Astronomical

Kepler-452b (Artist Concept)

This artist's concept depicts one possible appearance of the planet Kepler-452b, the first near-Earth-size world to be found in the habitable zone of star that is similar to the Sun. The habitable zone is a region around a star where temperatures are right for water — an essential ingredient for life as we know it — to pool on the surface. Scientists do not know if Kepler-452b can support life or not.

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Astronomical

Solar Sibling HD 162826

The star HD 162826 is probably a "solar sibling," that is, a star born in the same star cluster as the Sun. It was identified by University of Texas at Austin astronomer Ivan Ramirez, in the process of honing a technique to find more solar siblings in the future, and eventually to determine how and where in the Milky Way galaxy the Sun formed.

HD 162826 is not visible to the unaided eye, but can be seen with low-power binoculars. It is 110 light-years away in the constellation Hercules, and appears not far from the bright star Vega in the night sky.

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Astronomical

Size of NGC 1277's Black Hole

This diagram shows how the diamater of the 17-billion-solar-mass black hole in the heart of galaxy NGC 1277 compares with the orbit of Neptune around the Sun. The black hole is eleven times wider than Neptune's orbit. Shown here in two dimensions, the "edge" of the black hole is actually a sphere. This boundary is called the "event horizon," the point from beyond which, once crossed, neither matter nor light can return.

Credit: D. Benningfield/K. Gebhardt/StarDate

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Astronomical

Environment of NGC 1277

The galaxy NGC 1277 (center) is embedded in the nearby Perseus galaxy cluster. All the ellipticals and round yellow galaxies in the picture are located in this cluster. NGC 1277 is a relatively compact galaxy compared to the galaxies around it. The Perseus cluster is 250 million light years from us.

Credit: David W. Hogg, Michael Blanton, and the SDSS Collaboration

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Astronomical

CANDELS galaxy colors

The red circles from left to right represent the measured average color of galaxies at a redshift of 4, 5, 6 and 7, where the bottom axis shows the time since the Big Bang. The light blue bar running through the center of the diagram shows the color of the local galaxy NGC 1705, which contains no dust. When CANDELS astronomers saw that the redshift 7 galaxies in their sample have a similar color as NGC 1705, they derived that those are also dust free. The gradual reddening they observed at lower and lower redshifts reveals that the galaxies are getting dustier with time.

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Astronomical

CANDELS galaxies

A small portion of one of the CANDELS fields; small circles indicate galaxies included in the survey. Galaxies seen at various distances are circled in colors according to epoch. Galaxies at a redshift of 4, or 1.5 billion years after the Big Bang, are circled in magenta, while galaxies at 5, 6, 7 and 8 are circled in blue, green, yellow and red, respectively. The three insets show a zoomed in view of three galaxies; the upper-left panel is one at a redshift of 4, the lower-right is at a redshift of 6, and the lower-left is at a redshift of 7.

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Astronomical

Evidence for Gravitational Waves

Data showing the decreasing orbital period of J0651. The dotted lines shows when the eclipse times should occur if the orbit were constant. The top panel shows how the eclipses have changed from when expected; the dashed line fits the observations. The bottom panel shows a zoomed view of the primary eclipses for four different months of observations (the colors correspond to the points in the top panel). Over time, the mid-point of the eclipses happen sooner (they shift to the left), indicating that the orbital period of the binary system is shrinking.

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Astronomical

Major Merger

This Hubble image of NGC 4676, nickednamed “The Mice,” illustrates an ongoing major merger between two colliding galaxies of similar mass. The gravitational forces between the two galaxies have produced two long tails of gas and stars stretching away from the galaxies, as well as a bridge of stripped material between the galaxies. Credit: NASA, H. Ford (JHU), G. Illingworth (UCSC/LO), M.Clampin (STScI), G. Hartig (STScI), the ACS Science Team, and ESA

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Comparison of Massive Galaxies at Early Times vs. Today

Massive galaxies today are substantially larger and more bulgy than massive galaxies 10 billion years ago. The left column illustrates the difference in size by comparing a face-on view of the massive present-day elliptical galaxy (NGC 4472) to the Hubble NICMOS image of a face-on ultra-compact galaxy from 10 billion years ago. The right column highlights the disky nature of massive young galaxies by contrasting an edge-on view of a modern bulge-dominated spiral (NGC 4594, the Sombrero Galaxy) with the an edge-on view of a massive disky galaxy from 10 billion years ago. Credit: T.

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Astronomical

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