Interactive Overview
Slider Interactive: A series of images showing the same patch of sky containing four planets orbiting a young star over time. Below the caption is a horizontal slider bar with six labeled stops and a solid white circle. Dragging the white circle right and left along the slider bar causes elements of the image, labels, and caption to change. The change occurs gradually as one image, along with its associated caption and labels, fades out and the next fades in. A toggle button to the upper right of the image turns the image labels on and off. Some labels are in the form of text with arrows pointing to specific features in the image. Other labels are graphic overlays.
Slider Stops
From left to right, the slider stops are labeled: 8/01/2009, 7/21/2010, 7/20/2011, 10/26/2012, 10/15/2013, and 7/17/2014.
Summary of Slider Stops
Sliding left to right reveals the following:
- “8/01/2009” stop shows four small, bright blue-white dots surrounding a black circle in the center. This is the initial image shown when the interactive is loaded.
- “7/21/2010” stop shows the same four small, blue-white dots surrounding a black circle in the center. The points of light are slightly dimmer and their positions have slightly shifted counterclockwise around the black circle.
- “7/20/2011” stop shows the same four small, blue-white dots surrounding a black circle in the center. The points of light are slightly smaller and their positions have slightly shifted counterclockwise around the black circle.
- “10/26/2012” stop shows the same four small, blue-white dots surrounding a black circle in the center. The points of light are slightly brighter and their positions have slightly shifted counterclockwise around the black circle.
- “10/15/2013” stop shows the same four small, blue-white dots surrounding a black circle in the center. The points of light are slightly brighter and larger, and their positions have slightly shifted counterclockwise around the black circle.
- “7/17/2014” stop shows the same four small, blue-white dots surrounding a black circle in the center. Their positions have slightly shifted counterclockwise around the black circle.
Stop 1: 8/01/2009
Image Description: 8/01/2009
Against a blue background is a black circle in the center with a small yellow star icon within it. Around the black circle are blotches of dark blue, light blue, and white that form a ring. The blotchy texture is more distinct closer to the black circle and gradually fades into the main blue background as distance from the black circle increases. Four small, bright blue-white points of light are scattered around the black circle and are located (starting clockwise) in the 1 o’clock, 4 o’clock, 5 o’clock, and 10 o’clock positions. The point at the 4 o’clock position is closest to the star. Moving radially outward in order of distance are the 5 o’clock point, the 1 o’clock point and the 10 o’clock point.
Labels: 8/01/2009
There are six text labels and four graphic overlays. The small yellow star icon in the center of the black circle is labeled “Blocked star.” Each of the four small blue-white points of light that are scattered around the black circle are highlighted by white rings, along with their planet names. Starting clockwise, the planets names are: HR 8799 c at 1 o’clock, HR 8799 e at 4 o’clock, HR 8799 d at 5 o’clock, and HR 8799 b at 10 o’clock. The first planet, HR 8799 c at 1 o’clock, has an additional text label that reads “Planet.”
Caption: 8/01/2009
When most of the bright light of HR 8799 is blocked by a coronagraph, it is possible to detect four planets.
Stop 2: 7/21/2010
Image Description: 7/21/2010
This image reveals the same patch of sky, now seen on 7/21/2010. The same four small blue-white dots, as seen in the prior stop, have shifted slightly counterclockwise. They still surround the black circle and are less bright. Also around the black circle, which has a small yellow star icon within it, are blotches of dark blue, light blue, and white that form a ring. The blotchy texture is more distinct closer to the black circle and gradually fades into the main blue background as distance from the black circle increases.
Labels: 7/21/2010
There are three text labels. The blue-white dot at 1 o’clock is labeled “Warmer, brighter planet.” At the center, a white thin smudge that traces a small portion of the black circle’s edge is labeled “Leftover starlight.” The faint blue-white dot at 10 o’clock is labeled “Cooler, dimmer planet.”
Caption: 7/21/2010
The Keck telescope in Hawaii detects heat radiated from the planets in the form of infrared light.
Stop 3: 7/20/2011
Image Description: 7/20/2011
This image reveals the same patch of sky, now seen on 7/20/2011. The same four small blue-white dots, as seen in the prior stop, have shifted slightly counterclockwise. They still surround the black circle and are smaller. Also around the black circle, which has a small yellow star icon within it, are blotches of dark blue, light blue, and white that form a ring thicker than in prior stops. The blotchy texture is more distinct closer to the black circle and gradually fades into the main blue background as distance from the black circle increases.
Labels: 7/20/2011
There are two text labels. The blue-white dot at 1 o’clock is labeled “Brighter, more massive planet,” while its counterpart toward 10 o’clock is labeled “Dimmer, less massive planet.”
Caption: 7/20/2011
The brightness of a planet in infrared can provide clues about its mass.
Stop 4: 10/26/2012
Image Description: 10/26/2012
This image reveals the same patch of sky, now seen on 10/26/2012. The same four small blue-white dots, as seen in the prior stop, have shifted slightly counterclockwise around the black circle. The closest planet has moved the most since the first stop, and is now between the 3 and 4 o’clock positions. The furthest planet has shifted the least, still generally at 10 o’clock. Also around the black circle, which has a small yellow star icon within it, are blotches of dark blue, light blue, and white that form a ring. The blotchy texture is more distinct closer to the black circle and gradually fades into the main blue background as distance from the black circle increases.
Labels: 10/26/2012
There are three text labels and one graphic overlay. A white scale bar approximately the length of a quarter of the image’s width is labeled “50 AU.” The small blue-white dot at 4 o’clock, which is nearest to the black circle, is labeled “Closer planets orbit faster.” The faint blue-white dot toward 10 o’clock is labeled “Planets orbit counterclockwise.”
Caption: 10/26/2012
With multiple observations, it is clear that this is a planetary system viewed from above.
Stop 5: 10/15/2013
Image Description: 10/15/2013
This image reveals the same patch of sky, now seen on 10/15/2013. The same four small blue-white dots, as seen in the prior stop, have shifted slightly counterclockwise. They still surround the black circle and are larger and brighter than in the prior stop. Also around the black circle, which has a small yellow star icon within it, are blotches of dark blue, light blue, and white that form a ring. The blotchy texture is more distinct closer to the black circle and gradually fades into the main blue background as distance from the black circle increases.
Labels: 10/15/2013
There are three text labels and four graphic overlays. Each of the four blue-white dots, the four planets, have wide dashed white rings to indicate their different orbital paths. Arrows show their counterclockwise orbital direction. The orbit of the closest planet is labeled “About 54 years” near 8 o’clock. The second closest planet’s orbit is labeled “About 110 years” near 4 o’clock, and the third closest planet’s orbit is labeled “About 233 years” at 1 o’clock.
Caption: 10/15/2013
More observations help us predict full orbits and notice interesting relationships between the orbits.
Stop 6: 7/17/2014
Image Description: 7/17/2014
This image reveals the same patch of sky, now seen on 7/17/2014. The same four small blue-white dots, as seen in the prior stop, have shifted slightly counterclockwise around the black circle. The closest planet has moved the most since the first stop, and is now at the 3 o’clock position. The second closest planet is at 4 o’clock, while the third closest planet is at 1 o’clock. The furthest planet has shifted the least, still generally in the 10 o’clock position. Also around the black circle, which has a small yellow star icon within it, are blotches of dark blue, light blue, and white that form a ring. The blotchy texture is more distinct closer to the black circle and gradually fades into the main blue background as distance from the black circle increases.
Labels: 7/17/2014
There are three text labels. The blue-white dot toward 2 o’clock is labeled “Formed here or migrated here?” The blue-white dot at 4 o’clock is labeled “Atmospheric composition?” In the top left corner, a portion of the blue background is labeled “More planets?”
Caption: 7/17/2014
Direct imaging of the HR 8799 system provides some answers, and also leads to many new questions.
