Brown dwarfs as candidates for detecting UV aurora outside the Solar System: Hubble Space Telescope observations of 2MASS J1237+6526

Characterisation of Transneptunian Binaries in the HST Archive.

10.5194/epsc2020-263 ◽

2020 ◽

Author(s):

Richard Smith ◽

Wesley Fraser ◽

Alan Fitzsimmons

Keyword(s):

Solar System ◽

Hubble Space Telescope ◽

Planetary Science ◽

Space Telescope ◽

Model Image ◽

Colour Measurements ◽

Fitting Algorithm ◽

Planetary Migration ◽

Image Position ◽

Parameter Values

Binary Transneptunian Objects (TNOs) have remained virtually unaltered since the formation of the solar system. They can therefore provide valuable insights into the history and properties of objects from the outer solar system, such as object compositions and dynamical history, including the effects of planetary migration on primordial planetesimal populations. Benecchi et al. 2009 measured the colours of 23 TNO binaries using the Hubble Space Telescope (HST), reporting a strong correlation between primary-secondary F606W-F814W colours. Marsset et al. 2020 extended this work into the NIR, adding a further three TNO binary objects with accurate colour measurements made using the Gemini-North telescope which indicated a similar colour correlation in the infrared.&#160;&#160; We aim to increase the number of binary TNOs with accurate NIR colour measurements by reprocessing data available in the HST archive using a consistent MCMC-based point spread function (PSF)-fitting algorithm. We explore both the position and brightness parameter space for the binary components. Tiny Tim (Krist et al., 2011) PSFs are generated for each component and planted in a model image that is compared with the HST archive image to identify best-fit PSF parameter values. These values are then used to produce and subtract a final model image, providing accurate likelihood estimates for the in-image position and photometric brightness of each component.&#160;&#160; We will present the results of applying the algorithm to archival data of 24 known binaries, including both optical and NIR colour measurements of both binary components. We will also provide a measure of our sensitivity to binary component separations and brightness ratios. Our results will be compared to the correlated colours observed by Benecchi et al. (2009) and Marsset et al. (2020).&#160;References:S. D. Benecchi, K. S. Noll, W. M. Grundy, M. W. Buie, D. C. Stephens, andH. F. Levison. The correlated colors of transneptunian binaries. Icarus, 200(1):292&#8211;303, Mar 2009. doi: 10.1016/j.icarus.2008.10.025.J Krist, R Hook, and F Stoehr. 20 years of hubble space telescope opticalmodeling using tiny tim, 2011. URLhttps://doi.org/10.1117/12.892762.Micha &#776;el Marsset, Wesley C. Fraser, Michele T. Bannister, Megan E. Schwamb, Rosemary E. Pike, Susan Benecchi, J. J. Kavelaars, Mike Alexandersen, Ying-Tung Chen, Brett J. Gladman, Stephen D. J. Gwyn, Jean-Marc Petit, and Kathryn Volk. Col-OSSOS: Compositional Homogeneity of Three KuiperBelt Binaries.The Planetary Science Journal, 1(1):16, June 2020. doi:10.3847/PSJ/ab8cc0.

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Evidence for a large exomoon orbiting Kepler-1625b

Science Advances ◽

10.1126/sciadv.aav1784 ◽

2018 ◽

Vol 4 (10) ◽

pp. eaav1784 ◽

Cited By ~ 56

Author(s):

Alex Teachey ◽

David M. Kipping

Keyword(s):

Solar System ◽

Hubble Space Telescope ◽

The Moon ◽

Space Telescope ◽

Model Predictions ◽

Self Consistent ◽

Natural Satellites

Exomoons are the natural satellites of planets orbiting stars outside our solar system, of which there are currently no confirmed examples. We present new observations of a candidate exomoon associated with Kepler-1625b using the Hubble Space Telescope to validate or refute the moon’s presence. We find evidence in favor of the moon hypothesis, based on timing deviations and a flux decrement from the star consistent with a large transiting exomoon. Self-consistent photodynamical modeling suggests that the planet is likely several Jupiter masses, while the exomoon has a mass and radius similar to Neptune. Since our inference is dominated by a single but highly precise Hubble epoch, we advocate for future monitoring of the system to check model predictions and confirm repetition of the moon-like signal.

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Cloud Atlas: Hubble Space Telescope Near-infrared Spectral Library of Brown Dwarfs, Planetary-mass Companions, and Hot Jupiters

The Astronomical Journal ◽

10.3847/1538-3881/aaf88f ◽

2019 ◽

Vol 157 (3) ◽

pp. 101 ◽

Cited By ~ 10

Author(s):

Elena Manjavacas ◽

Dániel Apai ◽

Yifan Zhou ◽

Ben W. P. Lew ◽

Glenn Schneider ◽

...

Keyword(s):

Near Infrared ◽

Hubble Space Telescope ◽

Brown Dwarfs ◽

Spectral Library ◽

Space Telescope ◽

Hot Jupiters ◽

Planetary Mass ◽

Infrared Spectral ◽

Cloud Atlas

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The Gaia spectrophotometric standard stars survey – V. Preliminary flux tables for the calibration of Gaia DR2 and (E)DR3

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/stab766 ◽

2021 ◽

Vol 503 (3) ◽

pp. 3660-3676

Author(s):

E Pancino ◽

N Sanna ◽

G Altavilla ◽

S Marinoni ◽

M Rainer ◽

...

Keyword(s):

Hubble Space Telescope ◽

Brown Dwarfs ◽

Space Telescope ◽

B Stars ◽

Reference Scale ◽

Systematic Effects ◽

M Stars ◽

Gaia Dr2 ◽

Stars Survey ◽

Better Than

ABSTRACT We present the flux tables of the spectrophotometric standard stars (SPSS) used to calibrate in flux the Gaia DR2 and (E)DR3 data releases. The latest SPSS grid version contains 112 stars, whose flux tables agree to better than 1 per cent with the CALSPEC spectra of 11 flux standards for the calibration of the Hubble Space Telescope. The synthetic magnitudes computed on the SPSS spectra also agree to better than 1 per cent with the Landolt magnitudes of 37 stars in common. The typical spreads in both comparisons are of the order of 1 per cent. These uncertainties already meet the initial requirements for the Gaia SPSS project, but further improvements are expected in the next SPSS versions, that will be used to calibrate future Gaia releases. We complement the SPSS flux tables with literature spectra of 60 additional stars that did not pass all the criteria to be SPSS, the Passband Validation Library (PVL). The PVL contains stars of extreme spectral types, such as bright O and B stars and late M stars and brown dwarfs, and was useful to investigate systematic effects in the previous Gaia DR2 release and to minimize them in the EDR3 one. The PVL literature spectra are recalibrated as accurately as possible on to the SPSS reference scale, so that the two sets together can be used in a variety of validation and comparison studies.

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