The astronomer Rafael Bachiller reveals to us in this series the most spectacular phenomena of the Cosmos. Pulsating research topics, astronomical adventures and scientific news about the Universe analyzed in depth.

An exceptional white dwarf star has been discovered that presents two faces: the brighter hemisphere is dominated by hydrogen and the other by helium.

stellar corpses

White dwarfs are the corpses that result when small stars, similar in type to our Sun, die.. Indeed, when a solar-type star exhausts its nuclear energy, it collapses under the effect of its own gravity, but the mass is not enough to form a black hole, thus forming a highly compact object, the size of the Earth, but containing a mass comparable to that of the Sun. Of course, our own Sun will also inexorably become a white dwarf; but for this it takes a long time: about 5,000 million years.

The gravity on the surface of these white dwarfs is 100,000 times greater than on the Earth's surface and this causes a segregation in the chemical composition: the heavier atoms (such as iron) sink inwards, while the lighter ones ( such as those of hydrogen and helium) remain in the superficial region.

Normally, hydrogen forms a shallower shell than helium.. But, sometimes, there are convection phenomena that alter this disposition. For example, shortly after the catastrophic collapse that, in the middle of a great glow, gives rise to the white dwarf with a temperature of about 100,000 degrees, the star begins to cool down and the convection in the helium layer causes it to mix with that of hydrogen. Eventually, the helium remains on the surface for a long time as the star continues to get colder and colder.

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These ideas have been corroborated by the discovery of a few white dwarf stars with different percentages of helium on their surfaces, possibly because they are in intermediate stages between the transition from hydrogen to helium mode.. But now a new star has just been discovered which is surprising because it seems like a very extreme case.

Ilaria Caiazzo, a young Italian astronomer working at Caltech, California, was part of a group of researchers who, using the Zwicky Transient Facility (ZTF) telescope at the Mount Palomar Observatory near San Diego, California, were looking for peculiar variable white dwarf stars. During this search, the star ZTF J2033 appeared, which is located about 1,300 light-years away in the constellation Cygnus and rotates dizzyingly every 15 minutes.

The most surprising properties of the white dwarf became apparent in follow-up observations that Caiazzo made using several more powerful ground-based and space telescopes than the ZTF: As the star rotated, its brightness varied along with its chemical composition.. When the brighter hemisphere faces the Earth, only hydrogen is detected and when, after half a turn, the other (darker) hemisphere offers us, only helium is detected.

The researchers found no indication of a companion star or the existence of pulsations that could explain such peculiar behavior.. Therefore, they concluded, the variations must be rooted in the stellar surface.. It is as if the star had two different faces: one bright with hydrogen and the other darker with an abundance of helium.. That is why they have nicknamed her Janus, after the Roman divinity that has two faces (the same god that gives its name to the month January).

Jano white dwarf recreation NASA/ESA/CSA/JWST/Williams et al. Magnetism

To try to explain the peculiar structure of this star, the authors of the study turn to magnetic fields. And it is known that white dwarfs, being so compact and rapidly rotating, can have very intense magnetic fields, much more intense than those that prevail, for example, in the dark spots on the surface of the Sun.

Suppose there are notable differences in magnetic field strength in the two Jano hemispheres.. In one zone (bright hemisphere), the field could be strong enough to prevent convective movements, leaving helium submerged in the depths, while a weaker field in another zone (dark hemisphere) could freely allow convection. causing the hydrogen to sink under the rising mass of helium.

The stellar surface is now at a temperature of about 35,000 degrees, in full cooling transition, between the hydrogen phase and the helium phase.. As the surface temperature continues to drop, it is expected that convection will eventually win out over magnetic effects and that the star will complete its evolution completely covered in helium.

These hypotheses are perfectly reasonable because they fit well with the properties of other white dwarfs that have been found with irregular areas on their surface.. But none as extreme as Jano was known, capable of changing its appearance and its spectrum in just a quarter of an hour.

Caiazzo's article on the. entitled A rotating white dwarf shows different compositions on its opposite faces has been published just a few days ago in the prestigious journal Nature.

Rafael Bachiller is director of the National Astronomical Observatory (National Geographic Institute) and academic of the Royal Academy of Doctors of Spain.

The high summer temperatures have brought with them ticks, an arthropod capable of transmitting more than 50 different diseases with its bite..

These are parasites that reside in a large number of wild and domestic animals, feed on the blood of their hosts and are much more dangerous for humans than is believed, since, according to Fernando de la Calle, a specialist in the Unit of Imported Pathology and International Health of the La Paz Hospital, “the number of people who come to the hospital for this cause is increasing.”

In Spain, with six species of ticks registered by the European Center for Disease Control, the most important diseases for human health are mainly bacterial, such as Lyme disease, button fever, anaplasmosis or tularemia, and parasitic, like babesiosis.

To the list must be added viral diseases, such as encephalitis and hemorrhagic fever caused by the Crimean-Congo hemorrhagic fever virus, which has a mortality rate of 30% without treatment.

Doctor De la Calle has warned that “in recent years” an increase in consultations for tick bites has been detected.. “Now we are in a strong period, after atypical years due to the pandemic and with the recovery of mobility,” explained the specialist.

Specifically, he explained that mainly people go to the consultation for “complications of local infection by bites”. Fundamentally, he has detailed, these are cases of rickettsiosis, Lyme disease and, to a lesser extent, babesiosis and anaplasmosis.

AWARENESS BEFORE THE ALARM

In this sense, the epidemiologist misses “awareness” in the face of “alarm signs” that point to a possible tick bite. All this, he emphasized, seeking “the balance between being informed without being alarmed.”

“You don't have to go crazy, but you do have to be attentive to the symptoms and complications and, if serious, go to specialized units,” he argued.

As a general rule, the parasite takes between 24 and 48 hours to start feeding on the blood, so until then, the risk of transmitting the infection is lower, hence the importance of removing it as soon as possible.

To do this, it is recommended to use tweezers or remove them with your fingers with thin gloves, trying to avoid crushing them or using natural remedies such as oil or alcohol.. The result is, many times, the permanence of part of the oral apparatus in the skin and the formation of a permanent granuloma.. For this reason, the extraction must be slow and meticulous, holding the tick from the head and gently pulling it upwards.

“People tend to remove the tick and little else,” explains the expert, who asks to remain “vigilant, without obsession” for 10 or 14 days when faced with symptoms such as fever or the appearance of a skin rash. Also, in the event of atypical signs on the skin such as a black scab that does not heal or complications such as bleeding gums or bruises.

In this sense, he has highlighted the importance of providing the doctor with as much information as possible so that he can help him relate the symptoms to a tick bite.. This is the case of Rosana Toribio, who was diagnosed with Lyme disease after being labeled “crazy” at first “for going to the ER for a mosquito bite.”

The young woman from Madrid began to feel unwell a few days after taking a route in Tenerife through a ravine “that was super dry”. “When I returned to Madrid I began to feel bad. After three or four days I had a fever, a general malaise, I felt terrible. I had a mosquito bite at first and I didn't give it any importance,” he said.

However, Rosana, a pharmacist by training, decided to go to a hospital, alarmed by the characteristics of the red halo that appeared around the bite.. “At first they labeled me crazy when I went to the ER for a mosquito bite when it surely had nothing to do with the discomfort I felt,” she commented with a laugh.

Fortunately, she reported, the nurse called a doctor who, as soon as she observed the characteristics of the bite, suspected its possible relationship with Lyme disease, a bacterial infection that if not treated immediately can cause multiple health problems. .

Without adequate treatment, Lyme disease becomes chronic, seriously affecting the development of a normal life through acute neurological, cardiac and/or articular manifestations.. In this sense, Rosana is fortunate that this physician related her case to a tick bite.

“After time the sting disappears, the halo disappears, and you no longer relate anything to that route in Tenerife and that sting, which could have taken place several months ago,” he warns.

Crimean-congo fever

In Spain, in addition to Lyme disease, one of the most frequent diseases caused by tick bites is boutonnouse fever, which begins with sudden fever, photophobia, joint pain, myalgia and malaise and can evolve into severe forms and lead to hepatitis, meningoencephalitis or renal failure.

One of the most serious consequences may also be Crimean-Congo hemorrhagic fever (CCF), with 12 reported cases and four deaths in Spain since 2013.

In September 2016, the first human case was diagnosed in the Community, associated with contact with a tick in the province of Ávila, and a second case in a health professional who treated him.. The case detected in Madrid was the first in Western Europe with an autochthonous character, not imported from another geographical area.

Although more rarely, the tick can also cause paralysis of the host by inoculating a neurotoxin.. It generally affects children under 10 years of age and can cause death from respiratory paralysis.

HOW TO AVOID TICKS

To avoid these situations, it is advisable that when you go out into the field you wear appropriate clothing, with long sleeves and pants, and wear closed boots and socks. It is also recommended to wear light-colored clothing, which allows you to easily check if any of these arachnids are camouflaged.

On walks through the natural environment, it is recommended to travel through the central area of the paths, avoiding, as far as possible, contact with the vegetation on the sides.. Special care is required in areas with high soil humidity, that is, areas close to watercourses or flooded areas, with the possible presence of livestock.

In addition, it is advisable to avoid sitting on the ground in areas with a lot of vegetation, use authorized repellents and protect pets with a deworming product.. In the event that it is necessary to handle a domestic animal to clean it, it must be done with gloves.

At the end of the day in the countryside, it is also advisable to examine the whole body and wash the clothes used with hot water. It is important to pay special attention to the armpits, groin, hair, navel and around the waist.

Radio astronomy has made it possible to detect a new type of stellar object. A mysterious object that astronomers say “challenges our understanding of the physics of neutron stars” (a neutron star is what is left behind when a massive supergiant star runs out of fuel, collapses, and explodes as a supernova).

This new source of radio waves has been named GPM J183910 and is located 15,000 light years from Earth, in the constellation Scutum.. Astronomers still do not know the nature of this intriguing object, but this Wednesday they present in the journal Nature what they have been able to find out so far and their hypotheses.

As explained by this international team in which Spanish scientists from the Institute of Space Sciences (ICE-CSIC) participate, “the radio waves emitted by the object, the longest ever detected, suggest that it could be a magnetar or of a white dwarf star.

As detailed in a press release, an ultralong-period magnetar is a rare type of neutron star with extremely strong magnetic fields that can produce strong bursts of energy.. However, they have a second hypothesis: that it is actually a magnetic white dwarf, that is, an advanced stage in the life of a star similar to the Sun.. But none of the current scenarios for those objects, they add, can explain with certainty all the characteristics of this new source of radio waves: it emits radio waves every 21 minutes and, if interpreted as a pulsar, would be the longest-period radiomagnetar. long detected to date, set until recently, magnetars were observed to rotate in periods of a few seconds.

Hidden in plain sight, the object GPM J183910 was discovered thanks to the Murchison Widefield Array (MWA) radio telescope, an astronomical facility located in the outback of Western Australia, in an aboriginal territory called Wajarri Yamaji.

They used the Gran Telescopio Canarias

The research has been led by Curtin University and the International Center for Radio Astronomy Research (ICRAR).. Spaniards Nanda Rea and Francesco Coti Zelati, from the Institute of Space Sciences, led follow-up observations of this new object using the Gran Telescopio Canarias (GTC), which is on La Palma and is the world's largest optical telescope.. They also used ESA's XMM-Newton X-ray telescope, and coordinated the physical interpretation of the results.

As reported by the CSIC, “it is the second long-periodic radio object detected and observed, for the first time, at all wavelengths in 2022 by ICE-CSIC researchers. However, the first discovered long-period radio emitter was transient and only shone in the sky for a few months.. Instead, this new source can be located in observation files dating back to 1988.”

“Discovering two systems of this type in such a short time tells us that they are very common in the universe,” says Nanda Rea, second author of the study, professor at ICE-CSIC and member of the Institut d'Estudis Espacials de Catalunya (IEEC) and second author of the study. “This rare object could challenge our understanding of neutron stars and magnetars, which are some of the most exotic and extreme objects in the universe,” said study lead author Natasha Hurley-Walker.

In January 2022, they published a paper in Nature describing an enigmatic transient object that appeared and disappeared intermittently, emitting strong beams of energy three times an hour. Between July and September of that same year, the team scanned the sky using the MWA telescope. Those of the Indian Giant Metrewave Radio Telescope (GMRT) and the American Very Large Array (VLA) had records of observations dating back to 1988.. That is, pulses from this object had been recorded for the first time 33 years ago, but no one noticed and they had remained hidden.

Not all pulsars produce radio waves. Some are thought to lie below the so-called 'death line', a critical threshold where a star's magnetic field becomes too weak to accelerate the particles responsible for radio waves.

Now this team of astronomers hopes to discover more periodic radio bursts in the future, which could help to finally understand the nature of these enigmatic objects.

Dr. Carmen Herrero died this Saturday from metastatic gastric cancer at the age of 37, as reported by the Castellón Hospital Consortium, where she worked.

The healthcare company stood out in the field of oncology where it gave itself “body and soul” to its patients, as the center points out.

He studied Medicine and Surgery at the University of Valencia to later specialize in Medical Oncology. Likewise, she completed a master's degree in Molecular Biology in Madrid and an external Rotatory at the Massachusetts Hospital in the breast cancer unit.

The doctor stood out for her research on breast cancer. In 2019, she received the Professor Antonio LLombart Rodríguez Award from the Royal Academy of Medicine of the Valencian Community, which allowed her to enter the Royal Academy of Medicine of the Valencian Community as a corresponding Academician.

“To his extraordinary and brilliant curriculum is added the delicacy and sympathy with which he treated his patients. Goodbye, dear doctor. You will always be in the hearts of those of us who have had the fortune to know you,” his colleagues said goodbye.

The secret to protecting memory may lie in a staple of a bodybuilder's diet. Researchers at Rush University Medical Center (United States) have shown that a bodybuilding supplement called beta-hydroxy-beta-methylbutyrate, also called HMB, can help protect memory, reduce plaques and ultimately help prevent progression of Alzheimer's disease.

HMB is not a prescription drug or steroid, but an over-the-counter supplement available at sports and fitness stores.. HMB is commonly used by bodybuilders to increase exercise-induced muscle size and strength while enhancing performance. HMB is considered safe even after prolonged use, with no known side effects.

“This may be one of the safest and simplest approaches to stop the progression of the disease and protect the memory of Alzheimer's patients,” explained Kalipada Pahan, one of those responsible for this research, which has been published in the journal Scientific Cell Reports.

Studies in mice with Alzheimer's disease have shown that HMB successfully reduces plaques and increases neuronal growth factors to protect learning and memory.

Previous studies indicate that a family of proteins known as neurotrophic factors is dramatically decreased in the brains of people with Alzheimer's and have been found to help the survival and function of neurons, which are cells that receive and send messages from the body to the brain. and vice versa.

This new study has shown that, after oral consumption, HMB penetrates the brain to increase these beneficial proteins, restore neural connections and improve memory and learning in mice with Alzheimer's-like pathology, such as plaques and tangles.

The results of the study indicate that HMB stimulates a nuclear hormone receptor in the brain called PPARa that regulates fatty acid transport, which is key to the success of HMB as a neuroprotective supplement.

“If the results obtained in mice with HMB are reproduced in Alzheimer's patients, this would open up a promising avenue for the treatment of this devastating neurodegenerative disease,” Pahan detailed.