HIRES Archives

A section of the Rp versus Mp linear-log diagram of known transiting exoplanets with a mass between 10 and 100 M⊕ (measured with an accuracy to within 20%) and a radius between 3 and 10 R⊕. Data taken from TEPCat. The positions of TOI-1274 b and TOI-1694 b are highlighted (this work). Exoplanets inside the green zone are giant planets with sizes and masses between those of Neptune and Saturn. The position of Uranus, Neptune, and Saturn are also marked with red capital letters. -- astro-ph.EP

The GAPS Programme at TNG LXXIV. A Reanalysis Of The Planetary Systems TOI-1272 And TOI-1694 With HARPS-N And Retraction Of The Planetary Interpretation Of TOI-1272 c

by Keith CowingJune 27, 2026June 27, 2026

[astro-ph.EP] Hot Neptunes are close-in exoplanets that occupy a sparsely populated region of parameter space known as the “hot-Neptune desert”.

Light curves of HIP 41378. Upper panel: K2 C5 campaign (long cadence). Bottom panel: K2 C18 campaign (short cadence). The pink curve represents the median of the best-fit model from photometry and RV analysis. The names of the planets are highlighted with their letters. -- astro-ph.EP

A Decade Of Monitoring The HIP 41378’s Planetary System

by Keith CowingJune 25, 2026June 25, 2026

Multi-planetary systems provide key constraints on planet formation and evolution, as their architecture encodes the dynamical history of planets formed within a common protoplanetary disk.

Habitable Zone diagram for the Ross 318 system. The green band indicates the Conservative Habitable Zone boundaries from Kopparapu et al. (2013). The orange star marks Ross 318; the violet circle marks Ross 318 b at a = 0.159 au with Seff = 0.58 S⊕. For comparison, the positions of Venus (0.72 au), Earth (1.00 au), and Mars (1.52 au) around the Sun are indicated. -- astro-ph.EP

Atmospheres, Climate, Weather, Exoplanets, -moons, -comets, Habitable Zones, Space Weather & Heliophysics, Status Report, Stellar Cartography

Detection and Characterization of the Temperate Super-Earth Ross 318 b

by Keith CowingMay 14, 2026May 14, 2026

Ross 318 is an M3.5V red dwarf exhibiting significant magnetic activity and a stellar rotation period of ∼ 51.5 d.

Combined fit results for K2-79 b. Transit fit to the light curve data from K2 long cadence (first row left), TESS long cadence (first row centre), and CHEOPS (first row right). The cadence (29.4 min for K2 long cadence, 120 s for TESS long cadence, and 60 s for CHEOPS) fluxes are plotted in grey, the fluxes binned every 30 min are over-plotted in black, and the fitted transit is shown by the red solid line. The RV fit to the HARPS-N & HIRES RVs is shown in the second row for K2-79 b. Coloured circular points show the phase folded RVs, grey points show these same values in subsequent phases, and the black line shows the best fit Keplerian model. The third row shows the RVs over the full ∼ 9 yr baseline, illustrating the absence of any significant long term trend. -- astro-ph.EP

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

Constraining Small Planet Compositions for Future Missions

by Keith CowingMarch 18, 2026March 18, 2026

Accurate mass and radius measurements of small transiting exoplanets are essential for probing their compositions, formation histories, and potential habitability.

The size of GJ 251 and the orbits of GJ 251 b and c. Stellar size and orbital distances are to scale. In light green we show the optimistic HZ, and in dark green the conservative HZ (Kopparapu et al. 2013, 2014). GJ 251 c orbits directly in a regime where liquid water might be able to exist on its surface. -- astro-ph.EP

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

Discovery Of A Nearby Habitable Zone Super-Earth Candidate Amenable To Direct Imaging

by Keith CowingOctober 28, 2025October 29, 2025

We present the discovery of GJ 251 c, a candidate super-Earth orbiting in the Habitable Zone (HZ) of its M dwarf host star.

[LEFT] GJ 536 b and c in context. The upper panel shows the masses of known planets, for masses below 100 M⊕, and periods shorter than 1000 days, with the planets of the system of GJ 536 highlighted, and the solar system planets as reference. The middle panel shows the same, but as a function of insolation. The lower panel shows the contrast in reflected light of low-mass planets orbiting bright stars (mV < 12), compared to their angular separation to their parent star. The dotted vertical lines indicate the limits in which ANDES wil be able to observe (Palle et al. 2025). The red symbols for the planets of GJ 536 show the potential range of contrasts. The green squares show the position of the ANDES golden sample. [RIGHT] Parameters of the planets of the system of GJ 536, using the adopted (circular) model. -- astro-ph.EP

Astronomy & Telescopes, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Status Report

A Second Low-mass Planet Orbiting The Nearby M-dwarf GJ 536

by Keith CowingSeptember 18, 2025September 18, 2025

GJ 536 is a low-mass star, located 10 pc away from the Sun, that hosts a low-mass planet orbiting with a period of 8.71 days.

Detection and vetting of the candidate exoplanet TOI-1430.01. Panel (a) shows the TOI-1430’s stacked light curve and the detrending model (in red). Panel (b) shows the flattened light curve and the position of the odd (magenta) and even (blue) transits. Panels (c) are a comparison between the mean depths of the odd and even transits; the dashed lines are the mean depths while the shaded colored regions represent the 3σ confidence interval. Panel (d) is the TLS periodogram: the period of the peak is indicated with a green triangle. -- astro-ph.EP

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

Precise Density Measurement of TOI-1430 b, A Young Planet With An Evaporating Atmosphere

by Keith CowingNovember 21, 2024November 21, 2024

Small-sized exoplanets in tight orbits around young stars (10-1000 Myr) give us the opportunity to investigate the mechanisms that led to their formation, the evolution of their physical and orbital […]

S-BGLS (left) and coherence test (right) for HARPS (top) and HIRES (bottom). Red boxes indicate a coinciding dip in significance, which also happens at overlapping time frames. -- astro-ph.EP

Astronomy & Telescopes, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Status Report

The CARMENES Search for Exoplanets Around M Dwarfs. Revisiting the GJ 581 Multi-planetary System with New Doppler Measurements from CARMENES, HARPS, and HIRES

by Keith CowingJuly 26, 2024July 26, 2024

GJ 581 is a nearby M dwarf known to host a packed multiple planet system with 2 super-Earths and a Neptune-mass planet. We present new orbital analyses of the system, […]

The high-resolution ELT instrument ANDES (formerly known as HIRES) will allow astronomers to study astronomical objects that require highly sensitive observations. It will be used to search for signs of life in Earth-like exoplanets, find the first stars born in the Universe, test for possible variations of the fundamental constants of physics, and measure the acceleration of the Universe’s expansion. — ESO Larger image

Astrochemistry, Astronomy & Telescopes, Atmospheres, Climate, Weather, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Press Release

New Instrument To Search For Signs Of Life On Other Planets

by Keith CowingJune 17, 2024

The European Southern Observatory (ESO) has signed an agreement for the design and construction of ANDES, the ArmazoNes high Dispersion Echelle Spectrograph.

TESS target pixel files for TOI-260 for sector 3 (left), and for TOI-286 for sector 1 ( right). The remaining sectors are shown in Appendix A. The target star is labelled as 1 and marked by a white cross in each case. All sources from the Gaia DR3 catalogue down to a magnitude contrast of 8 are shown as red circles, with the size proportional to the contrast. The SPOC pipeline aperture is overplotted in shaded red squares. -- astro-ph.EP

Habitable Zones, Status Report, Water/Hycean Worlds & Oceanography

Three Super-Earths And A Possible Water World From TESS And ESPRESSO

by Keith CowingJune 12, 2024June 12, 2024

Since 2018, the ESPRESSO spectrograph at the VLT has been hunting for planets in the Southern skies via the RV method. One of its goals is to follow up candidate […]

HIRES

The GAPS Programme at TNG LXXIV. A Reanalysis Of The Planetary Systems TOI-1272 And TOI-1694 With HARPS-N And Retraction Of The Planetary Interpretation Of TOI-1272 c

A Decade Of Monitoring The HIP 41378’s Planetary System

Detection and Characterization of the Temperate Super-Earth Ross 318 b

Constraining Small Planet Compositions for Future Missions

Discovery Of A Nearby Habitable Zone Super-Earth Candidate Amenable To Direct Imaging

A Second Low-mass Planet Orbiting The Nearby M-dwarf GJ 536

Precise Density Measurement of TOI-1430 b, A Young Planet With An Evaporating Atmosphere

The CARMENES Search for Exoplanets Around M Dwarfs. Revisiting the GJ 581 Multi-planetary System with New Doppler Measurements from CARMENES, HARPS, and HIRES

New Instrument To Search For Signs Of Life On Other Planets

Three Super-Earths And A Possible Water World From TESS And ESPRESSO

NASA Spaceline Current Awareness List #1,206 2 July 2026 (Space Life Science Research Results)

Older Than The Sun: Astronomers Find New Clues To The Origin Of Interstellar Comet 3I/ATLAS

Carl Sagan Month: Call For Participation

The Habitable Worlds Observatory Technology Development Plan

Searching For The Elusive CH2+ With The James Webb Space Telescope. Another Carbocation To Constrain Astrochemical Networks