2 research outputs found
Aqueous Processing of Atmospheric Organic Particles in Cloud Water Collected via Aircraft Sampling
Cloudwater and below-cloud atmospheric
particle samples were collected
onboard a research aircraft during the Southern Oxidant and Aerosol
Study (SOAS) over a forested region of Alabama in June 2013. The organic
molecular composition of the samples was studied to gain insights
into the aqueous-phase processing of organic compounds within cloud
droplets. High resolution mass spectrometry (HRMS) with nanospray
desorption electrospray ionization (nano-DESI) and direct infusion
electrospray ionization (ESI) were utilized to compare the organic
composition of the particle and cloudwater samples, respectively.
Isoprene and monoterpene-derived organosulfates and oligomers were
identified in both the particles and cloudwater, showing the significant
influence of biogenic volatile organic compound oxidation above the
forested region. While the average O:C ratios of the organic compounds
were similar between the atmospheric particle and cloudwater samples,
the chemical composition of these samples was quite different. Specifically,
hydrolysis of organosulfates and formation of nitrogen-containing
compounds were observed for the cloudwater when compared to the atmospheric
particle samples, demonstrating that cloud processing changes the
composition of organic aerosol
TOI-2076 and TOI-1807: Two young, comoving planetary systems within 50 pc identified by TESS that are ideal candidates for further follow up
We report the discovery of two planetary systems around comoving stars: TOI-2076 (TIC 27491137) and TOI-1807 (TIC 180695581). TOI-2076 is a nearby (41.9 pc) multiplanetary system orbiting a young (204 ± 50 Myr), bright (K = 7.115 in TIC v8.1) start. TOI-1807 hosts a single transiting planet and is similarly nearby (42.58 pc), similarly young (180 ± 40 Myr ), and bright. Both targets exhibit significant, periodic variability due to starspots, characteristic of their young ages. Using photometric data collected by TESS we identify three transiting planets around TOI-2076 with radii of R b = 3.3 ± 0.04 R ⊕, R c = 4.4 ± 0.05 R ⊕, and R d = 4.1 ± 0.07 R ⊕. Planet TOI-2076b has a period of P b = 10.356 days. For both TOI-2076c and d, TESS observed only two transits, separated by a 2 yr interval in which no data were collected, preventing a unique period determination. A range of long periods (<17 days) are consistent with the data. We identify a short-period planet around TOI-1807 with a radius of R b = 1.8 ± 0.04 R ⊕ and a period of P b = 0.549 days. Their close proximity, and bright, cool host stars, and young ages make these planets excellent candidates for follow up. TOI-1807b is one of the best-known small (R < 2 R⊕) planets for characterization via eclipse spectroscopy and phase curves with JWST. TOI-1807b is the youngest ultra-short-period planet discovered to date, providing valuable constraints on formation timescales of short-period planets. Given the rarity of young planets, particularly in multiple-planet systems, these planets present an unprecedented opportunity to study and compare exoplanet formation, and young planet atmospheres, at a crucial transition age for formation theory