Exoplanet Detection and Atmospheric Characterization

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1. 1

   Which exoplanet detection method searches for periodic decreases in a star's observed brightness?

   A Radial-velocity method B Transit method C Astrometric method
2. 2

   The image shows a 1% transit depth for a planet crossing a Sun-sized star. Approximately which planet size does this indicate?

   

   A Earth-sized B Neptune-sized C Jupiter-sized
3. 3

   What does the radial-velocity method measure to infer the presence of an orbiting planet?

   A Periodic Doppler shifts in the star's spectrum B Periodic changes in the star's chemical composition C Radio signals reflected by the planet
4. 4

   In the image, an observed stellar absorption line is shifted toward shorter wavelengths relative to its rest position. What does this indicate?

   

   A The star is moving away from the observer B The star is moving toward the observer C The star has stopped rotating
5. 5

   Which planetary system is generally most favorable for direct imaging with current instruments?

   

   A An old rocky planet orbiting extremely close to a bright star B A small planet whose orbit is hidden directly behind its star C A young, massive planet orbiting far from its star
6. 6

   Which feature in the illustrated microlensing light curve most strongly suggests the presence of a planet around the lens star?

   

   A A short anomaly superimposed on the main smooth brightening B A permanent reduction in the background star's brightness C A uniform color change lasting for many orbital periods
7. 7

   How is a transiting planet's orbital period usually determined from its light curve?

   A From the duration of a single transit alone B From the time interval between successive transits C From the depth of the transit
8. 8

   Why does radial-velocity detection usually provide a planet's minimum mass rather than its exact mass?

   A The host star's mass can never be estimated B Planetary atmospheres absorb part of the Doppler signal C The signal depends on the unknown orbital inclination
9. 9

   What important physical property can be calculated when both a planet's transit radius and radial-velocity mass are known?

   A Average density B Exact surface composition C Age independent of the host star
10. 10

    In the illustrated transit geometry, how can astronomers obtain a transmission spectrum of the planet?

    

    A By measuring only light reflected from the planet's night side B By analyzing starlight filtered through the planet's atmospheric edge C By measuring gravitational waves from the orbit
11. 11

    The displayed exoplanet spectrum contains dark troughs at several molecule-specific wavelength bands. What primarily produces these features?

    

    A Changes in the planet's orbital period B Uniform reflection at all wavelengths C Absorption of selected wavelengths by atmospheric molecules
12. 12

    What is the conventional definition of a star's habitable zone?

    A The orbital region where surface liquid water could be possible under suitable atmospheric conditions B The region where every planet must contain life C The region where planets have the same year length as Earth
13. 13

    Which astrophysical system can mimic a planetary transit and therefore create a false positive?

    A A distant solitary neutron star outside the image B A blended or grazing eclipsing binary star system C A star with no brightness variability
14. 14

    What can transit-timing variations reveal in a multiplanet system?

    A The exact chemical composition of the host star's core B The planet's surface color without imaging it C Gravitational interactions with additional planets
15. 15

    Which detection technique is represented by the star tracing a tiny repeated path across the sky in the image?

    

    A Astrometry B Transmission spectroscopy C Transit photometry
16. 16

    The image shows a planet's brightness changing continuously over one orbit. What can such a phase curve help astronomers map?

    

    A The mineral structure of the planet's deep core B Longitudinal differences in atmospheric brightness or temperature C The exact number of impact craters on the surface
17. 17

    What information is isolated by comparing a star-planet system's light immediately before and during the planet's secondary eclipse?

    A Only the host star's distance from Earth B Only the planet's gravitational effect on the star C The planet's dayside thermal emission and reflected light
18. 18

    Why do transit surveys detect disproportionately many large planets with short orbital periods?

    A They produce deeper, more frequent transits and have higher transit probabilities B Small and distant planets cannot orbit stars C All planetary systems naturally contain only short-period giants
19. 19

    What exoplanetary property is primarily measured through the Rossiter-McLaughlin effect illustrated in the image?

    

    A The planet's internal magnetic-field strength B The projected alignment between the stellar spin and planetary orbit C The planet's radioactive-element abundance
20. 20

    Which observation would provide the strongest atmospheric biosignature evidence while still requiring careful confirmation?

    A Detection of a single common molecule at low confidence B A planet located in the habitable zone with no atmospheric spectrum C Multiple gases in strong chemical disequilibrium, supported by planetary context