Leveraging the advanced capabilities of the Near Infrared Camera (NIRCam) and the Mid-Infrared Instrument (MIRI) onboard the James Webb Space Telescope, a collaborative effort by NASA, ESA, and CSA has yielded a spectacular visual representation of the edge-on protoplanetary disk encircling the Herbig-Haro object HH 30. This celestial phenomenon is situated within the opaque expanse of the LDN 1551 dark cloud, a component of the Taurus Molecular Cloud complex.
This Webb/NIRCam/MIRI shows the Herbig-Haro object HH 30. Image credit: NASA / ESA / CSA / Webb / Tazaki et al.
Herbig-Haro objects manifest as diminutive, luminous patches of nebulosity, intrinsically linked to protostars within regions of active stellar genesis.
These formations were initially documented by the American astronomer Sherburne Wesley Burnham in the 19th century. However, their classification as a distinct category of emission nebula was only established in the 1940s.
The pioneering astronomers who undertook detailed investigations of these objects, and subsequently lent them their names, were George Herbig and Guillermo Haro.
The genesis of Herbig-Haro objects is contingent upon highly specific astrophysical conditions: namely, the expulsion of superheated gas from a nascent star, which then engages in high-velocity collisions with the surrounding ambient gas and particulate matter. These impacts, occurring at speeds reaching up to 250,000 km/h (155,000 mph), generate conspicuous shock waves.
Although they exhibit a diverse spectrum of morphologies, their fundamental architecture remains consistent: twin streams of energized gas, expelled bidirectionally from an incipient star, traverse the interstellar medium.
“HH 30 exemplifies a scenario where this outstreaming plasma coalesces into a slender, collimated jet,” the scientific team elucidated.
“The progenitor star is positioned at one extremity of this jet, obscured by an edge-on protoplanetary disk that it is actively illuminating.”
Through the utilization of Webb’s sophisticated instrumentation, the research cadre conducted an in-depth examination of the HH 30 object.
Supplemental analysis incorporated data procured from the NASA/ESA Hubble Space Telescope and the Atacama Large Millimeter/submillimeter Array (ALMA).
“The long-wavelength observational data acquired by ALMA delineate the spatial distribution of millimeter-sized dust aggregates, which are observed to be concentrated within a confined corridor along the equatorial plane of the disk,” the researchers stated.
“Conversely, Webb’s observations in the shorter-wavelength infrared spectrum reveal the dispersion patterns of finer dust particles.”
“These minuscule particles possess dimensions of only one millionth of a meter — roughly commensurate with the size of a single bacterium.”
“While the larger dust particulates are aggregated in the densest regions of the disk, the finer particles are distributed far more extensively.”
“When integrated with ALMA’s acute radio-frequency observational capacity, the Webb data strongly suggest that substantial dust grains undergo migration within the disk and subsequently settle into a remarkably thin layer,” they further commented.
“The formation of such a narrow, dense dust stratum represents a pivotal developmental phase in the intricate process of planet formation.”
“Within this concentrated zone, individual dust grains aggregate, progressively coalescing to form larger entities such as pebbles and, ultimately, nascent planets.”
“Beyond shedding light on the dynamics of dust grains, the composite imagery from Webb, Hubble, and ALMA reveals several distinct structural components arranged in a nested configuration,” the scientists noted.
“A high-velocity outflow of gaseous material emanates perpendicular to the narrow central disk, at a 90-degree angle.”
“Surrounding this narrow jet is a more expansive, cone-shaped expulsion of matter.”
“Enveloping this conical outflow is a vast nebular structure that scatters the light originating from the young star, which remains embedded within the disk environs.”
“Collectively, this extensive dataset illuminates HH 30 as a dynamically active locale, where both microscopic dust particles and colossal jets play integral roles in the ongoing genesis of new planetary bodies.”
The results of this investigation are slated for publication in the esteemed Astrophysical Journal.
_____
Ryo Tazaki et al. 2025. JWST Imaging of Edge-on Protoplanetary Disks. IV. Mid-infrared Dust Scattering in the HH 30 disk. ApJ, in press; arXiv: 2412.07523
