Exoplanet WASP-96 b (NIRISS Transit Light Curve)

Stsci_2022-032b_1024

stsci_2022-032b July 12th, 2022

Credit: NASA, ESA, CSA, STScI, Webb ERO Production Team

A light curve from Webb’s Near-Infrared Imager and Slitless Spectrograph (NIRISS) shows the change in brightness of light from the WASP-96 star system over time as the planet transits the star. A transit occurs when an orbiting planet moves between the star and the telescope, blocking some of the light from the star. This observation was made using NIRISS’s Single-Object Slitless Spectroscopy (SOSS) mode, which involves capturing the spectrum of a single bright object, like the star WASP-96, in a field of view.

To capture these data, Webb stared at the WASP-96 star system for 6 hours 23 minutes, beginning about 2½ hours before the transit and ending about 1½ hours after the transit was complete. The transit itself lasted for just under 2½ hours. The curve includes a total of 280 individual brightness measurements – one every 1.4 minutes.

Because the observation was made using a spectrograph, which spreads the light out into hundreds of individual wavelengths, each of the 280 points on the graph represents the combined brightness of thousands of wavelengths of infrared light.

The actual dimming caused by the planet is extremely small: The difference between the brightest and dimmest points is less than 1.5 percent. NIRISS is ideally suited for this observation because it has the ability to observe relatively bright targets over time, along with the sensitivity needed to measure such small differences in brightness: In this observation, the instrument was able to measure differences in brightness as small as 0.02 percent.

Although the presence, size, mass, and orbit of the planet had already been determined based on previous transit observations, this transit light curve can be used to confirm and refine existing measurements, such as the planet’s diameter, the timing of the transit, and the planet’s orbital properties.

WASP-96 b is a hot gas giant exoplanet that orbits a Sun-like star roughly 1,150 light years away, in the constellation Phoenix. The planet orbits extremely close to its star (less than 1/20th the distance between Earth and the Sun) and completes one orbit in less than 3½ Earth-days. The planet’s discovery, from ground-based observations, was announced in 2014.

The background illustration of WASP-96 b and its Sun-like star is based on current understanding of the planet from both NIRISS spectroscopy and previous ground- and space-based observations. Webb has not captured a direct image of the planet or its atmosphere.

NIRISS was contributed by the Canadian Space Agency. The instrument was designed and built by Honeywell in collaboration with the Université de Montréal and the National Research Council Canada.

Provider: Space Telescope Science Institute

Image Source: https://webbtelescope.org/contents/news-releases/2022/news-2022-032

Curator: STScI, Baltimore, MD, USA

Image Use Policy: http://hubblesite.org/copyright/

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Image Details

Image Type
Chart
Object Name
WASP-96 b
Subject - Milky Way
Planet > Type > Gas Giant

Distance

Universescale1
1,161 light years

Position Details

Position (ICRS)
RA = 0h 4m 11.0s
DEC = -47° 21’ 38.2”
Constellation
Phoenix
Stsci_2022-032b_1280
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ID
2022-032b
Subject Category
B.1.1.2  
Subject Name
WASP-96 b
Credits
NASA, ESA, CSA, STScI, Webb ERO Production Team
Release Date
2022-07-12T00:00:00
Lightyears
1,161
Redshift
1,161
Reference Url
https://webbtelescope.org/contents/news-releases/2022/news-2022-032
Type
Chart
Image Quality
Good
Distance Notes
Facility
Instrument
Color Assignment
Band
Bandpass
Central Wavelength
Start Time
Integration Time
Dataset ID
Notes
Coordinate Frame
ICRS
Equinox
Reference Value
1.0458, -47.3606
Reference Dimension
Reference Pixel
Scale
Rotation
Coordinate System Projection:
Quality
Position
FITS Header
Notes
Creator (Curator)
STScI
URL
http://hubblesite.org
Name
Space Telescope Science Institute Office of Public Outreach
Email
outreach@stsci.edu
Telephone
410-338-4444
Address
3700 San Martin Drive
City
Baltimore
State/Province
MD
Postal Code
21218
Country
USA
Rights
http://hubblesite.org/copyright/
Publisher
STScI
Publisher ID
stsci
Resource ID
STScI-J-p22032b-f-16000x10763.tif
Metadata Date
2022-07-11T10:05:29-04:00
Metadata Version
1.2
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Detailed color mapping information coming soon...

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Universescalefull
1,161 light years