# Tag Info

1

The radius of the planet is 0.17% of Jupiter's radius. Under the "Planet" info on the left, it says $R_P$ which is the radius of planet, and since the units are shown as $[R_J]$ this is the value is in comparison to Jupiter. It also gives the $M_P$ (mass of planet) in relation to $M_J$ (mass of Jupiter) as well. The interesting thing here is the ...

0

There is only one dip in flux recorded. No, it seems to be a folded light curve that may include of the order of a thousand cycles, must include at least a few cycles since the uncertainty given for the period on that page is roughly one part per thousand since a period is given: Period [day]: 0.736539 ± 8.7e-4 Demory et al. 2016 Transit ...

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In general, you can't. The spectroscopy tells you about the properties of the star and the properties of the orbit and gives some information about the mass of the planet ($M \sin i$, where $i$ is the orbital inclination). If the spectroscopy were super-precise and with extremely high signal-to-noise and high time resolution, then you might be able to map ...

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The color index of the star can give you that information. I can look it up for you if I know which exoplanet you're interested in, or you can find it in the NASA Exoplanet Database here.

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The advantages of using Julian dates (and what to do with the "- 2450000" part) have been described well in previous answers but if you're curious about the "barycentric" part here's an example. Let's say I'm observing an eclipsing binary to measure the period which might be changing. Six months later I observe the system again. The ...

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For an authoritative source of data on exoplanets, your best bet is the NASA Exoplanet Archive. Their page for HD 219134b is here. For planet spectra, the archive has a page for planets with transit spectroscopy, but searching that page for HD 219134 yields no results. Note that transit spectroscopy is challenging, so there aren't very many planets to ...

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Julian dates offer one nice feature: All astronomical observations recorded by humankind have a positive timestamp. A key downside of Julian dates is that current timestamps on computers that use 64 bit IEEE Standard for Floating-Point Arithmetic (IEEE 754) have a resolution of 40 microseconds. Almost all computers use the IEEE 754 floating point standard. ...

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That is a simple offset in order to work with smaller numbers. Add that number (2450000) again to each value in the day column and you have the unmodified value of BJD.

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