Hubble images TW Hydrae Disc Shadows (annotated)
This Hubble Space Telescope Image shows two side-by -side circles that are photos, taken in 2016 and 2021, of nested discs of gas and dust encircling the star TW Hydrae. The view is looking down on top of the discs. In the left… pic.twitter.com/cGxur8PIt6

— Black Hole (@konstructivizm) June 8, 2024

TW Hydrae is a young T Tauri star located about 196 light-years away in the constellation Hydra. It is surrounded by a protoplanetary disk.

Protoplanetary Disk

• The disk extends from around 1-30 AU from the star and has a large inner cavity or gap extending out to around 2.3 AU.
• The disk shows evidence of multiple snow lines where different volatile molecules like water, carbon monoxide, and methane freeze out and condense onto dust grains.
• ALMA observations have detected the carbon monoxide snow line at around 30 AU, where the diazenylium molecule is concentrated, tracing the edge of the CO snow region.
• The disk has been resolved at high resolution, revealing a series of bright and dark rings.

A M A Z I N G
Sun-like star TW Hydrae.
📷:zooms in on the gap nearest to the star, which is at the same distance as the Earth is from the Sun, suggesting an infant version of our home planet could be emerging from the dust and gas.
S. Andrews (Harvard-Smithsonian CfA), ALMA. pic.twitter.com/Q5m4qhijWD

— ALMA Observatory📡 (@almaobs) January 27, 2022

Chemical Composition

• The inner disk (< 2.3 AU) is depleted in carbon and oxygen, with abundances around 50 times lower than the interstellar medium values.
• This depletion suggests that volatile-rich icy grains are efficiently trapped outside the water ice line, preventing enrichment of the inner disk.
• If CO is the main carbon carrier in ices, dust needs to be trapped efficiently outside the CO ice line at around 20 AU to explain the low C/H ratio.
• Observations of deuterated species like DCN, DCO+, and N2D+ show enhancements at specific disk radii, tracing chemical processes like CO depletion and deuterium fractionation.

TW Hydrae across the spectrum 🤩 #Lyot2022 pic.twitter.com/QsqwxkhsUc

— Jayne Birkby (@jaynebirkby) June 28, 2022

The TW Hydrae disk provides a detailed look at the chemical environment where planets are forming, with clear evidence of snow lines, dust evolution, and volatile depletion shaping the composition of potential planets.

TW Hydrae, the nearest infant star in our galaxy, appears to be spawning a new giant planet in the disk of gas and dust around it. https://t.co/q3hZnatsKC pic.twitter.com/oRUUXTL3Rn

— Corey S. Powell (@coreyspowell) June 28, 2019

References:

The dry and carbon-poor inner disk of TW Hydrae: evidence for a massive icy dust trap

Issue	A&AVolume 632, December 2019
Article Number	L10
Number of page(s)	5
Section	Letters to the Editor
DOI	https://doi.org/10.1051/0004-6361/201936638
Published online	10 December 2019

A Frosty Landmark for Planet and Comet Formation

https://science.nasa.gov/universe/exoplanets/a-frosty-landmark-for-planet-and-comet-formation/

RESOLVING THE CHEMISTRY IN THE DISK OF TW HYDRAE. I. DEUTERATED SPECIES

Chunhua Qi, David J. Wilner, Yuri Aikawa, Geoffrey A. Blake, and Michiel R. Hogerheijde

https://iopscience.iop.org/article/10.1086/588516/pdf

Resolving the chemistry in the disk of TW Hydrae I. Deuterated species

Comments:	12 pages, 12 figures, accepted to ApJ
Subjects:	Astrophysics (astro-ph)
Cite as:	arXiv:0803.2753 [astro-ph]
	(or arXiv:0803.2753v1 [astro-ph] for this version)
	https://doi.org/10.48550/arXiv.0803.2753Focus to learn more
Related DOI:	https://doi.org/10.1086/588516

https://arxiv.org/abs/0803.2753