Friday, July 10, 2015

Part VII : High Precision Photometry of Transiting Exoplanets as I currently know it

In Part IV, I posed the following questions but forgot to give my brief answer for it:
"So, how does MINERVA (a ground-based observatory) differ from the Kepler Mission?  Furthermore, why am I looking for 'High Precision' measurements from this MINERVA observatory and not the space-based Kepler data?  "

Both telescopes have a purpose to detect exoplanets.  When discerning that Kepler is a space-based telescope and MINERVA is ground-based, your first impression might be that Kepler is better than MINERVA.  However here are a few facts about MINERVA that indicate why it is simply different than Kepler as opposed to being inferior:
  • A multi-telescope array allows for simultaneous exposure of primary bright star and its comparison stars (for which satisfactory comparison stars may sometimes not be in the same field of view for 1 telescope alone).
    • Despite how related this concept is to my project specifically, this concept is also very related to differential photometry research in general.  Differential photometry is an immensely beneficial and widely used form of research. I think it's cool that an observatory was made to ameliorate this form of research practice.

  • A primary purpose of MINERVA is to ALWAYS achieve a measured Doppler Shift precision of 0.8 m/s or less.
    • Radial Velocity Curves will have small error bars! 
    • This is great for confirming exoplanet candidates as true exoplanet detections that have been observed by Kepler.
    • This is also great for confirming false-positive exoplanet detections made by Kepler.  A false-positive detection is when the measurements seem to infer that an exoplanet was observed, however after further observations and/or analysis that object was verified to be something else--such as an eclipsing binary star.

  • MINERVA was also built for being capable of detecting super-Earths (exoplanets with 2-5R\(_{\oplus}\))  within their respective habitable zones.  After being detected with radial velocity measurements, these super-Earths can be characterized further with multi-band photometry.  This feat requires a broadband photometric precision < 1 mmag in the optical wavelengths.
    • Aside: remember R\(_{\oplus}\) represents 1 Earth's radius as if it is a unit of measurement, like the meter.  It is a convenient way to compare the size of other objects to an object (the Earth) that we are familiar with. Furthermore, I will elaborate on multi-band photometry and 1 mmag precision at a later time.

  • Now that MINERVA can do such a great job at confirming exoplanet candidates initially observed by Kepler, humanity can move quicker in finding planets that may already harbor Life.  Surely, planets that have satisfactory conditions to sustain life will be the first among a list of destinations that astronauts will travel to when long distance space travel becomes more common and feasible.

  • Another primary purpose of MINERVA is to detect and confirm exoplanets with small radii.  This is difficult to do because of how small the "dip" of a light curve is for small transiting exoplanets.  In Part IV,  I stated "there are more planets with a radius < 4R\(_{\oplus}\) than there are larger ones in our Milky Way Galaxy.  This means that a project dedicated to finding exoplanets should certainly be equipped to find planets with a relatively small radius (~Earth size) and low mass."
    • This is one reason why the MINERVA project is so focused on achieving high precision measurements.

  • It's a ground based telescope.  It costs MUCH less to construct.  It costs MUCH less operate.  Therefore... More astronomers have access to use it for their specific research purposes.  This means students of all ages have a better chance at earning time on this telescope for their research needs as well!
How great is it that I, an undergraduate, can use highly sophisticated technology partially owned by Harvard University to conduct research that will actually benefit the astronomy community at large!  It is because of the access that telescopes like MINERVA provide to the younger astronomy community that makes a young person like me be able to make discoveries that are actually relevant and significant to this well-respected field of highly-educated philosophers of the Universe. Yay! for Opportunity.  And speaking of "access", the MINERVA (Planewave CDK 0.7m) telescopes were made to be wheelchair accessible.  Yay! for social justice and awareness of abilism.  Yay! for the astronomy community respecting the ideas and research of its youngest members.

Sorry for the spontaneous outbursts of celebrations.  I guess I was in a grateful mood.  I think now is as good of a time as any to tweet what the Adler Planetarium deems #science4everyone.

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