Today’s news is torn from the social media and enhanced with actual scientific facts! Catch up on a new comet flying toward us from another Solar System, an alien world with water vapor in its atmosphere, and all the wild activities of our galaxy’s generally calm central supermassive black hole.
Links
C/2019 Q4 (Borisov) – An alien comet
- Bizarre comet from another star system just spotted (NatGeo)
- Interstellar Comet gb00234 (The Astronomer’s Telegram)
K2-18b: An alien world with water vapor
- Hubble Finds Water Vapour on Habitable-Zone Exoplanet for the First Time (press release)
- Water Discovered in the Atmosphere of an Exoplanet in the Habitable zone. It Might Be Rain (Universe Today)
- Water vapour in the atmosphere of the habitable-zone eight-Earth-mass planet K2-18 b (Nature Astronomy)
MEERkat sees bubble blown at centre of Milky Way
- South Africa’s MeerKAT discovers giant radio bubbles at centre of Milky Way (press release)
- Giant balloon-like structures discovered at center of Milky Way (press release)
Milkyway’s central black hole has been feeding
Transcript
Sometimes the coolest news of the day doesn’t come at you from some press release engine or from a newly published paper.
Sometimes… not very often but sometimes, it comes to you from a meme. This morning, I woke to a new version of the hot girl meme that shows the guy, labeled astronomers, looking away from his girlfriend Oumuamua to stare at the hot girl C/2019 Q4 Borisov. For those of you who may have missed it, Oumuamua is an extrasolar object – an object from another solar system – that was discovered in October 2017 by the Pan-STARRS survey as it began it’s passage out of our solar system. Everyone got excited, and papers were written explaining what it might be, and theories ranged from cigar shaped rocks to alien spacecraft. The thing is, it wasn’t discovered until it was on its was out of the solar system, and we just didn’t – and now can’t – get the data we want.
So when I saw this meme implying there is something hotter than Oumuamua… I needed to know what C/2019 Q4 Borisov just might be.
It turns out, this new weird object is a smudge of a comet that was discovered by Ukrainian amatuer astronomer Gennady Borisov back on August 30. In the weeks since its discovery, astronomers have been looking at it with telescopes of increasing size as its orbital elements have been systematically measured.
Yesterday, a new Astronomer’s Telegram was posted with orbital elements based on 129 astrometric positions that were measured over 12.42 days. This set of numbers describes an object on a hyperbolic orbit with an excess speed of 30 km/s… which is a fancy way of saying it’s moving fast enough to escape our solar systems gravitational grasp.
This extrasolar comet will make its closest approach to both the Sun and the Earth in December, when it will be roughly 1.96AU from the Sun and 1.89AU from the earth. This places it out beyond the orbit of Mars.
For the next few months, I anticipate an observing frenzy as everyone with a large enough scope catches their own glance at this object from another star … and since this object was found by an amateur observer, there is a chance you can see it from any scope you may have on hand. I can’t predict what we’ll learn scientifically, but I can tell you that we’ll be here at the Daily Space to report on it when those future papers come out.
In other news exploding on social media, a new paper has been published in Nature Astronomy that describes Hubble Space Telescope observations of the extrasolar planet K2-18b. This awkwardly named planet has been found to not only have water in its atmosphere, but it has also been found in its stars habitable zone. This led to instant questions about “could it have life” and to swarms of astronomers trying to crush that curious enthusiasm. As much as people would like to proclaim that Earth 2.0 has finally been found, this world is actually 8 Earth masses, making it a super earth or a sub-Uranus in Size. It’s atmosphere reflects this, showing itself to be rich in hydrogen and helium, which our atmosphere is not. K2-18b is also orbiting a cool dwarf star, which means it must be much closer to its star to be warm, and is likely experiencing tidal forces from its star… and … if that isn’t enough to make it not an Earth 2.0… this world has likely been blasted with radiation from that small star.
So, not Earth 2.0.
But you should still be excited. Science advances incrementally. Finding water vapor here means we can find water vapor with the technology we have today. It means that we can start measuring just how common it is to find water vapor on other worlds. It means that while we haven’t yet found Earth 2.0, we may not be that far away from making that particular discovery.
Moving farther afield, I have two more stories that are each focused on the region around our galaxy’s central super massive black hole.
The first story comes to us from the MEERkat observatory in South Africa. New observations with this radio telescope array have captured images of bubbles blown into the gas and dust in the central regions of our galaxy during highly energetic events that took place a few million years ago. According to William Cotton, one of the researchers in this study “This eruption was possibly triggered by vast amounts of interstellar gas falling in on the black hole, or a massive burst of star formation which sent shockwaves careening through the galactic centre. In effect, this inflated bubbles in the hot, ionised gas near the galactic centre, energising it and generating radio waves that we eventually detect here on Earth.”
This new image is at resolutions we’ve never had before, and reveals the faintest details we’ve ever seen. While that makes these detections novel, this kind of structure has been seen before, with even older bubbles cropping up in other wavelengths as even larger structures that have had more time to push through the interstellar space.
By looking at these new bubbles in the context of past bubble blowing, we are coming to realize that our galaxy has experienced ongoing low-level activity throughout history.
With that context, no one should be surprised to hear that ongoing activity is being detected today.
The Keck observatory has been observing the center of our galaxy for going on two decades as researcher Andrea Ghez and her team watch the motions of the inner most stars, and put constraints on the nature of our galaxy’s black hole. During recent observing sessions, they have caught flickering as our black holes consumes in falling material. This ongoing consumption hasn’t been observed in the past, and it’s unclear why it is going on now. Black holes can’t reach out and force things to fall in. What can happen is interactions elsewhere in the galaxy can send material in toward the center.
This is the same kind of physics that causes our own Sun to periodically eat comets. Just as the black hole isn’t calling out “Feed Me” and causing new material to fall across it’s event horizon, or Sun isn’t forcing comets to fly into its’ surface. In our own solar system. Interactions in the Oort cloud or Kuiper Belt periodically send new material flying into the inner solar system on paths that lead to that materials destruction. Looking into the heart of the Milky Way, we are also seeing material that has had its own unfortunate interactions that is now being shredded on a Supermassive Blackhole’s event horizon.
We record most shows live, on Twitch. Follow us today to get alerts when we go live.