UP 8799 popping out from behind a tree as long eastbound pusher on autorack duty... maybe... because most of the consist remains hidden behind the hills and across the unused lanes that were supposed to be eastbound, but due to budget cuts, Nebraska, like Wyoming, has chosen to close large stretches of interstate and tear them up under the ...

2 天之前 · NASA’s James Webb Space Telescope has captured direct images of multiple gas giant planets within an iconic planetary system. HR 8799, a young system 130 light-years away, has long been a key target for planet formation studies. The observations indicate that the well-studied planets of HR 8799 are rich in carbon dioxide gas.

HR 8799 is a roughly 30 million-year-old main-sequence star located 133.3 light-years (40.9 parsecs) away from Earth in the constellation of Pegasus. It has roughly 1.5 times the Sun 's mass and 4.9 times its luminosity. It is part of a system that also contains a debris disk and at least four massive planets.

2 天之前 · HR 8799, a young system 130 light-years away, has long been a key target for planet formation studies. ... “We have other lines of evidence that hint at these four HR 8799 planets forming using this bottom-up approach,” said Laurent Pueyo, an astronomer at the Space Telescope Science Institute in Baltimore, who co-led the work.

2 天之前 · First, the HR 8799 planets are offset toward bluer F430M – F410M colors than the field BDs by about half a magnitude. Second, despite their relatively similar NIR colors, the HR 8799 planets are dramatically spread (by up to a magnitude) in their 3–5 μm colors. Third, the HR 8799 planets follow an apparent radial sequence in F460M ...

1 天前 · The newly detected carbon dioxide in one of the planets, HR 8799 e, shows there is a significant amount of heavy metals in the planet's atmosphere, which aligns with the leading, "bottom up ...

HR 8799 e is the fourth planet orbiting HR 8799 in order of discovery. It is a young, hot and massive gas giant, and is fairly close to its star, lying just between the orbits of Saturn and Uranus in the Solar System. The planet is still glowing red-hot. [1]HR 8799 e is the innermost known planet as it orbits closer to its star than the other three known planets in this planetary system.

2024年10月24日 · HR 8799 c is a gas giant exoplanet that orbits a F-type star. Its mass is 10 Jupiters, it takes 189 years to complete one orbit of its star, and is 38 AU from its star. Its discovery was announced in 2008.

2011年10月6日 · This is an illustration of the HR 8799 exoplanet system based on the reanalysis of Hubble NICMOS data and ground-based observations. The positions of the star and the orbits of the four known planets are shown schematically.

12 小时之前 · La CO 2 su Hr 8799 "Rilevando queste grandi formazioni di anidride carbonica, abbiamo dimostrato che nelle atmosfere di questi pianeti è presente una frazione considerevole di elementi più ...