TVLM513-46546: A New Magnetic Star Found

A dwarf star with a surprisingly magnetic personality and a huge hot spot covering half its surface area is showing astronomers that life as a cool dwarf is not necessarily as simple and quiet as they once assumed.

Using four of the world’s most powerful telescopes, astronomers have found a bizarrely magnetic star with some very strange features. The M-type dwarf has a massive “hot spot”, which covers half of its surface area, and an unusually active magnetic field. The star lies about 35 light-years away in the constellation Boötes. If these strange “anomalies” turn out to be common for M-type stars, astronomers will have a radically altered view of the ultracool dwarfs.

According to Dr. Edo Berger, Princeton University:

We find a hot spot that covers half of the surface of the star like a giant lighthouse that rotates in and out of our field of view. We still do not know why only half of the star is lit up in hydrogen and if this situation remains unchanged over days, weeks, years, or centuries.

TVLM513-46546 - Gemini Observatory/ Dana Berry, SkyWorks Digital Animation
(Image credit: Artist’s rendition of what the magnetic fields and surface might look like on TVLM513-46546. Gemini Observatory artwork by Dana Berry, SkyWorks Digital Animation.)

This is amazing news. QuickFacts about TVLM513-46546

  • Mass is about 8-10% that of the Sun
  • Luminosity is about 0.02% that of the Sun’s brightness
  • Spectral Type is M9 dwarf
  • Age is at least 1 billion years old
  • Located about 35 light years away in constellation Bootes
  • Surface temperature is about 2400K (2127 Celsius)
  • Rotation period about 2 hours

=> More information: Odd Little Star has Magnetic Personality