ESPRESSO Archives

Selected spectra of Teegarden’s star around the Hα line to demonstrate the line shape during quiescent phases and all flares. The spectra of activity level (1) are shown in green, of activity level (2) in blue, and of activity level (3) in red. The flare spectra are shown in magenta. There are a few spectra showing peculiar line shapes with broad additional line components either in absorption or emission (cyan lines). The dashed vertical line marks the central wavelength of Hα. The normalisation wavelength intervals are located well outside any broad wings at 6537.4–6547.9 and 6577.9–6586.4 Å. For the shown spectra the statistical errors are insignificant. -- astro-ph.SR

Astronomy & Telescopes, Imaging & Spectroscopy, Status Report

Coronal And Chromospheric Activity Of Teegarden’s Star

by Keith CowingApril 4, 2025September 18, 2025

Teegarden’s star is a late-type M-dwarf planet host, typically showing only rather low levels of activity. In this paper we present an extensive characterisation of this activity at photospheric, chromospheric, […]

This plot shows the current sensitivity of detecting planets around Barnard’s Star using the MAROON-X Red channel and ESPRESSO data. -- astro-ph.EP

Astronomy & Telescopes, Barnard's Star, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Press Release, Stellar Cartography

Four Sub-Earth Planets Orbiting Barnard’s Star From MAROON-X And ESPRESSO

by Keith CowingMarch 17, 2025March 17, 2025

Barnard’s Star is an old, single M dwarf star that comprises the second-closest extrasolar system. It has a long history of claimed planet detections from both radial velocities and astrometry.

TESS target pixel files for sector 6 tpfplotter (Aller et al. 2020; the code is publicly available at www.github.com/jlillo/tpfplotter). Orange squares identify the aperture masks used to extract the light curve. Sources cross-matched with the Gaia DR3 catalog are indicated by red dots, whose sizes are scaled with their relative magnitude, compared to that of TOI-512. The pixel scale is 21′′ pixel−1

Astronomy & Telescopes, Exoplanets, -moons, -comets, Status Report, Stellar Cartography

TOI-512: Super-Earth Transiting a K-type Star Discovered by TESS and ESPRESSO

by Keith CowingFebruary 21, 2025February 21, 2025

One of the goals of the ESPRESSO guaranteed time observations (GTOs) at the ESO 8.2m telescope is to follow up on candidate planets from transit surveys such as the TESS […]

TESS target pixel file for HD 20794. No nearby sources are detected by the Gaia DR3 catalog up to a contrast magnitude of +6 within the TESS aperture. -- -- astro-ph.EP

Astronomy & Telescopes, Atmospheres, Climate, Weather, Exoplanets, -moons, -comets, Habitable Zones, Imaging & Spectroscopy, Status Report

Revisiting the Multi-planetary System of the Nearby star HD 20794: Confirmation of a Low-mass Planet in the Habitable Zone of a Nearby G-dwarf

by Keith CowingFebruary 4, 2025February 4, 2025

Close-by Earth analogs and super-Earths are of primary importance because they will be preferential targets for the next generation of direct imaging instruments. Bright and close-by G-to-M type stars are […]

Top: Transmission Spectroscopy showing extra absorption in the Na doublet’s core lines across different global abundances, measured in PPM. This plot compares three injected models, illustrating the presence or absence of TiO and VO. It features one example with error bars plus a main strand after several runs. In light blue, regions below 200 ppm are highlighted, indicating areas under the estimated error threshold coming from models without signals. Bottom: Three examples of Transmission Spectroscopy in PPM are presented. Black points represent data binned by a factor of 100, the light blue area denotes a 95% confidence interval, magenta highlights the core lines, and red dashed lines indicate the standard deviation of the continuum. Below these plots are normalised flux profiles centred on the core lines, with a dashed blue line marking the Na doublets. -- astro-ph.EP

Astrochemistry, Astrogeology, Atmospheres, Climate, Weather, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Status Report

A Closer Look at LTT 9779b: The ESPRESSO Endeavour to Pierce the Atmospheric Veil

by Keith CowingFebruary 3, 2025February 2, 2025

The proliferation of exoplanet discoveries in exotic environments like the Neptune desert challenges our understanding of planetary atmospheres under intense irradiation. The unexpected discovery of LTT9779 b, an ultra-hot Neptune […]

RV dataset of HD 20794 for the different datasets. The HARPS RVs have been extracted using YARARA (Cretignier et al. 2021a, 2023). For ESPRESSO, RVs have been extracted with sBART (Silva et al. 2022). -- Astronomy and Astrophysics

Astronomy & Telescopes, Exoplanets, -moons, -comets, Habitable Zones, Imaging & Spectroscopy, Press Release

A Super-Earth Laboratory For Searching Life Elsewhere In The Universe

by Keith CowingFebruary 2, 2025February 1, 2025

‘‘Are we alone in the Universe?’’ For thousands of years, this question was confined to philosophy, and it is only very recently that modern science has begun to provide solid […]

Exoplanet HD 20794 d -- University of Oxford

Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Exoplanets, -moons, -comets, Habitable Zones, Press Release, Water/Hycean Worlds & Oceanography

Existence Of Exoplanet HD 20794 d In A Habitable Zone Confirmed

by Keith CowingJanuary 28, 2025January 28, 2025

An international team has confirmed the discovery of a super-Earth orbiting in the habitable zone of a nearby Sun-like star. The planet was originally detected two years ago by Oxford […]

Various reduction steps applied for an individual ESPRESSO order of DS1. (a) Before telluric removal with molecfit. (b) After telluric removal with molecfit and shifted to the stellar rest frame. (c) Each spectrum is placed on a common blaze function (see Sect. 2.4). (d) Residuals after division through by the mean out-of-transit spectrum, weighted on their uncertainties. This panel shows the final data product used in the molecfit preprocessing analysis. (e) Residuals after division through by the mean out-of-transit spectrum, weighted on their uncertainties, and subtraction of the SysRem model. This panel shows the final data product used in the SysRem preprocessing analysis. It is worth noting that for this procedure, we do not perform any preceding telluric removal (i.e., Sect. 2.4, Step (2)). (f) A magnification of panel (e) showing the wavelength shifts caused by each injected model. The planetary velocity curve for P2 is shown as a white dashed curve, whereas the slower moving planet’s (P12) velocity curve is shown as a white dotted curve. -- astro-ph.EP

AI - Data - Apps - Cybernetics, Astronomy & Telescopes, Atmospheres, Climate, Weather, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Status Report

Assessing Methods for Telluric Removal On Atmospheric Retrievals of High-resolution Optical Exoplanetary Transmission Spectra

by Keith CowingOctober 29, 2024October 29, 2024

Recent advancements in ultra-stable ground-based high-resolution spectrographs have propelled ground-based astronomy to the forefront of exoplanet detection and characterisation. Retrieving accurate atmospheric parameters depends on accurate modelling and removal of […]

ESPRESSO RV measurements (right) and GLS periodograms (left) of GJ 699 after subtracting the median of each dataset before (E18) and after (E19) the intervention in June 2019. Also shown are RV measurements from the ESPRESSO Data Reduction Software (DRS; top), from the S-BART template matching (TM) code (middle), and from the line-by-line LBL code (bottom).-- astro-ph.EP

Alpha Centauri, Astronomy & Telescopes, Barnard's Star, Exoplanets, -moons, -comets, Habitable Zones, Imaging & Spectroscopy, Status Report

A Sub-Earth-mass Planet Orbiting Barnard’s Star

by Keith CowingOctober 4, 2024

Barnard’s star is a primary target within the ESPRESSO guaranteed time observations (GTO) as it is the second closest neighbour to our Sun after the α Centauri stellar system.

This artist’s impression shows Barnard b, a sub-Earth-mass planet that was discovered orbiting Barnard’s star. Its signal was detected with the ESPRESSO instrument on ESO’s Very Large Telescope (VLT), and astronomers were able to confirm it with data from other instruments. An earlier promising detection in 2018 around the same star could not be confirmed by these data. On this newly discovered exoplanet, which has at least half the mass of Venus but is too hot to support liquid water, a year lasts just over three Earth days.Credit:ESO/M. Kornmesser

Astronomy & Telescopes, Barnard's Star, Exoplanets, -moons, -comets, Habitable Zones, Imaging & Spectroscopy, Press Release

A Sub-Earth Mass Planet Has Been Discovered Orbiting Barnard’s Star

by Keith CowingOctober 1, 2024October 1, 2024

Using the European Southern Observatory’s Very Large Telescope (ESO’s VLT), astronomers have discovered an exoplanet orbiting Barnard’s star, the closest single star to our Sun. On this newly discovered exoplanet, […]