The ultrahot Jupiter KELT-9b has an equilibrium temperature of approximately 4000 K and exhibits absorption by several metal species in its transmission spectrum. In this study, the authors used the CARMENES spectrograph to observe partial phase curves and search for atomic and molecular lines in its emission spectrum. They found evidence for emission by Si I, Fe I, Mg I and Ca II in the atmosphere of KELT-9b. However, they did not find any evidence for dayside emission from other species such as Al I, Ca I, Cr I, FeH, Fe II, K I, Li I, Mg II, Na I , OH , Ti I , TiO , V I , V II VO or YI. By employing likelihood mapping techniques on their data analysis results from cross-correlation methods used to search atmospheric species with model spectra and corrected spectra after reducing data and correcting telluric lines and systematics; they found indications of there being little variation in emission line contrast between the day- and nightsides. This suggests that KELT-9b may harbor iron emission on its nightside. The authors also generated continuum-subtracted model emission spectra using petitRADTRANS software to fit a polynomial to the continuum and subtract it from the model spectra. They used pressure-temperature profiles from Goyal et al., which are only defined for pressures greater than 10^-6 bar to create these model spectra. Their findings demonstrate that high-resolution ground-based emission spectroscopy can provide valuable insights into exoplanet atmospheres such as those observed in KELT-9b's atmosphere. The detailed data processing steps used in this analysis are shown through Figure 3 while Figure 4 shows pressure-temperature profiles used to create model emission spectra of KELT-9b. These findings have been accepted for publication in AJ journal.
- Ultrahot Jupiter KELT-9b has an equilibrium temperature of approximately 4000 K and exhibits absorption by several metal species in its transmission spectrum.
- The authors used the CARMENES spectrograph to observe partial phase curves and search for atomic and molecular lines in its emission spectrum.
- Evidence was found for emission by Si I, Fe I, Mg I and Ca II in the atmosphere of KELT-9b, but not for other species such as Al I, Ca I, Cr I, FeH, Fe II, K I, Li I, Mg II, Na I , OH , Ti I , TiO , V I , V II VO or YI.
- Likelihood mapping techniques were employed on their data analysis results from cross-correlation methods used to search atmospheric species with model spectra and corrected spectra after reducing data and correcting telluric lines and systematics.
- Little variation in emission line contrast between the day- and nightsides suggests that KELT-9b may harbor iron emission on its nightside.
- High-resolution ground-based emission spectroscopy can provide valuable insights into exoplanet atmospheres such as those observed in KELT-9b's atmosphere.
- Continuum-subtracted model emission spectra were generated using petitRADTRANS software to fit a polynomial to the continuum and subtract it from the model spectra.
- Pressure-temperature profiles from Goyal et al., which are only defined for pressures greater than 10^-6 bar were used to create these model spectra.
- Detailed data processing steps used in this analysis are shown through Figure 3 while Figure 4 shows pressure-temperature profiles used to create model emission spectra of KELT-9b.
- These findings have been accepted for publication in AJ journal.
Scientists studied a very hot planet called KELT-9b and found that it has a temperature of about 4000 degrees Celsius. They used a special tool called CARMENES to look at the planet's atmosphere and found evidence of certain metals like silicon, iron, magnesium, and calcium. They didn't find other types of metals or molecules in the atmosphere. The scientists used different methods to analyze their data and create models of what the planet's atmosphere might be like. They also used software called petitRADTRANS to help them understand the data better. These findings will be published in a scientific journal called AJ.
Definitions
- Ultrahot Jupiter: A type of exoplanet that is similar in size to Jupiter but orbits very close to its star, making it extremely hot.
- Equilibrium temperature: The temperature that a planet would have if it were not heated by any internal or external sources.
- Spectrograph: An instrument that separates light into its different colors (or wavelengths) so scientists can study it.
- Emission spectrum: The pattern of colors emitted by an object when it is heated or excited in some way.
- Model spectra: Predictions made by scientists about what the spectrum of an object should look like based on certain assumptions or theories.
- Telluric lines: Absorption lines caused by Earth's atmosphere that can interfere with observations of celestial objects.
- Systematics: Errors or biases in data caused by factors such as instrument calibration, atmospheric conditions, or
Exploring the Atmosphere of KELT-9b: A Hot Jupiter with an Ultrahigh Temperature
KELT-9b is a hot Jupiter exoplanet located about 640 light years away from Earth. It has an equilibrium temperature of approximately 4000 K and exhibits absorption by several metal species in its transmission spectrum. In this study, the authors used the CARMENES spectrograph to observe partial phase curves and search for atomic and molecular lines in its emission spectrum. The findings were accepted for publication in AJ journal.
Background Information on KELT-9b
KELT-9b orbits a star known as HD 195689 which is about 2.8 times more massive than our Sun and has a surface temperature of 8500 K, making it one of the hottest stars known to date. This makes KELT-9b one of the most extreme planets ever discovered, with temperatures reaching up to 4000K during its day side due to its close proximity to its host star (about 0.03 AU). Its atmosphere is also composed mostly of hydrogen gas with traces of metals such as iron, magnesium, silicon, calcium and titanium present in small amounts.
The Study
In this study, the authors used data collected from CARMENES spectrograph at Calar Alto Observatory (Spain) over two nights between July 2018 - August 2019 to observe partial phase curves and search for atomic/molecular lines in KELT-9b's emission spectrum. They found evidence for emission by Si I, Fe I, Mg I and Ca II but did not find any evidence for dayside emission from other species such as Al I , Ca I , Cr I , FeH , Fe II , KI , LiI , MgII , NaI OH TiI TiO Vl Vll VO or Yl .
To further analyze their results they employed likelihood mapping techniques on their data analysis results from cross correlation methods used to search atmospheric species with model spectra and corrected spectra after reducing data correcting telluric lines systematics etc.. This led them to conclude that there was little variation in emission line contrast between day side nightside suggesting that there may be iron emissions on Kelt 9bs nightside .
The authors then generated continuum subtracted model emission spectra using petitRADTRANS software which allowed them fit polynomial continua subtracting it from model spectra while using pressure temperature profiles defined only above 10^ 6 bar . Figure 3 shows detailed data processing steps while figure 4 shows pressure temperature profiles used create model emission spectra .
Conclusion
This study provides valuable insights into exoplanet atmospheres such as those observed in Kelt 9bs atmosphere through high resolution ground based observation techniques . It demonstrates how powerful tools like CARMENES can be when combined with sophisticated modelling techniques like petitRADTRANS allowing us explore distant worlds beyond our solar system providing new understanding into these mysterious objects orbiting far away stars .
