Photo: NASA/ESA

A large cluster of stars 19,000 light-years from Earth harbors something strange: Within the cluster, a neutron star left over after a supernova explosion orbits a star not too different from our Sun.

The big picture: The Chandra observatory has been observing that star system — known as Terzan 5 CX1 — for more than a decade, and in that time, Terzan 5 CX1 has gone from looking like one type of star system to another and back again.

  • As that neutron star orbits the other in the pair, its immense gravity pulls material from the companion star, forming a disk around the neutron star.
  • All that material falling in on the neutron star makes it spin quickly, blowing away any extra material encircling the star and transforming it into what's known as a millisecond pulsar.

Yes, but: Chandra found this star system has gone from behaving like a more typical binary to a millisecond pulsar and then back again.

  • It's not yet clear why the pair has done this dance multiple times, but scientists expect this is a phase in the evolution of these types of star systems.

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NYT: Trump paid $750 in federal income taxes in 2016 and 2017

Photo: Chip Somodevilla/Getty Images

The New York Times has obtained more than two decades' worth of tax-return data from Trump and the companies that make up his business, writing in an explosive report that the documents "tell a story fundamentally different from the one [the president] has sold to the American public."

Why it matters: The Times' bombshell report, published less than seven weeks before the presidential election, lays bare much of the financial information Trump has long sought to keep secret — including allegations that he paid $750 in federal income taxes in 2016 and 2017, and has over $300 million in personal debt obligations coming due in the next four years.

Updated 28 mins ago - Politics & Policy

Coronavirus dashboard

Illustration: Sarah Grillo/Axios

  1. Global: Total confirmed cases as of 6:00 p.m. ET: 32,945,376 — Total deaths: 995,608 — Total recoveries: 22,786,066Map.
  2. U.S.: Total confirmed cases as of 6:00 p.m. ET: 7,105,604 — Total deaths: 204,724 — Total recoveries: 2,750,459 — Total tests: 100,492,536Map.
  3. States: 3 states set single-day coronavirus case records last week — New York daily cases top 1,000 for first time since June.
  4. Health: The long-term pain of the mental health pandemicFewer than 10% of Americans have coronavirus antibodies.
  5. Business: Millions start new businesses in time of coronavirus.
  6. Education: Summer college enrollment offers a glimpse of COVID-19's effect.

How Trump, Biden plan to score at Tuesday's debate

Illustration: Sarah Grillo/Axios

President Trump has been practicing with flashcards and prepping with former New Jersey Gov. Chris Christie before Tuesday's presidential debate.

Behind the scenes: Top aides tell Axios he's been testing his attacks on the campaign trail for weeks, seeing what ignites his crowds or falls flat. One of the biggest themes Trump plans to drive home is his "tough guy" persona, which advisers see as an advantage with voters in key states.