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Another Interstellar Comet Has Arrived

Another Interstellar Comet Has Arrived 94

“Based on the available observations, the orbit solution for this object has converged to the hyperbolic elements shown below, which would indicate an interstellar origin. A number of other orbit computers have reached similar conclusions, initially D. Farnocchia (JPL), W. Gray, and D. Tholen (UoH).”

Remember ‘Oumuamua, the first interstellar object ever discovered in our solar system? You won’t for long as another one was picked up by multiple observers and reported this week by The Minor Planet Center (MPC) at Harvard University. Unlike ‘Oumuamua, this one is definitely a comet and has been identified earlier enough in its trip through the solar system to be analyzed intensely – possibly revealing where it came from and how astronomers can locate more of them.

Another Interstellar Comet Has Arrived 96

‘Oumuamua

“The comet’s current velocity is high, about 93,000 mph [150,000 kph], which is well above the typical velocities of objects orbiting the sun at that distance. The high velocity indicates not only that the object likely originated from outside our solar system, but also that it will leave and head back to interstellar space.”

The BBC reports that object gb00234, now known as Comet C/2019 Q4, was discovered by amateur (but experienced) astronomer Gennady Borisov on August 30th, 2019, at the Crimean Astrophysical Observatory in Bakhchysarai. When he noticed it, C/2019 Q4 was three astronomical units (450 million km) from the Sun. Since then, other astronomers have seen its tail – confirming C/2019 Q4 is a comet – and measured its eccentricity at 3.2, based on current observations. A perfect circle has an eccentricity of 0, while a closed elliptical orbit ranges from 0 to 1. Anything greater than one indicates an arc-shaped trajectory and is likely an interstellar comet or object making a one-time visit. While not confirmed yet, together these make Comet C/2019 Q4 the first ‘true’ comet to visit use from outside our solar system.

Unless it’s a spaceship.

Good point. Anyone?

Karl Battams
@SungrazerComets
Unlike ‘Oumuamua, whose asteroid-or-comet nature still gets debated, this one is definitely a comet. If it is unequivocally interstellar, it’ll be fascinating to see how its composition (spectral properties) compare to the variety we see in comets from our own solar system.

Another Interstellar Comet Has Arrived 98Astrophysicist Karl Battams, from the Naval Research Laboratory in Washington DC, tweeted an end to that comet-asteroid-spaceship-or-what debate which has trailed ‘Oumuamua like a tail (if it had one) since it was discovered hightailing out of here. Comet C/2019 Q4 will have plenty of eyes on it as it will be visible to even low-powered professional telescopes for at least a year, including when it makes its turn around the sun (perihelion) around December 10. However, the MPC leaves an opening for the unusual:

“Absent an unexpected fading or disintegration, [C/2019 Q4] should be observable for at least a year.”

In lieu of seeing windows with aliens waving out of them, an “unexpected disintegration” would be the next coolest thing.

Source: Mysterious Universe

Space

Scientists suggested looking for aliens near black holes

Scientists suggested looking for aliens near black holes 111

Extraterrestrial civilizations can receive energy from black holes. The technologies allowing to do this have already been described by earthly scientists, although so far only in theory. If this assumption is correct, then traces of aliens can be found just below the event horizon, Physical Review D.

The colossal energy that black holes are fraught with can be used by alien civilizations. Scientists who made such an assumption are confident that traces of intelligent extraterrestrial civilizations should be looked for near black holes.

Scientists at Columbia University in New York have suggested that plasma bursts seen near massive black holes could be related to alien activity. According to them, black holes can become an almost limitless source of energy for a technologically advanced civilization.

“We have to understand what the deliberate extraction of energy from a black hole might look like for terrestrial observers. We are trying to establish what signal we should look for, ” astrophysicist Luca Komisso said.

Over the past 50 years, scientists have formulated four ways to get energy from a black hole. The most famous is a 1969 study by the physicist Roger Penrose, who won the Nobel Prize in 2020.

His theory says that matter should be placed in the ergosphere – a chaotic space-time located beyond the event horizon of a black hole. The substance will fall into two parts. One will be absorbed by the black hole, and the second will “bounce” back. According to calculations, as a result of this process, more energy can be obtained than was originally invested.

Penrose considered only one particle, which splits in two. Recent studies are looking at astronomical plasma that occurs in an accretion disk around a black hole. Since plasma has a huge number of particles, it can provide a huge amount of energy.

The authors of the new study noted that they plan to study all available theories about obtaining energy from black holes. They intend to determine which one is more effective.

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Space

In 200 light years from us, six planets emit an amazing “melody”

In 200 light years from us, six planets emit an amazing "melody" 112

Astronomers have discovered a system of six exoplanets orbiting a star with a specific orbital resonance.

The star system known as TOI-178 is located about 200 light years from us and includes six planets, five of which form a resonant chain, that is, they revolve around the central star in a strictly specified rhythm, and their densities, on the contrary, do not follow the regularity we are used to, according to Forbes.

In the video, the melody plays when the planet passes either full orbit or half of it, and when they line up at these points, they begin to play in resonance. TOI-178 is a really strange star system. Its innermost planet orbits in two days, while the slowest in 20. 

A similar orbital resonance is observed, for example, in the satellites of Jupiter: Io, Europa and Ganymede. While the farthest, Ganymede makes one complete revolution, Europa makes two, and the closest to Jupiter Io – four. This means that they play the same melody in different octaves. 

However, the planets orbiting the TOI-178 star are in a much more complex resonance circuit, obeying the 18: 9: 6: 4: 3 rule. This is the longest resonant pattern known among planetary systems.

Only after the discovery of a kind of “melody” of the TOI-178 star system, astronomers discovered the sixth planet. They used resonance rhythm to calculate where the additional planet would be in its orbit. 

An amazing “rhythm dance” was discovered with the Very Large Telescope (VLT) of the European Southern Observatory (ESO) in Chile. However, this is not just an orbital curiosity. 

“The orbits in this system are very strictly ordered. This tells us that since its formation, it has developed extremely smoothly and calmly,” – Yann Alibert explained, co-author of the study at the University of Bern. 

But even if the arrangement of the orbits in the system is so delicately ordered, everything is much worse with the densities of the planets.

“Here we see that a planet as dense as the Earth is located in the neighborhood of a“ bloated ”one, which has a density half that of Neptune. And after it comes a planet with a density like Neptune. not what we’re used to,” Nathan Hara notes, another study author at the University of Geneva.

However, in addition to the fact that astronomers talk a lot about how TOI-178 was formed, they hope that further study of it will provide important clues about how planets form and evolve in planetary systems.

“This contrast between the rhythmic harmony of orbital motions and the disordered densities of planets completely contradicts our understanding of the formation and development of planetary systems,” Adrien Leleu added, an astrophysicist at the University of Bern in Switzerland who led the study. 

map, constellation Sculptor
This map shows the location of the planetary system TOI-178 in the constellation Sculptor. The map includes most of the stars visible to the naked eye under good conditions, and the location of the system is indicated by a red circle.[ – ]+Photo: ESO, IAU AND SKY & TELESCOPE

The article even argues that resonances and density variations found in the TOI-178 star system could make it the “Rosetta Stone” in understanding the formation and evolution of planets. 

If researchers manage to find planets in the “habitable zone” of a star, where liquid water can exist on their surface, this will be an important and turning point for science. 

Scientists hope that by continuing the resonance chain and using ESO’s upcoming Extremely Large Telescope, they will be able to find more planets and capture them. 

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Space

KOI-5Ab, the curious planet that orbits in a system of three suns

KOI-5Ab, the curious planet that orbits in a system of three suns 113
Photo: (Caltech / R. Hurt (IPAC))

To us, the Sun alone seems perfectly normal, but our solar system is actually a strange exception.

Most stars in the Milky Way galaxy have at least one companion star. In a system 1,800 light-years away, astronomers have finally confirmed the existence of a gas giant planet orbiting stars in a triple star system.

Called KOI-5, the system is located in the constellation Cygnus, and the exoplanet was confirmed ten years after it was first detected by the Kepler space telescope.

In fact, the planet – now known as KOI-5Ab – was discovered by Kepler when it began operations back in 2009.

“KOI-5Ab was dropped because it was difficult and we had thousands of other candidates,” astronomer David Siardi of NASA’s Exoplanet Science Institute said.

“There were lighter dives than the KOI-5Ab, and every day we learned something new from Kepler, so the KOI-5 was almost forgotten.”

Exoplanet hunters tend to avoid the complexities of multi-star systems; of the more than 4,300 exoplanets confirmed to date, less than 10 percent are multi-star systems, although such systems dominate the galaxy. As a result, little is known about the properties of exoplanets in multi-star systems compared to those orbiting a lone star.

After Kepler’s discovery, Chardy and other astronomers used ground-based telescopes such as the Palomar Observatory, Keck Observatory, and the Gemini North Telescope to study the system. By 2014, they had identified two companion stars, KOI-5B and KOI-5C.

Scientists were able to establish that the planet KOI-5Ab, is a gas giant that is about half the mass of Saturn and 7 times the size of Earth, and is in a very close five-day orbit around KOI-5A. KOI-5A and KOI-5B, both of roughly the same mass as the Sun, form a relatively close binary system with an orbital period of about 30 years.

KOI-5Ab, the curious planet that orbits in a system of three suns 114

A third star, KOI-5C, orbits the binary system at a much greater distance, with a period of about 400 years – slightly longer than Pluto’s 248-year orbit.

“By studying this system in more detail, perhaps we can understand how planets are created in the universe.”

The discovery was announced at the 237th meeting of the American Astronomical Society.

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