Technologies

Rare binary star, spotted for the first time, answers a long-standing question

This breakthrough could fill a gap in the stellar evolutionary timeline.

The universe is a star museum. Up close, we have our beloved sun in its middle age. Farther out, we’ll find white dwarfs nearing the end of their days. Peer deeper, and you’ll stumble upon hyper-dense neutron stars on the brink of turning into black holes. Now, for the first time, scientists have uncovered a star exhibit that, for years, has only been a hypothesis.

Technically, the team’s discovery is of a binary star system, or one star orbiting another. In this case, the smaller companion is eating the larger star, and very soon, the sparkly orb being chomped on will become a rare form of white dwarf, or late-stage star, called an extremely low mass, or ELM, white dwarf.

They’ve published a paper explaining their findings in this month’s issue of Monthly Notices of the Royal Astronomical Society.

Though fascinating in itself, the sighting of the deteriorating binary star could also fill an empty slot in a long-standing cosmic puzzle.

«This is exciting; it’s a missing evolutionary link in binary star formation models that we’ve been looking for,» Kareem El-Badry, lead author of the paper and a researcher from the Institute for Theory and Computation at the Harvard-Smithsonian Center for Astrophysics, said in a statement.

Zooming out from the binary star itself, El-Badry’s discovery fills a gap in our knowledge of how ELM white dwarfs are generated in the first place. We know ELM white dwarfs exist, as scientists have already pinpointed them, but these stellar bodies pose a conundrum.

According to astronomical calculations, experts say, for a star to naturally reach the mass of an ELM white dwarf, it would need to have been born over 13.8 billion years ago. The issue is, the universe itself is only 13.8 billion years old — so that doesn’t really make sense with what we know about the cosmos so far.

Therefore, the only way these stars could possibly be formed within the universe’s timeline is if an external force created them. That force, theorists say, could be the gravitational pull of a companion in a binary star system that’s pulling matter away from the other until the latter object becomes an ELM white dwarf. Seems intuitive, but for a long time, that was just a hypothesis.

Scientists have come upon binary star systems called cataclysmic variables where regular, massive stars are being consumed by a companion star. They’ve even recorded ELM white dwarfs with companions no longer consuming them. It’s easy to extrapolate that an intermediate step would involve an almost-ELM white dwarf with a companion star eating away at it, but no one had seen such a sight.

Thanks to El-Badry’s revelatory documentation, the transitional step appears to be proven at last.

Star hunting

El-Badry used a wide array of star data, several astronomical surveys and his own firsthand observations with the Shane Telescope at the Lick Observatory in California to locate the unique binary star. He’d come up with 50 potential candidates of transitional ELM white dwarfs and ultimately zeroed in on 21 options.

«100 percent of the candidates were these pre-ELMs we’d been looking for,» he explained in the statement. «They were more puffed up and bloated than ELMs. They also were egg-shaped because the gravitational pull of the other star distorts their spherical shape.»

Aptly, he compares the importance of this breakthrough to biological studies of organisms. «You go out into the jungle and find an organism. You describe how big it is, how much it weighs — and then you go on to some other organism,» he said. «You see all these different types of objects and need to piece together how they are all connected.»

Like the ever-advancing tree of life, El-Badry’s new evidence of ELM white dwarfs helps to unveil the entirety of our cosmic star gallery. «We found the evolutionary link between two classes of binary stars — cataclysmic variables and ELM white dwarfs — and we found a decent number of them,» he said.

Next, he hopes to delve into the other 29 pre-ELM white dwarf star candidates to enrich the universe’s star museum even further.

Technologies

Bishop Takes Rook: You’ll Be Able to Learn Chess on Duolingo Soon

The course is in beta now but will be available to everyone in a few months.

«Hola, ajedrez» means «Hello, chess» in Spanish. You’ve always been able to learn Spanish on Duolingo. And you’ll be able to learn and practice chess on the language learning app soon. Duolingo announced on April 22 that beta testers can practice the centuries-old board game in Duolingo now, and others will be able to learn the game on the app in a few months.

Chess will be the first new Duolingo course since the app began offering math and music lessons in 2023. And Duolingo hopes that to bring the classic board game to more people of all experience levels.

Duolingo chess lessons aim to be friendly to beginners

I spoke with a Duolingo rep about the upcoming lessons. He said the company wants to continue expanding what people can learn through the app, and chess was an early contender.

Chess is «one of those things that … any age group can learn … but then also something that takes the 10,000-hour theory to really master,» Edwin Bodge, a senior product manager with Duolingo, said. «We thought it would fit with the Duolingo medium really well.»

When I asked why people would use Duolingo over other chess learning sites and tools, Bodge said a lot of other chess content is geared toward advanced users, not newcomers. «We really saw a great opportunity to try and cater to more of a beginner, medium (player) and try and increase access to the game,» he said.

The chess lessons are slightly different from others you might find on Duolingo, like Spanish and math, but the progression system is similar. And from what Duolingo showed me, the lessons really do start at square one, or A1 on a chessboard.

Chess lessons feel similar to other Duolingo lessons

When you start, Duolingo asks how much you already know about chess, like in other lessons on the app. Duolingo will then adjust the lessons according to your response. If you say you’re brand-new to chess and have no knowledge of the game, early lessons will focus on how each piece moves before moving on to capturing other pieces and checking the king. Other lessons are similar to mini-puzzles where you might be asked to capture different pieces using a single piece, like your knight or rook, in four moves or fewer.

You can access hints for each lesson, but if you get something wrong, your opponent will react to show you you’ve left a piece open for capture, like in a real match. And if you keep getting something incorrect, Duolingo will show you what to do. «If you get it wrong multiple times, eventually we’ll show you an arrow that shows you exactly where to move,» Sammi Siegel, a software engineer with Duolingo, said.

If you are subscribed to Duolingo Max and make a mistake in a language lesson, the app can explain the mistake — and what the right solution is — with a feature called Explain My Answer. However, that feature won’t be available with the chess lessons for now. It’s not always easy to explain why something is right or wrong in chess because there are so many millions of different moves.

«We want to get better at fuller explanations,» Siegel said. «There is some mix of AI and model training that we’re hoping to use to better explain why a certain move is wrong.» Because there are so many moves in chess, it’s possible to make moves that could be correct but aren’t the best options. In such instances, Duolingo will show a banner that lets you know that a move isn’t wrong but isn’t necessarily the best move.

Duolingo also said each section represents a range on the Elo rating system, the method by which a chess player’s skills are calculated. As you progress, your lessons will be tougher and more challenging. This is similar to the CEFR language proficiency levels attached to the different language sections in the app.

You’ll also have the opportunity to have «mini-matches» or full-on games against Duolingo’s chess coach, Oscar. These matches will scale in difficulty to challenge you as well, so you aren’t facing a grandmaster-level chess player after your first week of playing the game. But that doesn’t mean you can slack off and play sloppily. If you make a mistake, like leaving your queen open to capture, Oscar will take advantage and leave you scrambling to recover.

While playing against Oscar is good practice, you won’t be able to face off against other players when these chess lessons launch. But Duolingo said matches against other people are something they are looking into, so you might be able to play against a friend over the app in the future. «One of the big reasons why we’re doing this is we think we can get a whole generation of people interested in chess,» Bodge said.

Duolingo’s new chess lessons are now available in the beta version now and will start rolling out on iOS in English in May. Duolingo said it is working to bring these lessons to Android devices and more languages in the coming months.

For more on Duolingo, check out how well the free version prepared me for a trip to Italy and our review of the language learning app. You can also check out our best language learning apps.

Technologies

Today’s NYT Mini Crossword Answers for Sunday, April 27

Here are the answers for The New York Times Mini Crossword for April 27.

Looking for the most recent Mini Crossword answer? Click here for today’s Mini Crossword hints, as well as our daily answers and hints for The New York Times Wordle, Strands, Connections and Connections: Sports Edition puzzles.

Today’s NYT Mini Crossword isn’t too much of a stumper. A lot of words contain A and E, for some reason. Need some help with today’s Mini Crossword? Read on. And if you could use some hints and guidance for daily solving, check out our Mini Crossword tips.

The Mini Crossword is just one of many games in the Times’ games collection. If you’re looking for today’s Wordle, Connections, Connections: Sports Edition and Strands answers, you can visit CNET’s NYT puzzle hints page.

Read more: Tips and Tricks for Solving The New York Times Mini Crossword

Let’s get at those Mini Crossword clues and answers.

Mini across clues and answers

1A clue: Outdoor spot to people-watch, maybe
Answer: STOOP

6A clue: Big name in health insurance
Answer: AETNA

7A clue: Broadway theater helper
Answer: USHER

8A clue: Easy to understand
Answer: CLEAR

9A clue: When many show up to a job interview
Answer: EARLY

Mini down clues and answers

1D clue: What «salsa» literally means
Answer: SAUCE

2D clue: Electric car maker since 2003
Answer: TESLA

3D clue: «… in one ear and out the ___»
Answer: OTHER

4D clue: Tatum ___, youngest-ever Oscar winner (at age 10, for Best Supporting Actress)
Answer: ONEAL

5D clue: Defensive maneuver in fencing
Answer: PARRY

How to play more Mini Crosswords

The New York Times Games section offers a large number of online games, but only some of them are free for all to play. You can play the current day’s Mini Crossword for free, but you’ll need a subscription to the Times Games section to play older puzzles from the archives.

Technologies

Today’s NYT Connections: Sports Edition Hints and Answers for April 27, #216

Hints and answers for the NYT Connections: Sports Edition puzzle, No. 216, for April 27.

Looking for the most recent regular Connections answers? Click here for today’s Connections hints, as well as our daily answers and hints for The New York Times Mini Crossword, Wordle and Strands puzzles.

Connections: Sports Edition might be a breeze, as long as you know your sports-league commissioners. Read on for hints and the answers.

Connections: Sports Edition is out of beta now, making its debut on Super Bowl Sunday, Feb. 9. That’s a sign that the game has earned enough loyal players that The Athletic, the subscription-based sports journalism site owned by the Times, will continue to publish it. It doesn’t show up in the NYT Games app but now appears in The Athletic’s own app. Or you can continue to play it free online.

Read more: NYT Connections: Sports Edition Puzzle Comes Out of Beta

Hints for today’s Connections: Sports Edition groups

Here are four hints for the groupings in today’s Connections: Sports Edition puzzle, ranked from the easiest yellow group to the tough (and sometimes bizarre) purple group.

Yellow group hint: Dunk it.

Green group hint: Get it moving.

Blue group hint: They run the leagues.

Purple group hint: Like house, kind of.