculty members

    A Uniform Search for Nearby Planetary Companions to Hot Jupiters in TESS Data Reveals Hot Jupiters Are Still Lonely

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    Abstract We present the results of a uniform search for additional planets around all stars with confirmed hot Jupiters observed by the Transiting Exoplanet Survey Satellite (TESS) in its Cycle 1 survey of the southern ecliptic hemisphere. Our search comprises 184 total planetary systems with confirmed hot Jupiters with R p &gt; 8 R ⊕ and orbital period &lt;10 days. The Transit Least Squares algorithm was utilized to search for periodic signals that may have been missed by other planet search pipelines. While we recovered 169 of these confirmed hot Jupiters, our search yielded no new statistically validated planetary candidates in the parameter space searched (P &lt; 14 days). A lack of planet candidates nearby hot Jupiters in the TESS data supports results from previous transit searches of each individual system, now down to the photometric precision of TESS. This is consistent with expectations from a high-eccentricity migration formation scenario, but additional formation indicators are needed for definitive confirmation. We injected transit signals into the light curves of the hot Jupiter sample to probe the pipeline’s sensitivity to the target parameter space, finding a dependence proportional to R p 2.32 P − 0.88 for planets within 0.3 ≀ R p ≀ 4 R ⊕ and 1 ≀ P ≀ 14 days. A statistical analysis accounting for this sensitivity provides a median and 90% confidence interval of 7.3 − 7.3 + 15.2 % for the rate of hot Jupiters with nearby companions in this target parameter space. This study demonstrates how TESS uniquely enables comprehensive searches for nearby planetary companions to nearly all the known hot Jupiters.</jats:p
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