https://www.kimbott.com/research daily 1.0 2023-10-16 https://images.squarespace-cdn.com/content/v1/582a1d1f46c3c4d32caf6827/f089c23a-b6b1-45e5-b51b-13635c578f42/Screen+Shot+2023-08-02+at+11.37.27+AM.png Research - Make it stand out An example of the phase curves of a vaguely Earth-like planet with visible water clouds and ocean glint forming peaks that change in relative shape with wavelength. Note that at most wavelengths, more structure is seen in the polarized phase curve (lower panel) than the unpolarized/classic photometry phase curve (top panel), illustrating how the polarization might be used to more fully characterize these features. From Vaughan, Gebhard, Bott+ 2023 https://images.squarespace-cdn.com/content/v1/582a1d1f46c3c4d32caf6827/1482348659016-IPVLQ89AEQDB7QDQRWNV/BaileyGroupAAT.jpg Research The HiPPI commissioning team in the AAT control room. L-to-R: Jeremy Bailey, Lucyna Kedziora-Chudczer, Daniel Cotton, Kim Bott https://images.squarespace-cdn.com/content/v1/582a1d1f46c3c4d32caf6827/1482348600482-IUVZCQCLVONFMIR89JMB/ESOpol.jpg Research https://images.squarespace-cdn.com/content/v1/582a1d1f46c3c4d32caf6827/1482348902954-71X58KZY1B0TAPBYBP5B/reddwardwater.jpg Research https://images.squarespace-cdn.com/content/v1/582a1d1f46c3c4d32caf6827/1482349036659-WH1RXV99YA4582TZ2WYY/hidefHD189.jpg Research https://www.kimbott.com/blog daily 0.75 2021-02-10 https://www.kimbott.com/blog/2021/2/9/the-first-detection-of-an-exoplanet-with-polarimetry monthly 0.5 2021-02-10 https://images.squarespace-cdn.com/content/v1/582a1d1f46c3c4d32caf6827/1612933456743-STQSBDP1MGEC5C7CDULR/Screen+Shot+2021-02-09+at+6.59.31+PM.png Research Blog - The First Detection of an Exoplanet with Polarimetry? The data (black) for four hot Jupiter systems observed with HIPPI/-2 presented in this paper compared to their best fit Rayleigh-Lambert phase curves. HD 179949 and Tau Boo in the top panels do not have any reported trends. However, HD 189733 (bottom left) seems to show polarization due to stellar activity, and 51 Peg (bottom right) possibly shows polarization from the planet itself. https://images.squarespace-cdn.com/content/v1/582a1d1f46c3c4d32caf6827/1612927295875-3494MHGC46UBPTA11ZNW/image-asset.jpeg Research Blog - The First Detection of an Exoplanet with Polarimetry? https://images.squarespace-cdn.com/content/v1/582a1d1f46c3c4d32caf6827/1612933710879-CUWITNF9QI9N2NU2KHOQ/Screen+Shot+2021-02-09+at+7.01.12+PM.png Research Blog - The First Detection of an Exoplanet with Polarimetry? The data taken over several years overlaid for the four systems considered in the paper. On the left is the data with the data reduction technique used in our previous HIPPI team papers and on the right with an improved approach. See the paper for details. https://www.kimbott.com/blog/2018/11/5/the-devil-is-in-the-details-wasp-18b monthly 0.5 2018-11-18 https://images.squarespace-cdn.com/content/v1/582a1d1f46c3c4d32caf6827/1541459669484-F05DAA3F5C8H1R9XHTTK/wasp18btransitpolarized Research Blog - The Devil is in the Details: WASP 18b One thing we examine is whether we have evidence of the transit measured around new phase. Here the planet occults the limb of the star where the polarized light vectors are strongest, the directions of the vectors then don’t cancel out (aren’t symmetric) so you get a net polarization from the star. You’ll notice the data points in the last image are noisy around new phase, that’s because they’re much shorter (in duration). We don’t see evidence of the transit in the data, but through modelling find we are unlikely to. https://images.squarespace-cdn.com/content/v1/582a1d1f46c3c4d32caf6827/1541459201825-MWXCDP5MZ7OO05E6DFXN/wasp18bpolarimetry Research Blog - The Devil is in the Details: WASP 18b Our unbinned polarimetric measurements of the combined WASP 18 system (star and planet). At 0 and 1 the planet is between you and the star (new phase); at 0.5 on the x-axis the planet is on the far side (in this case behind the star, full phase). The red lines are the best fit for a hot Jupiter that produced Rayleigh scattering in optimised conditions. The top panel and bottom panel are just Stokes vectors— that tells us about the particular direction of the polarization (so comparing them we could tell what the orbit of an unknown planet was… if it fit a red line…). https://images.squarespace-cdn.com/content/v1/582a1d1f46c3c4d32caf6827/1541458593303-NEB327EPNLTHPZ6Q2D3I/Screenshot+2018-11-05+14.46.23.png Research Blog - The Devil is in the Details: WASP 18b Right column: The tides imparted on WASP 18 by the orbiting hot Jupiter WASP 18b. In the lower panel the polarization vectors are shown. In the left column this effect is shown for the extreme case of a star reaching its Roche lobe (See our paper described in Soft Around the Edges) https://images.squarespace-cdn.com/content/v1/582a1d1f46c3c4d32caf6827/1541459940994-9T48S8VQ67OZ2O4U4U9S/wasp18bpolarizedatmospheres Research Blog - The Devil is in the Details: WASP 18b Using non-polarized observations of the system that were fit to atmospheric retrieval models, we create forward polarized light models for different cloud scenarios which might be present on the planet. The top panel is the relative flux, telling you in part how good each planet cloud scenario is at reflecting light; the middle panel is the polarization, telling you how good each cloud scenario is at polarizing light; the bottom panel is the main event: the polarized light signal for the system, or how much polarized light you could measure compared to how much light you get from the system (in parts-per-million, the best polarimeters can measure down to a couple ppm). The optically thick Rayleigh cloud is the strongest signal, and since we don’t see that strong a signal (60 ppm) in our measurements, we can probably rule out this scenario for the planet. https://www.kimbott.com/blog/2018/7/17/earths-next-top-model monthly 0.5 2018-11-13 https://images.squarespace-cdn.com/content/v1/582a1d1f46c3c4d32caf6827/1531862184149-1DWLBANCW22WPQY07H36/BaileyHD189733benstatite.png Research Blog - Earth's Next Top Model Examples of different particle sizes in Enstatite clouds for Permadeath (HD 189733b) in the expected unpolarized signal (top panel), polarization efficiency of the planet (middle panel) and actual polarized light signal (bottom panel). https://images.squarespace-cdn.com/content/v1/582a1d1f46c3c4d32caf6827/1531854392165-JTRBW23F2ORJGCCYG0KT/transitcloudfitsHD189733bPermadeath.png Research Blog - Earth's Next Top Model As previous literature suggested clouds of MgSiO3 (enstatite) or Mg2SiO4 (forsterite--a form of the olivine on Green Sands Beach, Hawaii) were good fits to the data. And with clouds and haze fitted in opacity and height one could fit most of this transmission spectrum and the dayside emissions. https://images.squarespace-cdn.com/content/v1/582a1d1f46c3c4d32caf6827/1531939529829-O8Y6ME6FYJRGIYG3BZ5N/vstaroutputVenusmap.png Research Blog - Earth's Next Top Model An example of the mapped polarized light output from a VSTAR model for Venus. The orange represents the reflectivity while the blue dashes show the intensity and direction of the polarized light. https://www.kimbott.com/blog/2017/8/29/dj9l2rwsij9nazuf4o0y9a9e1u8k0g monthly 0.5 2017-09-19 https://images.squarespace-cdn.com/content/v1/582a1d1f46c3c4d32caf6827/1504029906386-1TDP6HNVMATG2B0RRECX/stokes.png Research Blog - Soft Around the Edges Stokes parameters. Stokes Q and U are used to measure polarised light. Because they are vector, not just scalar quantities they encode information about the orientation of the objects polarising the light. https://images.squarespace-cdn.com/content/v1/582a1d1f46c3c4d32caf6827/1504030514648-NY4BF369A1G5KX76EX1K/Screenshot+2017-08-29+11.13.42.png Research Blog - Soft Around the Edges Models (VSTAR): The top panel here shows a model of the gravitational darkening for Regulus. The lower two panels show the polarisation vectors overlaid onto the surface. Note the polarisation is stronger for the bluer (400nm) wavelengths because this is driven by Rayleigh scattering. In redder (700 nm) light we see a strong signal in negative Stokes Q. https://images.squarespace-cdn.com/content/v1/582a1d1f46c3c4d32caf6827/1504030479801-CHBYCBNCJZ5JV1DC3W2U/Screenshot+2017-08-29+11.13.17.png Research Blog - Soft Around the Edges Observations: Positive values of U with negative values of Q give way to negative values of U and positive values of Q as we move towards shorter (bluer) wavelengths. The gray points are averaged over observations. The red points are corrected for interstellar polarisation. The blue line is the fitted orientation axis from this adjusted data. The green dashed lines show the bounds of the orientation axis from previous interferometric measurements. https://images.squarespace-cdn.com/content/v1/582a1d1f46c3c4d32caf6827/1504030050052-6RPKWL393KWUC6LMRE63/limbdarkeningstellarsolargravity.jpg Research Blog - Soft Around the Edges Our star, the Sun with star spots and Venus passing through its darkened limb. https://images.squarespace-cdn.com/content/v1/582a1d1f46c3c4d32caf6827/1504029824351-7Y1C54ZF3ZIUP8ZGMM67/limb_polarisation.jpg Research Blog - Soft Around the Edges On a symmetric star with an unobscured limb, no star spots, no planets moving through the limb, and no gravitational distortion those Stokes parameters cancel each other out. Equal values of positive Q to negative Q equal zero, and so on. https://www.kimbott.com/blog/2016/12/21/the-blue-skies-of-permadeath monthly 0.5 2018-11-13 https://images.squarespace-cdn.com/content/v1/582a1d1f46c3c4d32caf6827/1482352325312-X7JI4PZJXY6ZE4VG08U2/image-asset.png Research Blog - The Blue Skies of Permadeath The (binned) variation we observed, with a least squares fit Rayleigh scattering curve in red, compared the the curve fit to Berdyugina et al.'s data in blue. The offset from zero would be predominantly due to the interstellar polarisation from the ISM. Q/I and U/I are the normalised Stokes parameters, so their variation in relation to each other tells us about the planet's orbital orientation. https://images.squarespace-cdn.com/content/v1/582a1d1f46c3c4d32caf6827/1482352905374-BZ6CMWUQD03U4XPVO5CW/image-asset.jpeg Research Blog - The Blue Skies of Permadeath Net starlight is usually unpolarised, and a planet can polarise the light as it scatters off an ocean or through the atmosphere via Rayleigh scattering or rainbow effects. https://images.squarespace-cdn.com/content/v1/582a1d1f46c3c4d32caf6827/1482352647256-6SHZLQ9072CLZDXJGON9/image-asset.png Research Blog - The Blue Skies of Permadeath Examples of the polarised light signal from exoplanets with various orbital parameters (right) compared to the variation in albedo (left) from Seager et al. 2000. Rayleigh scattering maxes out when the star-planet-Earth are at 90 degrees, the polarised light curve (shown) has the shape of the sum of the Rayleigh curve and the albedo; the extrema of a transiting planet thus are at +/- 70 degrees from the secondary eclipse (here 0 is SE). https://images.squarespace-cdn.com/content/v1/582a1d1f46c3c4d32caf6827/1482352421332-SOGWAO7PXXZ3RLG7JSMT/image-asset.png Research Blog - The Blue Skies of Permadeath Berdyugina et al. 2011 saw more variation in polarised light through the orbit of the planet in blue light, corresponding to a much higher albedo in blue. This was confirmed by Evans et al. 2013 but for values corresponding to much lower polarisation. https://www.kimbott.com/blog/2016/12/21/another-hippi-paper-southern-bright-stars monthly 0.5 2018-11-13 https://images.squarespace-cdn.com/content/v1/582a1d1f46c3c4d32caf6827/1482350160330-79J73GRTNFN0HKQR0RZ0/image-asset.png Research Blog - Another HIPPI paper: Southern Bright Stars HIPPI's southern hemisphere survey results are in green; PlanetPol's northern hemisphere survey results in red. The positions are in galactic coordinantes, the darkness of the spot shows the distance, the size of the bars show the amount of polarisation. https://www.kimbott.com/blog/2016/12/21/thesis-submitted monthly 0.5 2016-12-21 https://images.squarespace-cdn.com/content/v1/582a1d1f46c3c4d32caf6827/1482349670672-X4TXV651KEN55NY77NOQ/image-asset.gif Research Blog - Thesis Submitted https://www.kimbott.com/blog/2016/12/2/the-hippi-polarimeter monthly 0.5 2016-12-21 https://images.squarespace-cdn.com/content/v1/582a1d1f46c3c4d32caf6827/1480716324733-DA3LP29SXEH363LIMOSN/image-asset.jpeg Research Blog - The HiPPI Polarimeter (Most of) the HIPPI team observing at the AAT in 2014. Credit: J.Bailey https://images.squarespace-cdn.com/content/v1/582a1d1f46c3c4d32caf6827/1480716522427-JGOE5ERBQUUCTLTM1LD2/image-asset.png Research Blog - The HiPPI Polarimeter The angle at which a rainbow forms changes depending on the type of molecule forming a droplet because the index of refraction will change. Credit: Wiki https://images.squarespace-cdn.com/content/v1/582a1d1f46c3c4d32caf6827/1480716960678-5Z8ORU8FJMS8YVWYO3O9/image-asset.png Research Blog - The HiPPI Polarimeter Prior to the photometric albedo measurements by Evans et al 2013, Berdyugina et al 2011 had polarimetric evidence that the exoplanet HD 189733b would appear blue in colour. Credit: Berdyugina et al 2011. https://images.squarespace-cdn.com/content/v1/582a1d1f46c3c4d32caf6827/1480716806318-SXGQHQJ8Z7WSV4S7NZB0/image-asset.jpeg Research Blog - The HiPPI Polarimeter Small but effective-- testing HIPPI in the lab. HIPPI uses carefully selected commercially available and 3-D printer components which helps drive the cost down while maintaining quality. Credit: J. Bailey https://www.kimbott.com/blog/tag/gas+giant monthly 0.5 https://www.kimbott.com/blog/tag/HD+189733b monthly 0.5 https://www.kimbott.com/blog/tag/polarimetry monthly 0.5 https://www.kimbott.com/blog/tag/hot+Jupiter monthly 0.5 https://www.kimbott.com/blog/tag/instrumentation monthly 0.5 https://www.kimbott.com/blog/tag/HiPPI monthly 0.5 https://www.kimbott.com/vstar daily 0.75 2023-12-01 https://images.squarespace-cdn.com/content/v1/582a1d1f46c3c4d32caf6827/1615259312276-DNPGTFK47FQR0QIA8SMK/EarthasExoIntQvsAveQ.png vstar If you are using our phase curve code, please note that it calculates the total signal from the planet in two ways: averaging the signal or integrating the signal. In cases without defined features like glint or strong limb polarization these values are similar (as above where the signal is dominated by Rayleigh scattering). The pfpfs and ipfpfs values in the code it should also be noted are already converted to a parts-per-million value (so here the signal is around 1e-12) and is a value for the total signal from the system (note this is not for Earth around the Sun, this is just an example plot). In other words for every 1e-12 from the system detected, approximately one will be polarized (from the planet’s Rayleigh scattering). The direct output from VSTAR itself of course is a grid across the surface of the planet and not in a total-signal phase curve form. https://images.squarespace-cdn.com/content/v1/582a1d1f46c3c4d32caf6827/1555630370564-X6YK1S9O0ESXM9NPHNSG/blackhole.jpg vstar https://images.squarespace-cdn.com/content/v1/582a1d1f46c3c4d32caf6827/1556218054790-T4YP6FDW504NFE75BDHQ/image-asset.jpeg vstar https://images.squarespace-cdn.com/content/v1/582a1d1f46c3c4d32caf6827/1556218677747-ITMWETUUO3GUU15AA6J7/image-asset.jpeg vstar https://www.kimbott.com/outreachteach daily 0.75 2024-02-08 https://images.squarespace-cdn.com/content/v1/582a1d1f46c3c4d32caf6827/1569013024763-9IF3A3PZSKFUITN1RMMM/KimBottmeAoTtalk.jpg Outreach & Teaching Speaking at Peddler Brewing Company for AoT https://images.squarespace-cdn.com/content/v1/582a1d1f46c3c4d32caf6827/1569013659698-32TEJ790AORFTO9UB27H/image-asset.jpeg Outreach & Teaching This is just a stock photo… giving me flashbacks… https://images.squarespace-cdn.com/content/v1/582a1d1f46c3c4d32caf6827/1569014106079-ERGC5YZQ59NQVHB0O3R2/Screenshot+2019-09-20+14.12.23.png Outreach & Teaching Scale of the Solar System planets radii and distances (each relative, radius is not on the same scale as distance) https://images.squarespace-cdn.com/content/v1/582a1d1f46c3c4d32caf6827/1560473098609-UBMWXEUJWJQXWESHDNUD/image-asset.jpeg Outreach & Teaching https://images.squarespace-cdn.com/content/v1/582a1d1f46c3c4d32caf6827/1569016313323-Y1WO5X2Q0WB7M286TEZT/microbialmat.001.jpg Outreach & Teaching https://images.squarespace-cdn.com/content/v1/582a1d1f46c3c4d32caf6827/1569017580412-NXTKUYKMAMEB0R2P6LJR/mekimteachinglecture.jpeg Outreach & Teaching https://www.kimbott.com/whatispolarimetry daily 0.75 2022-11-12 https://images.squarespace-cdn.com/content/v1/582a1d1f46c3c4d32caf6827/1560473160493-ZFJL1R56IIIIM6EUXCJU/image-asset.jpeg What is Polarimetry? https://images.squarespace-cdn.com/content/v1/582a1d1f46c3c4d32caf6827/1588972143697-0O5PKNC0FV2PKWCMZ8S2/LucynaMeHIPPIAAT.jpg What is Polarimetry? https://images.squarespace-cdn.com/content/v1/582a1d1f46c3c4d32caf6827/1588972338227-D4J8KWY8XAH8L3PIKAGP/jupiterQpolarization.png What is Polarimetry? https://www.kimbott.com/about daily 0.75 2024-03-26 https://images.squarespace-cdn.com/content/v1/582a1d1f46c3c4d32caf6827/1668284343882-7LB9BETMPSIEQBL27EJ7/neaurobio.jpeg About https://images.squarespace-cdn.com/content/v1/582a1d1f46c3c4d32caf6827/1668284343711-N2GYKAGN16VH92G94EP9/entropyandinfo.jpeg About https://images.squarespace-cdn.com/content/v1/582a1d1f46c3c4d32caf6827/1668284344577-10LFZKD86N39HXSC6698/thesparrow.jpeg About https://images.squarespace-cdn.com/content/v1/582a1d1f46c3c4d32caf6827/1668284345194-E11BP4ORARFEJAXT5M9J/brilliantabyss.jpeg About https://images.squarespace-cdn.com/content/v1/582a1d1f46c3c4d32caf6827/1668284345643-YAYE5TNN9YR3KC2CNLUG/islamscifi.jpeg About https://images.squarespace-cdn.com/content/v1/582a1d1f46c3c4d32caf6827/1709170397291-AHFDTJLWLUOE4HKSNJ95/visiblelearningforteacherscover.jpeg About https://images.squarespace-cdn.com/content/v1/582a1d1f46c3c4d32caf6827/1479165737752-CHCBEGD273LB2J7KT1VM/image-asset.jpeg About Fishing in the Salish Sea, where I grew up. https://images.squarespace-cdn.com/content/v1/582a1d1f46c3c4d32caf6827/1668283287154-87YWD2CIWZYD46CYLYC2/annihilation.jpeg About https://images.squarespace-cdn.com/content/v1/582a1d1f46c3c4d32caf6827/1668283287157-TWPR2XSVXYGZDDL454KA/merchantsofdoubt.jpeg About https://images.squarespace-cdn.com/content/v1/582a1d1f46c3c4d32caf6827/1668283287923-PNKE63OFEQNYJ1PVQNZL/homewaters.jpeg About https://images.squarespace-cdn.com/content/v1/582a1d1f46c3c4d32caf6827/1668283288143-T7T6M5YTD3RW0CUO6LDE/storiesofyourlife.jpeg About https://images.squarespace-cdn.com/content/v1/582a1d1f46c3c4d32caf6827/1668283288917-FCH61I58KTE009Y528WQ/LightColorOutdoors.jpeg About https://images.squarespace-cdn.com/content/v1/582a1d1f46c3c4d32caf6827/1709228112121-YJCULC9VDJBFFBY0NBHF/contactOGcover.jpeg About https://www.kimbott.com/pagecv daily 0.75 2024-01-04 https://www.kimbott.com/publications daily 0.75 2023-10-16 https://www.kimbott.com/eiob2-poster-audio-narration daily 0.75 2022-11-01 https://www.kimbott.com/polarization-gifs daily 0.75 2022-11-01 https://images.squarespace-cdn.com/content/v1/582a1d1f46c3c4d32caf6827/89b8b29a-b562-46a3-8707-5c0a028bd8cb/V_600umSV.gif Polarization gifs - Make it stand out Whatever it is, the way you tell your story online can make all the difference. https://images.squarespace-cdn.com/content/v1/582a1d1f46c3c4d32caf6827/424e4646-f995-417b-8566-bf8dc74597a2/inttestEarthcloudyocean1000nm.gif Polarization gifs - Make it stand out Whatever it is, the way you tell your story online can make all the difference. https://www.kimbott.com/3d-model-animations daily 0.75 2022-11-01