Pic of the Week: The Shining Nucleus of NGC 7496

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Image (Credit): Barred spiral galaxy NGC 7496. (NASA, ESA, CSA, Janice Lee (NOIRLab), Joseph DePasquale (STScI))

This week’s image from the James Webb Space Telescope shows the barred spiral galaxy NGC 7496, which is over 24 million light-years away from Earth. The glowing center is a supermassive black hole.

Here is the full story about the image from the Webb Space Telescope site:

The spiral arms of NGC 7496, one of a total of 19 galaxies targeted for study by the Physics at High Angular resolution in Nearby Galaxies (PHANGS) collaboration, are filled with cavernous bubbles and shells overlapping one another in this image from Webb’s Mid-Infrared Instrument (MIRI). These filaments and hollow cavities are evidence of young stars releasing energy and, in some cases, blowing out the gas and dust of the interstellar medium surrounding them.

Until Webb’s high resolution at infrared wavelengths came along, stars at the earliest point of the lifecycle in nearby galaxies like NGC 7496 remained obscured by gas and dust. Webb’s specific wavelength coverage allows for the detection of complex organic molecules called polycyclic aromatic hydrocarbons, which play a critical role in the formation of stars and planets. In Webb’s MIRI image, these are mostly found within the main dust lanes in the spiral arms. 

In their analysis of the new data from Webb, scientists were able to identify nearly 60 new, embedded cluster candidates in NGC 7496. These newly identified clusters could be among the youngest stars in the entire galaxy. 

At the center of NGC 7496, a barred spiral galaxy, is an active galactic nucleus (AGN). AGN is another way to refer to an active supermassive black hole that is emitting jets and winds. This glows quite brightly at the center of the Webb image. Additionally, Webb’s extreme sensitivity also picks up various background galaxies, which appear green or red in some instances.

Space Stories: Ancient Water, Nearby Black Hole, and a Lunar Time Zone

Posted on by onespaceman2000
Image (Credit): Illustration showing gaseous water in the planet-forming disc around the star V883 Orionis. (European Southern Observatory)

Here are some recent stories of interest.

—European Southern Observatory: “Astronomers Find Missing Link for Water in the Solar System“

Using the Atacama Large Millimeter/submillimeter Array (ALMA), astronomers have detected gaseous water in the planet-forming disc around the star V883 Orionis. This water carries a chemical signature that explains the journey of water from star-forming gas clouds to planets, and supports the idea that water on Earth is even older than our Sun.

“We can now trace the origins of water in our Solar System to before the formation of the Sun,” says John J. Tobin, an astronomer at the National Radio Astronomy Observatory, USA and lead author of the study published today in Nature. 

—SciTech Daily: “Astronomers Uncover Black Hole Closer to Earth Than Ever Before“

Astronomers have discovered the closest black hole to Earth, the first unambiguous detection of a dormant stellar-mass black hole in the Milky Way. Its close proximity to Earth, a mere 1,600 light-years away, offers an intriguing target of study to advance understanding of the evolution of binary systems.

—New York Times: “The Moon May Get Its Own Time Zone“

What time is it on the moon? Since the dawn of the space age, the answer has been: It depends. For decades, lunar missions have operated on the time of the country that launched them. But with several lunar explorations heading for the launchpad, the European Space Agency has deemed the current system unsustainable. The solution, the agency said last week, is a lunar time zone.

Television: The Mandalorian Returns for a Third Season

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Image (Credit): Poster for season three of The Mandalorian. (Disney)

On March 1, season three of Disney’s The Mandalorian premiered. It was action-packed throughout. We had plenty of time with the main Mandalorian, Din Djar, as well as his sidekick, Baby Yoda, now known as Grogu. But if you were somewhat confused to see the two together again after the ending of season two, you are not alone. Unfortunately, Disney tried to keep another Star Wars series, The Book of Boba Fett, relevant by throwing in a few episodes with Din Djar and Grogu. I do not like these types of crossovers, and I expect others feel the same.

In those crossover episodes we learn that Din Djar needed to make amends for taking off his helmet for Grogu, and Grogu decided to abandon Luke Skywalker for his Mandalorian friend. These are key points that should have stayed within the series rather than sprinkled into other series.

But back to season three and some spoilers from the first episode, so beware. I guess I was caught up in the slow, meticulous storytelling in Andor, so the attack on the Mandalorian ceremony in the first scene rattled me awake. I asked myself, why would a diminished race of Mandalorians hold a ceremony in such a dangerous spot? Were death wishes part of the ceremony as well?

And it did not get much better from there. We then find Din Djar going back to Nevarro to reclaim an earlier killer robot for his next mission. Yet the killer robot almost killed Grogu again? Is it really that hard to find a good droid that you have to pull down a town statue and play with pieces?

But wait, there’s more. It turns out that the killer robot needs a particular part, so Din Djar shoots off with Grogu to find the piece. Yet that is not what he ultimately does (after fighting pirates, of course). Instead, he spends time with whining, helmet-less Mandalorian discussing bathing spots on Mandalore.

I think you get the point. I see a lot of action with this reunited pair but not a lot of consistency in purpose or basic logic to their approach. Again, maybe Andor took me away from the Wild West for a time and I need to get back into the spirit of things again.

So I look forward to episode two this week to see whether or not the series can find its footing again. The first two seasons had a particular magic that I hope to see again.

Update: The second episode for this season was much better than episode one and more focused. Plus, it is always fun to spend time with Amy Sedaris playing Peli Motto. Moreover, we may have a new R2D2.

Study Findings: Framework for the Architecture of Exoplanetary Systems

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Image (Credit): Artist’s rendering of the four classes of planetary system architecture discussed in the paper below. (© NCCR PlanetS, / Tobias Stierli)

Astronomy and Astrophysics abstract:

We present a novel, model-independent framework for studying the architecture of an exoplanetary system at the system level. This framework allows us to characterise, quantify, and classify the architecture of an individual planetary system. Our aim in this endeavour is to generate a systematic method to study the arrangement and distribution of various planetary quantities within a single planetary system. We propose that the space of planetary system architectures be partitioned into four classes: similar, mixed, anti-ordered, and ordered. We applied our framework to observed and synthetic multi-planetary systems, thereby studying their architectures of mass, radius, density, core mass, and the core water mass fraction. We explored the relationships between a system’s (mass) architecture and other properties. Our work suggests that: (a) similar architectures are the most common outcome of planet formation; (b) internal structure and composition of planets shows a strong link with their system architecture; (c) most systems inherit their mass architecture from their core mass architecture; (d) most planets that started inside the ice line and formed in-situ are found in systems with a similar architecture; and (e) most anti-ordered systems are expected to be rich in wet planets, while most observed mass ordered systems are expected to have many dry planets. We find, in good agreement with theory, that observations are generally biased towards the discovery of systems whose density architectures are similar, mixed, or anti-ordered. This study probes novel questions and new parameter spaces for understanding theory and observations. Future studies may utilise our framework to not only constrain the knowledge of individual planets, but also the multi-faceted architecture of an entire planetary system. We also speculate on the role of system architectures in hosting habitable worlds.

Citation: L. Mishra, Y. Alibert, S. Udry, C. Mordasini, A framework for the architecture of exoplanetary systems. I. Four classes of planetary system architecture, Astronomy and Astrophysics (Accepted December 2022).
https://doi.org/10.1126/sciadv.abn2103

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