protostar Archives

General chronology of the early solar system.

Setting The Stage: The Early History Of The Solar System

by Keith CowingAugust 11, 2026August 11, 2026

[astro-ph.EP] This article reviews the early history of our solar system from an astrobiological perspective and presents evidence from meteorites and astronomical observations. The purpose is to trace the formation […]

The figure illustrates the four main phases of low-mass star formation: from the gravitational collapse of the natal core of gas and dust (Prestellar Core), to the main accretion phase (Class 0/I protostar, age ∼104 -105 yr), followed by the protostar and its surrounding protoplanetary disk (Class I/II, age ∼105 -106 yr), and finally the revealed planetary system after the disk has dispersed (Class III, age ∼107 yr). Typical spatial and timescales are indicated for each stage. Generated with Google Gemini 3 Flash and modified. -- [astro-ph.SR]

Habitable Zones

Cradle Of Life: From The Formation Of Stars To Habitable Worlds With The SKAO

by Keith CowingJuly 17, 2026July 17, 2026

[astro-ph.SR] This chapter provides an overview of the different science cases covered by the “Cradle of Life” working group, which aims to leverage the capabilities of the Square Kilometre Array […]

IRAS 15398 JWST NIRSpec spectrum (Program ID 1854, PI: M. McClure), NIRSpec Prism spectrum (Program ID 6161, PI: K. Slavicinska), and MIRI-MRS spectrum (Program ID 2151, PI: Y.-L. Yang) with the radiative transfer model spectrum extracted in a 1” diameter overlaid in black. Data points which hit the noise floor from the G395H and Prism data were removed. A spectrum zoomed in to the NIR CO2 and CO absorption is shown in Appendix E. -- astro-ph.SR

Astrochemistry, Astronomy & Telescopes, Biochemistry & Organic Chemistry, Biophysics, Biosignatures & Paleobiology, Icy Worlds, Imaging & Spectroscopy, Interstellar, Status Report

CORINOS V: Radiative Transfer Effects In Protostellar Ice Observations

by Keith CowingMay 2, 2026May 2, 2026

Recent observations of protostars with the James Webb Space Telescope have revealed unprecedented chemical complexity from their ice absorption features.

Artistic scheme of the VLA 4A/4B binary system, not in scale. Methanol and water absorption features originate from gas located in front of the dust photosphere at 26 µm, which is likely driven by VLA 4B (see text). The photosphere size and location is not certain, but the absorption selectively probes only a layer of sublimated ice, rather than the full bulk envelope, in a location where methanol may desorb more efficiently than water. -- astro-ph.EP

Astrochemistry, Astronomy & Telescopes, Biochemistry & Organic Chemistry, Biosignatures & Paleobiology, Exploration Gear & Tech, Imaging & Spectroscopy, Status Report

High-resolution mid-IR Spectroscopy of SVS 13-A with EXES/SOFIA: The Surprisingly High CH3OH/H2O Ratio In The Planet-forming Zone Of A Solar Mass Protostar

by Keith CowingMarch 24, 2026March 24, 2026

Water and methanol are key components of interstellar ices and gas in star- and planet-forming regions, but direct observations of water in low-mass protostars are challenging due to atmospheric absorption.

CH3OH/H2O column density ratio found in the literature for a wide range of clouds, YSOs and Solar System comets (see Sect 4.1 for the references). The values for molecular clouds, LYSOs and MYSOs reflect the ice composition, while the ratio was measured in the gas-phase for protoplanetary disks and comets. We used open symbols for the protoplanetary disks in which the upper/lower limit on the methanol-to-water column density ratio was estimated combining measurements taken at different wavelength ranges. The upward triangles for the HD 100546 and the IRS 48 disks indicate a lower limit, whereas the downward triangles for DG Tau A and HL Tau indicate a upper limit. The values for HL Tau are taken dividing the 3σ upper limit on the NCH3OH for the three different assumed excitation temperature in Table 2 for the water column density measured by Facchini et al. (2024). -- astro-ph.SR

Astrochemistry, Astronomy & Telescopes, Biochemistry & Organic Chemistry, Biosignatures & Paleobiology, Imaging & Spectroscopy, Status Report

Hunting For Methanol In The Water Rich, Planet Forming Disk Aaround HL Tau

by Keith CowingMarch 13, 2026March 13, 2026

Methanol, the simplest complex organic molecule found in space, is considered a key compound necessary for the formation of chemical species of prebiotic interest. Methanol detections in protoplanetary disks remain […]

B335 intensity map at 8 µm using the JWST MIRI-MRS spectrograph data. Small circles denote the 1.53′′ apertures, big circle denotes the 4.59′′ aperture. The center coordinates of chosen apertures are listed in Table 2. -- astro-ph.SR

Astrochemistry, Astrogeology, Biochemistry & Organic Chemistry, Biosignatures & Paleobiology, Icy Worlds, Status Report

Infrared Spectra Of Methane-containing Ice Mixtures For JWST Data Analysis

by Keith CowingFebruary 19, 2026February 19, 2026

Context. Solid methane (CH4) is an important molecule in interstellar and planetary environments, serving as a precursor to complex organic compounds and a potential biosignature in exoplanetary studies. Despite its […]

Intensity maps at 4.4 µm with the apertures chosen for the fit. Aperture centers and diameters are listed in Table C.1. -- astro-ph.GA

Astrochemistry, Astronomy & Telescopes, Biochemistry & Organic Chemistry, Imaging & Spectroscopy, Interstellar, Status Report

Identification Of Solid N2O In Interstellar Ices Using Open JWST Data

by Keith CowingJanuary 16, 2026January 16, 2026

Context. There are only six molecules containing N-O bond that are detected in gaseous phase in interstellar medium. One of those is nitrous oxide (N2O), which was searched for but […]

The sketch of the protostellar core adopted in this model, including a central source characterised by the bolometric luminosity (L∗) and the stellar temperature (T∗). The inner zone is characterised by the sublimation threshold of dust grains (Tsub) and the threshold radius (rthreshold). The thin shell of hot dust is determined by the shell temperature (Tshell) and its radius (Rshell). The outer region is given by the outer radius (rout). -- astro-ph.GA

Astrochemistry, Biochemistry & Organic Chemistry, Imaging & Spectroscopy, Interstellar, Press Release

One-dimensional And Time-dependent Modelling Of Complex Organic Molecules In Protostars

by Keith CowingJanuary 6, 2026January 6, 2026

Complex organic molecules (COMs), the building blocks of life, have been extensively detected under various physical conditions, from quiescent clouds to star-forming regions.

Optical depth spectra of the YSOs in our sample, shifted vertically for clarity. For illustration purposes, the red lines correspond to a linear combination of four ice mixtures selected from LIDA (3000 monolayers of pure H2O at a temperature of 15 K, H2O:CO2 in the ratio 10:1 at 10 K, CO:CO2 in the ratio 2:1 at 15 K, and pure OCS at 17 K) and provide a reasonable fit to the observations. The corresponding column densities are listed in Table 4. The legend at the top of each panel indicates the ice features discussed in the text and the corresponding wavelengths, to guide the eye. -- astro-ph.GA

Astrochemistry, Astronomy & Telescopes, Biosignatures & Paleobiology, Icy Worlds, Imaging & Spectroscopy, Interstellar, Status Report

First Detection Of Ices In Intermediate-mass Young Stellar Objects Beyond The Milky Way

by Keith CowingSeptember 27, 2025September 27, 2025

Using NIRSpec on JWST, we studied a sample of 15 intermediate-mass (1.8-4.1 Msun) young stellar objects (YSOs) previously identified with MIRI photometry in the low-metallicity NGC 346 star-forming cluster in […]

NASA/ESA/CSA James Webb Space Telescope has provided a fantastic new view of IRAS 04302+2247, a planet-forming disc located about 525 light-years away in a dark cloud within the Taurus star-forming region. Larger image

Astronomy & Telescopes, Exoplanets, -moons, -comets, Interstellar, Status Report

Watching Planet Formation In The IRAS 04302+2247 Disc

by Keith CowingSeptember 8, 2025September 8, 2025

With Webb, researchers can study the properties and growth of dust grains within protoplanetary discs like this one, shedding light on the earliest stages of planet formation.