HAT-P-26b: A Neptune-mass exoplanet with a well-constrained heavy element abundance.

Science 2017 05;356(6338):628-631

Astrophysics Group, University of Exeter, Physics Building, Stocker Road, Exeter, Devon, EX4 4QL UK.

A correlation between giant-planet mass and atmospheric heavy elemental abundance was first noted in the past century from observations of planets in our own Solar System and has served as a cornerstone of planet-formation theory. Using data from the Hubble and Spitzer Space Telescopes from 0.5 to 5 micrometers, we conducted a detailed atmospheric study of the transiting Neptune-mass exoplanet HAT-P-26b. We detected prominent HO absorption bands with a maximum base-to-peak amplitude of 525 parts per million in the transmission spectrum. Using the water abundance as a proxy for metallicity, we measured HAT-P-26b's atmospheric heavy element content ([Formula: see text] times solar). This likely indicates that HAT-P-26b's atmosphere is primordial and obtained its gaseous envelope late in its disk lifetime, with little contamination from metal-rich planetesimals.

Download full-text PDF

Source
http://dx.doi.org/10.1126/science.aah4668DOI Listing
May 2017

Publication Analysis

Top Keywords

heavy element
8
neptune-mass exoplanet
8
atmospheric heavy
8
water abundance
4
base-to-peak amplitude
4
maximum base-to-peak
4
bands maximum
4
amplitude 525
4
525 parts
4
transmission spectrum
4
parts transmission
4
absorption bands
4
spectrum water
4
detected prominent
4
conducted detailed
4
micrometers conducted
4
telescopes micrometers
4
space telescopes
4
detailed atmospheric
4
atmospheric study
4

Similar Publications