Undiscovered Stars and Close Exoplanets

TL;DR

Undiscovered nearby objects could include dim red-dwarf systems, brown dwarfs, and rogue planets hidden within roughly 20 light-years of Earth. Teegarden’s Star went unnoticed until 2003 despite being just over 12 light-years away, while WISE 0855-0714 was discovered in 2014 at just over 7 light-years. Read on to see why these objects evade detection and how wide-field sky surveys could reveal them.

Transcript

It often seems like the most mysterious astronomical objects in the Milky Way have a tendency to be hopelessly distant. The nearest known black hole for example, and perhaps this is a good thing, is still three thousand light years away. And even then, this mysterious object known as A0620-00 is only a candidate for a black hole. This black hole ca... Read More

Key Insights

• ✴️ The nearest known black hole candidate, A0620-00, is about 3,000 light years away and exhibits unique behavior, causing the star it orbits to distort into an elliptical shape.
• 📪 Many close star systems, particularly Class M red dwarfs and brown dwarfs, are yet to be discovered due to their dimness.
• 🤩 There is a possibility of finding undiscovered star systems and planets, including potentially habitable ones, in our local area.
• 🤩 Rogue planets, which have been ejected from their original star systems, may contain subsurface oceans and the potential for life.
• 👶 The Large Synoptic Survey Telescope, with its wide-field sky survey capabilities, is expected to make significant discoveries and potentially unveil new mysteries in astronomy.
• 👻 The LSST will allow for real-time monitoring of a large portion of the night sky, promising unforeseen findings similar to the chance discoveries made by Kepler.
• 👶 Exciting upcoming projects in astronomy, such as the LSST, will revolutionize our understanding of the universe and present us with new mysteries to explore.

Questions & Answers

Q: What undiscovered stars and planets could be close to Earth?

Dozens of dim Class M red dwarfs could be awaiting discovery near Earth, along with even harder-to-detect brown dwarfs. Rogue planets expelled from their original systems could also be nearby, and some might have geothermal energy supporting subsurface oceans.

Q: Why might nearby star systems remain undiscovered?

Class M red dwarfs, the most common type of star, are very dim and may not have been noticed on photographic plates. Brown dwarfs are even harder to spot, so proximity alone does not make these systems easy to detect.

Q: What is A0620-00, and why is it considered a black hole candidate?

A0620-00 is a system about 3,000 light-years away in which a K-type star orbits an invisible object in less than 8 hours. Astronomers calculated that object’s mass and concluded it is too massive to be a neutron star, making it a black hole candidate.

Q: How does the suspected black hole in A0620-00 affect its companion star?

The suspected black hole steals material from the nearby star, forming an accretion disk that emits visible light and X-rays. It also distorts the star into an elliptical shape, causing its observed brightness to vary as different surface areas face Earth.

Q: What nearby objects were discovered only recently?

Teegarden’s Star is a red dwarf just over 12 light-years away that remained unknown until 2003. The sub-brown dwarf WISE 0855-0714, just over 7 light-years away, was not known until 2014.

Q: What are rogue planets?

Rogue planets are worlds that were tossed out of their parent star systems and now wander through deep space. A rogue planet with geothermal energy could have a subsurface ocean where life might reside in complete darkness.

Q: How was the Large Synoptic Survey Telescope expected to find nearby objects?

The Large Synoptic Survey Telescope was described as a wide-field instrument designed to image the entire available night sky once every few days. That repeated coverage could reveal nearby objects inside or close to the solar system and capture unexpected astronomical events.

Q: Why was the Large Synoptic Survey Telescope compared with Kepler?

Kepler imaged a small area of the sky once every half hour and found unexpected phenomena while searching for exoplanets, including Tabby’s Star. The Large Synoptic Survey Telescope was expected to offer similar discovery potential by monitoring a much larger portion of the night sky in nearly real time.

Summary & Key Takeaways

• The closest known black hole candidate, A0620-00, is still 3,000 light years away and is observed as a K type star behaving oddly.

• Astronomers have calculated the mass of this candidate object and concluded it is likely a black hole due to its close proximity to the star.

• Nearby star systems, particularly Class M red dwarfs, and rogue planets are still being discovered, offering the possibility of finding new celestial mysteries.