Monday, November 12 , 2018, 5:37 pm | Fair 65º

 
 
 
 

UCSB Scientist Helps Discover Fastest-Rotating Massive Star Ever Recorded

Astrophysicist Matteo Cantiello had previously predicted the possibility of observing such a star

An international team of scientists has found the fastest-rotating massive star ever recorded. The star spins around its axis at the speed of 600 kilometers per second at the equator, a rotational velocity so high that the star is nearly tearing apart because of centrifugal forces.

Matteo Cantiello
Matteo Cantiello (Tullio Rossi photo)

This confirms a prediction put forward by astrophysicist Matteo Cantiello, a postdoctoral fellow with UCSB’s Kavli Institute for Theoretical Physics, who contributed to the discovery published this week in the Astrophysical Journal Letters.

The observations were made at the European Southern Observatory’s Very Large Telescope, at the Paranal Observatory in Chile, as part of a survey of the heaviest and brightest stars in a region called the Tarantula Nebula.

The Tarantula Nebula is a region of star formation located in a neighboring galaxy called the Large Magellanic Cloud, about 160,000 light years from Earth. The reported star, VFTS 102, is extremely hot and luminous, shining about 100,000 times more brightly than the sun. According to the research team, this star had a violent past and was ejected from a double star system by its exploding companion star.

Cantiello and collaborators explained that stars could reach such rapid rotation via a “cosmic dance” with another star so close that gravity strips gas from its surface.

“This gas falls onto the companion star, increasing the mass and spinning it up,” Cantiello said. “Similar to a tennis ball spinning fast after being hit by a glancing blow, a star rotates quickly after being hit off-center by the in-falling gas.”

Cantiello previously predicted the possibility of observing this type of star. He reported this theoretical finding with Sung-Chul Yoon, Norbert Langer and Mario Livio in a paper published in 2007 in Astronomy & Astrophysics Letters. This theoretical investigation of stars in binary systems predicted extreme rotational velocities after mass accretion. The observed rotational velocity for the star agrees with this prediction.

The star is unusual not only because it rotates so fast, but also because it is moving away from its neighboring stars at a velocity of about 70,000 miles per hour, or 30 kilometers per second.

“Having been part of a binary system could explain this space oddity,” Cantiello said. “It has been known for over 40 years that a star in a massive binary system can be shot away from its surroundings when the companion ends its life in a spectacular explosion called a supernova. In our theoretical calculations we noticed that the ‘spun-up’ star would also be moving from its surroundings at a high rate. It is very exciting to find a star that matches both of these predictions.”

The star is located close to a pulsar and a supernova remnant, which may be left over from the companion star that once spun-up the observed star. If confirmed, this would provide additional support for the theoretical explanation put forward by Cantiello and collaborators in 2007.

Cantiello said that this star may produce dramatic fireworks as it dies. Such a rapidly rotating, massive star is believed to be the progenitor of some of the brightest explosions in the universe: gamma-ray bursts. These occur when the star’s fast rotation produces powerful jets of light and matter.

Support Noozhawk Today

You are an important ally in our mission to deliver clear, objective, high-quality professional news reporting for Santa Barbara, Goleta and the rest of Santa Barbara County. Join the Hawks Club today to help keep Noozhawk soaring.

We offer four membership levels: $5 a month, $10 a month, $25 a month or $1 a week. Payments can be made using a credit card, Apple Pay or Google Pay, or click here for information on recurring credit-card payments and a mailing address for checks.

Thank you for your vital support.

Become a Noozhawk Supporter

First name
Last name
Email
Select your monthly membership
Or choose an annual membership
×

Payment Information

Membership Subscription

You are enrolling in . Thank you for joining the Hawks Club.

Payment Method

Pay by Credit Card:

Mastercard, Visa, American Express, Discover
One click only, please!

Pay with Apple Pay or Google Pay:

Noozhawk partners with Stripe to provide secure invoicing and payments processing.
You may cancel your membership at any time by sending an email to .(JavaScript must be enabled to view this email address).

  • Ask
  • Vote
  • Investigate
  • Answer

Noozhawk Asks: What’s Your Question?

Welcome to Noozhawk Asks, a new feature in which you ask the questions, you help decide what Noozhawk investigates, and you work with us to find the answers.

Here’s how it works: You share your questions with us in the nearby box. In some cases, we may work with you to find the answers. In others, we may ask you to vote on your top choices to help us narrow the scope. And we’ll be regularly asking you for your feedback on a specific issue or topic.

We also expect to work together with the reader who asked the winning questions to find the answer together. Noozhawk’s objective is to come at questions from a place of curiosity and openness, and we believe a transparent collaboration is the key to achieve it.

The results of our investigation will be published here in this Noozhawk Asks section. Once or twice a month, we plan to do a review of what was asked and answered.

Thanks for asking!

Click Here to Get Started >

Reader Comments

Noozhawk is no longer accepting reader comments on our articles. Click here for the announcement. Readers are instead invited to submit letters to the editor by emailing them to [email protected]. Please provide your full name and community, as well as contact information for verification purposes only.