Over the weekend I discovered about Joseph Haydn’s Symphony No. 47, uncommon in that it provides up a few of its treasures in excellent symmetry. Dubbed ‘The Palindrome,’ the symphony’s third motion, Minuetto e Trio, is crafted to play identically whether or not attacked usually – transferring ahead by the rating – or backwards. You may verify this out for your self on this YouTube video, or on this non-auditory reference.
The pleasure of surprising symmetry is profound, and when seen by the eyes of our spacecraft, might be startling. Take into account the storied star Vega. We see this technique from our perspective at a really low inclination angle relative to its rotational axis, as if we had been wanting down from above the star’s pole. This face-on perspective is profoundly attention-grabbing when examined by our space-borne astronomical property. Within the picture beneath, we get two views of Vega’s disk, from Hubble after which JWST.
Picture: The disk round Vega as seen by Hubble (left) and Webb (proper). Hubble detects mirrored gentle from mud the dimensions of smoke particles largely in a halo on the periphery of the 160-billion-kilometer-wide disk. Webb resolves the glow of heat mud in a disk halo, at 37 billion kilometers out. The outer disk (analogous to the photo voltaic system’s Kuiper Belt) extends from 11 billion kilometers to 24 billion kilometers. The interior disk extends from the interior fringe of the outer disk down to shut proximity to the star. Credit score: NASA, ESA, CSA, STScI, S. Wolff (College of Arizona), Okay. Su (College of Arizona), A. Gáspár (College of Arizona).
We don’t, after all, have the right symmetry of the Haydn minuet and trio right here, however do discover how clean this disk seems, and notably be aware of the shortage of any embedded planets, the form of massive objects we observe in formation round stars like Beta Pictoris. This vivid star, a summer season object in Lyra for these of us within the northern hemisphere, was nicely studied within the infrared by astronomers utilizing the Spitzer House Telescope, and now we have now the clearest view ever, the topic of two upcoming papers in The Astrophysical Journal. Co-author Andras Gáspár (Steward Observatory, College of Arizona, calls the Vega disk “ridiculously clean.”
The view exhibits layered construction, with Hubble detecting mud on the outer areas of the disk and Webb’s infrared view resolving the hotter mud within the interior disk, the disk on this area being sand-sized as in comparison with the outer halo, whose particles are of the consistency of smoke. These are helpful observations as a result of they provide data on mud motion in circumstellar disks, and in addition level out the stark distinction among the many planetary disks so far noticed. The recent, A-class Vega at 450 million years previous stays a comparatively younger star and we might count on interactions amongst particles within the disk to maintain replenishing it, a course of that continues in our personal a lot older system.
However the place are the planets in formation? Lead writer Kate Su (College of Arizona), says that the shortage of them forces astronomers to rethink the best way they’ve checked out forming planetary techniques. It’s doable to tease out a spot at about 60 AU, however in all places else the disk seems clean, which guidelines out planets bigger than Neptune in outer orbits. Provides Su:
“We’re seeing intimately how a lot selection there may be amongst circumstellar disks, and the way that selection is tied into the underlying planetary techniques. We’re discovering lots out concerning the planetary techniques — even once we can’t see what may be hidden planets. There’s nonetheless loads of unknowns within the planet-formation course of, and I believe these new observations of Vega are going to assist constrain fashions of planet formation.”
Within the second of the 2 papers, lead writer Schuyler Wolff (College of Arizona) and colleagues dwelling in on the star Fomalhaut by the use of comparability, this being a star that could be a shut twin to Vega when it comes to luminosity, distance and age. Because the paper notes, “[T]he Vega disk morphology differs considerably from Fomalhaut,” happening to say:
Vega’s fellow archetypical disk, Fomalhaut, has been extensively studied in scattered gentle (Kalas et al. 2005; Gáspár & Rieke 2020) and exhibits a slender chilly belt from 130-150 au (presumably confined by an undetected planet e.g., Boley et al. 2012) with a scattered gentle halo extending outwards from the belt. The mum or dad planetesimal belt is clearly detected with ALMA (MacGregor et al. 2017), with an estimated mud mass of 0.015±0.010M⊕. Fomalhaut has additionally lately been the goal of groundbreaking JWST observations (Gáspár et al. 2023) displaying the identical slender chilly belt (albeit with a slight radial offset indicative of grain dimension stratification) and halo.
Certainly, Fomalhaut seems to be constructing a planet inside its particles disk, and presumably multiple, these objects appearing as ‘shepherds’ shaping the disk. Any such worlds within the Vega system are clearly a lot smaller, if certainly they exist. Vega’s mud distribution is broad, whereas at Fomalhaut the outer particles ring is the dominant supply of sunshine out there for our statement. Three nested particles belts seem at Fomalhaut.
Nothing higher than a brand new astronomical puzzle, particularly when it challenges our notions of planet formation. You might keep in mind Vega’s function in Heinlein’s Have Spacesuit Will Journey (1958), the place its civilization acts as a type of overseer for Earth, and maybe the ‘Vegan Tyranny’ from James Blish’s Cities in Flight sequence. For that matter, Vega has an vital industrial function in Asimov (the supply of ‘Vegan tobacco’ within the Basis books), seems prominently in Jack Vance’s work, and is after all of nice curiosity to Ellie Arroway in Carl Sagan’s ebook and movie Contact. How fulfilling that it now throws a brand new thriller at us.
The papers are Su et al., “Imaging of the Vega Particles System utilizing JWST/MIRI,” accepted at The Astrophysical Journal (preprint) and Wolff et al., “Deep Seek for a scattered gentle mud halo round Vega with the Hubble House Telescope,” accepted at The Astrophysical Journal (preprint).
