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JWST helped study exoplanets of the HR 8799 system JWST helped study exoplanets of the HR 8799 system

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JWST helped study exoplanets of the HR 8799 system

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When the JWST space telescope first saw the light in July 2022, it was witnessing a huge research program put together by members of the International Astronomical Union. This list included distant early galaxies, forming planets in gas and dust protoplanetary disks, as well as the end of the “dark ages of the Universe” and the first light. Among the numerous targets, exoplanets could not be absent from the list.

One distant star system has particularly fascinated scientists. 15 years ago, astronomers discovered three exoplanets around the star HR 8799, located approximately 133 light years from Earth. Later, a fourth exoplanet was discovered, all planets were found by direct detection. These are massive planets with wide orbits, which is rare. Also, the HR 8799 system is attractive for observations because it belongs to young stellar systems.

JWST helped study exoplanets of the HR 8799 system

Artist’s illustration of the star HR 8799 and one of its four planets, HR 8799c

That’s why JWST recently observed this system. Thanks to its instruments, including the MIRI infrared instrument and the coronagraph, it was able to provide data that allowed it to study the star system in more detail.

The mass of HR 8799 exceeds 1.5 solar masses, and the luminosity of this star is almost five times that of the Sun. A dust disk has formed around it, and it is a fairly young star – its age is only about 30 million years. Young solar systems are of particular interest because they reveal details about the formation of planets. A new study, authored by Anthony Bocaletti from the Observatory of Paris, was aimed at studying these details.

The HR 8799 system includes four planets: HR 8799 b, c, d and e. They are all massive giants with masses ranging from 5.7 to 9.1 Jupiter masses—the mass boundaries of brown dwarfs—objects that have characteristics between planets and stars. The planets’ orbits range from 16 to 71 astronomical units, and their orbital periods range from 45 to 460 years. The fact that they were discovered 15 years ago is also significant because astronomers have an accumulated history of observations of the HR 8799 system.

The discovery of massive giant planets with orbits greater than 5 astronomical units is rare. Therefore, every discovery of such systems is important. Thanks to the capabilities provided by the MIRI instrument, JWST is able to shed light on unknown aspects of such systems and allow scientists to more fully characterize them. Until recently, technical difficulties in mid-infrared observations have made detailed study of the HR 8799 system challenging.

JWST helped study exoplanets of the HR 8799 system

One of the MIRI JWST images showing HR 8799 and all four exoplanets. Source: Boccaletti et al. 2023

With JWST, scientists were able to refine information obtained from previous observations and gain a clearer understanding of various aspects of the system. The main focus has been on more accurately characterizing the atmospheres of exoplanets.

Despite some uncertainty about their composition and the open question of whether they are brown dwarfs, the JWST observations were able to remove doubts. With planetary temperatures ranging from 900 K to 1300 K, new measurements show that the temperature of planet HR 8799 b is lower than previous measurements suggested. Also, the MIRI instrument was able to unambiguously detect the presence of two chemical compounds in the atmospheres of exoplanets: water and carbon monoxide. In addition, according to the data, scientists have controversial evidence of methane detection, which is additional evidence that these objects are planets and not brown dwarfs, since the latter always clearly exhibit methane content at such temperatures.

The MIRI (Mid-Infrared Instrument) instrument was designed with the potential to apply various filters. Some of them were specifically designed to detect ammonia, as this could be an indicator of the presence of precursors to life on exoplanets. However, data from the four planets in the HR 8799 system showed that they were slightly hotter than the temperature at which ammonia would be expected to be present.

JWST helped study exoplanets of the HR 8799 system

MIRI JWST’s powerful filters put an end to debate about a potential fifth planet around HR 8799. This image helped determine that the object was not a star system. Source: Boccaletti et al. 2023

In addition, the HR 8799 system is notable for the presence of a dust disk that has two belts. Researchers wondered whether the inner edge of the outer belt could indicate the presence of a fifth planet with a mass between Jupiter and Saturn, or whether it was simply a collection of dust. This led to a debate that was resolved by JWST observations. The researchers concluded that the inner edge of the outer belt is a background object unrelated to HR 8799.

This was JWST’s first opportunity to study a young exoplanet system using the MIRI instrument, its filters and its coronagraph. JWST’s MIRI instrument opens up new opportunities for high-contrast imaging in the mid-infrared and provides new avenues for the study of young exoplanetary systems. The main goal of the work was to conduct observations and test various algorithms to determine the best scenario for using the instruments and interpreting the results of future observations.

The data obtained will help optimize tool settings. Due to the high sensitivity of the MIRI coronagraph, it may be difficult to study young star systems with its help. This is only the first use of the instrument, and the extreme sensitivity of the coronagraph can make detecting and interpreting observations of young systems challenging, including potential confusion due to the appearance of background galaxy data.

The authors of the work note that ways for improvements have already been outlined, and their results will be useful for further improving observations and research.

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This ultra-cheap $75 smartphone offers a “premium” design and a 90Hz screen. Infinix Smart 8 HD unveiled

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This ultra cheap 75 smartphone offers a premium design and a

Infinix has announced the Smart 8 HD smartphone with a price of just $75. At the same time, the device is equipped much better than many smartphones priced at $100-120.

This ultra-cheap $75 smartphone offers a

But it’s worth starting not even with this, but with design. As you can see, Infinix does not betray itself and even made an ultra-budget smartphone so that it stands out: the back cover seems to have a relief pattern. The company itself even uses the expression “premium design,” but this, of course, is on its conscience.

This ultra-cheap $75 smartphone offers a

From a technical point of view, the device is not bad, and for such a price it is very good. It is based on the Unisoc T606 SoC, which scores about 240,000 points in AnTuTu 10. There is 3 GB of RAM, 64 GB of flash memory, a 13-megapixel main camera and a 5000 mAh battery. And the 6.6-inch screen with HD+ resolution also supports a frame rate of 90 Hz. In addition, there is an element that imitates the Dynamic Island of the iPhone.

It remains to add that the dimensions here are 164 x 75.6 x 8.5 mm with a weight of 184 g.

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The only modern smartphone to receive 10 points for repairability from iFixit. Fairphone 5 is very easy to disassemble

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The only modern smartphone to receive 10 points for repairability

iFixit specialists disassembled the Fairphone 5 smartphone to assess its repairability. Like its predecessor, the new product has the maximum.

The only modern smartphone to receive 10 points for repairability from iFixit.  Fairphone 5 is very easy to disassemble

Fairphone smartphones stand out for a number of features: very long support, modular design and the ability to buy and replace these same modules yourself and, as a consequence of the latter, excellent maintainability. According to iFixit, this is 10 points out of 10 possible.

The smartphone has a removable back plastic cover, a battery that can be easily removed like smartphones of the past, many modular components, from the USB-C port to the camera unit, various pointers to simplify the assembly process, and so on.

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ChatGPT began to become lazy and refuse to respond, and the developers say that this behavior formed on its own

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ChatGPT began to become lazy and refuse to respond and

Some time ago, a number of ChatGPT users discovered that the chatbot could become lazy and even refuse to respond at all. OpenAI recognized the problem, and the situation turned out to be very interesting.

ChatGPT began to become lazy and refuse to respond, and the developers say that this behavior formed on its own

created by DALL-E

The developers stated that they had not updated the AI ​​since November 11, and complaints appeared later. This means that this behavior of the chatbot is not a consequence of any changes made by the developers, but formed on its own. However, the authors of the project say that all this does not mean that ChatPGT itself has somehow changed.

To be clear, the point is not that the model has somehow changed since November 11th. It’s just that the differences in model behavior may be subtle – only a subset of the cues may be degraded, and it may take a long time for clients and employees to notice and correct these patterns

OpenAI also said they are looking for ways to fix the problem, but they don’t seem to have found any yet.

Let us remind you that ChatGPT began to behave as if it was too lazy to look for answers to users’ questions. Responses could be slower than usual, or more careless, and sometimes the AI ​​would even say something like “You can do it yourself.” Moreover, this AI behavior most often manifested itself when it was asked to write program code.

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