Optical To Near-infrared Transit Observations Of Super-Earth GJ1214b: Water-world Or Mini-Neptune?

Details Optical To Near-infrared Transit Observations Of Super-Earth GJ1214b: Water-world Or Mini-Neptune? Optical To Near-infrared Transit Observations Of Super-Earth GJ1214b: Water-world Or Mini-Neptune?

Sep 2011

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2011ess.....2.4009b&link_type=abstract

American Astronomical Society, ESS meeting #2, #40.09

Astronomy and Astrophysics

Astronomy

Scientific paper

In late 2009, the discovery of the transiting 6.5 Earth-mass planet GJ1214b was announced by the MEarth team. With a mean density 35% of that of the Earth, this planet could either be a ''mini-Neptune'', consisting of a rocky core and a thick, hydrogen-dominated atmosphere, or a water-dominated planet: in the first case, the large atmospheric scale-height may result in a detectable transmission spectrum.
We obtained ground-based observations during several transits of GJ1214b, using a range of instruments and photometric filters, and spanning from the visible to the near-infrared. By comparing the transit depth between these bands, we investigated the properties of the atmosphere.
The resulting transmission spectrum is essentially flat, except for a 2 sigma positive deviation in g-band and a lower increase in Ks-band. Our data are globally consistent with the water-world scenario, although a model with a hydrogen atmosphere of sub-solar metallicity and a cloud deck - suppressing most of the spectral features - seems to be in better agreement with our measurements.
When including results from different authors, this intermediate model fits even better the transmission spectrum of GJ1214b. We recently observed two additional transits of the planet in Kc- and g-band, in order to better assess the significance of the deviation from a flat transmission spectrum.
We finally show that a variable spot level on the surface of the parent star can significantly alter not only the average value of the transit depth, but also the slope of the transmission spectrum.

Affiliated with

Also associated with

No associations

Rating

Optical To Near-infrared Transit Observations Of Super-Earth GJ1214b: Water-world Or Mini-Neptune? does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Optical To Near-infrared Transit Observations Of Super-Earth GJ1214b: Water-world Or Mini-Neptune?, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Optical To Near-infrared Transit Observations Of Super-Earth GJ1214b: Water-world Or Mini-Neptune? will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-833196