https://lastlightjournal.co Reporting from the observatories and the dark-sky towns. en-US Sun, 14 Jun 2026 09:00:00 GMT https://lastlightjournal.co/post/the-coronado-and-the-coronagraph/ https://lastlightjournal.co/post/the-coronado-and-the-coronagraph/ Sun, 14 Jun 2026 09:00:00 GMT Beatriz Garcia solar Lyot's coronagraph, the instrument that first showed the corona without an eclipse, has a long descendant line. Beatriz Garcia on the original at Climax and the instruments it begot. https://lastlightjournal.co/post/lunar-libration-across-one-synodic-month/ https://lastlightjournal.co/post/lunar-libration-across-one-synodic-month/ Fri, 12 Jun 2026 09:00:00 GMT Iolanda Ferro night-skies The slow wobble of the Moon, observed and sketched over twenty-nine and a half nights from a balcony in Trieste. https://lastlightjournal.co/post/the-observing-chair-the-red-light-and-the-small-things/ https://lastlightjournal.co/post/the-observing-chair-the-red-light-and-the-small-things/ Fri, 12 Jun 2026 09:00:00 GMT Anselm Bauer equipment Anselm Bauer makes the case for a small set of overlooked accessories — a proper observing chair, a calibrated red flashlight, a notebook, a folding table — that change the experience of a night under the sky. https://lastlightjournal.co/post/pic-du-midi-the-old-tower-and-its-quiet-ridge/ https://lastlightjournal.co/post/pic-du-midi-the-old-tower-and-its-quiet-ridge/ Fri, 12 Jun 2026 09:00:00 GMT Anselm Bauer dark-sites At 2,877 metres in the central French Pyrenees, a working observatory and a heritage hotel share a granite summit. France's first dark-sky reserve, certified in 2013, surrounds them. A spring evening at the cable-car station above Bagnères-de-Bigorre. https://lastlightjournal.co/post/the-meteor-camera-network-coming-of-age/ https://lastlightjournal.co/post/the-meteor-camera-network-coming-of-age/ Fri, 12 Jun 2026 09:00:00 GMT Anselm Bauer meteors Anselm Bauer surveys the rapid maturation of amateur all-sky meteor camera networks in Europe and North America, and the modest equipment that puts a useful station in any home observer's garden. https://lastlightjournal.co/post/chandrasekhar-and-the-white-dwarf-limit/ https://lastlightjournal.co/post/chandrasekhar-and-the-white-dwarf-limit/ Tue, 09 Jun 2026 09:00:00 GMT Anselm Bauer history On a 1930 steamer voyage from Madras to Southampton, an eighteen-year-old Indian physics student calculated the maximum mass of a stable white dwarf. The result was rejected, at length and in public, by Arthur Eddington. https://lastlightjournal.co/post/making-a-solar-filter-safely/ https://lastlightjournal.co/post/making-a-solar-filter-safely/ Mon, 08 Jun 2026 09:00:00 GMT Anselm Bauer solar A homemade objective filter, properly built from the correct materials, is safer than many commercial products. Anselm Bauer walks through the procedure, and the rules that have no exceptions. https://lastlightjournal.co/post/the-caldwell-list-thirty-years-on/ https://lastlightjournal.co/post/the-caldwell-list-thirty-years-on/ Mon, 08 Jun 2026 09:00:00 GMT Cosmo Tate catalogues Patrick Moore published his list of 109 deep-sky objects for amateur observers in December 1995, intending it as a companion to Messier. Three decades later, the list is still in print, still used, and still a little controversial. https://lastlightjournal.co/post/radio-meteor-detection-at-home/ https://lastlightjournal.co/post/radio-meteor-detection-at-home/ Fri, 05 Jun 2026 09:00:00 GMT Iolanda Ferro meteors Iolanda Ferro describes the surprisingly accessible practice of detecting meteors by their radio reflections — a technique that works in cloud, in daylight, and through the worst light pollution. https://lastlightjournal.co/post/south-african-astronomical-observatory-winter-sutherland/ https://lastlightjournal.co/post/south-african-astronomical-observatory-winter-sutherland/ Thu, 04 Jun 2026 09:00:00 GMT Beatriz Garcia observatories Late autumn in the Karoo brings the dry season's first cold nights to the SAAO summit. A May visit ahead of the heart of the southern winter observing season. https://lastlightjournal.co/post/albireo-through-four-inch-refractor/ https://lastlightjournal.co/post/albireo-through-four-inch-refractor/ Thu, 04 Jun 2026 09:00:00 GMT Anselm Bauer night-skies The most-shown double star in the sky, seen carefully from a back garden in Lyon, with notes on what the colours actually look like. https://lastlightjournal.co/post/the-cooled-cmos-camera-on-a-small-budget/ https://lastlightjournal.co/post/the-cooled-cmos-camera-on-a-small-budget/ Thu, 04 Jun 2026 09:00:00 GMT Cosmo Tate equipment Cosmo Tate spent a winter learning a sub-five-hundred-dollar dedicated astrocamera and reports honestly on what it does and does not deliver to the beginning imager. https://lastlightjournal.co/post/la-palma-the-island-that-wrote-a-sky-law/ https://lastlightjournal.co/post/la-palma-the-island-that-wrote-a-sky-law/ Thu, 04 Jun 2026 09:00:00 GMT Beatriz Garcia dark-sites In 1988 the Spanish parliament passed a national statute to protect the night sky over the Canary Islands. Nearly forty years later, the law remains the strictest sky-protection legislation in Europe. A visit to the Roque de los Muchachos. https://lastlightjournal.co/post/cecilia-payne-and-the-composition-of-the-stars/ https://lastlightjournal.co/post/cecilia-payne-and-the-composition-of-the-stars/ Tue, 02 Jun 2026 09:00:00 GMT Yael Kahn history In her 1925 Radcliffe doctoral thesis, Cecilia Payne demonstrated that the stars were made overwhelmingly of hydrogen. She was persuaded, against her own data, to soften the claim. https://lastlightjournal.co/post/the-gong-network-and-what-it-watches/ https://lastlightjournal.co/post/the-gong-network-and-what-it-watches/ Tue, 02 Jun 2026 09:00:00 GMT Cosmo Tate solar Six stations around the world, one Sun continuously observed since 1995. Cosmo Tate on the Global Oscillation Network Group and its slow accumulation of solar interior data. https://lastlightjournal.co/post/aoraki-mackenzie-the-largest-reserve-in-the-southern-hemisphere/ https://lastlightjournal.co/post/aoraki-mackenzie-the-largest-reserve-in-the-southern-hemisphere/ Sat, 30 May 2026 09:00:00 GMT Cosmo Tate dark-sites Four thousand three hundred and sixty-seven square kilometres of New Zealand's South Island form the world's largest accredited dark-sky reserve. A late autumn night at Mount John Observatory above Lake Tekapo. https://lastlightjournal.co/post/the-leonids-and-the-memory-of-1833/ https://lastlightjournal.co/post/the-leonids-and-the-memory-of-1833/ Fri, 29 May 2026 09:00:00 GMT Cosmo Tate meteors Cosmo Tate looks back at the great Leonid storms of 1833, 1866, and 1966, and forward to the comparatively quiet shower today's amateur observers will encounter in November. https://lastlightjournal.co/post/zodiacal-light-high-desert-march/ https://lastlightjournal.co/post/zodiacal-light-high-desert-march/ Thu, 28 May 2026 09:00:00 GMT Yael Kahn night-skies The faint cone of scattered interplanetary dust, observed across nine evenings from a turnout on the Mogollon Rim. https://lastlightjournal.co/post/williamina-fleming-and-the-pickering-computers/ https://lastlightjournal.co/post/williamina-fleming-and-the-pickering-computers/ Thu, 28 May 2026 09:00:00 GMT Iolanda Ferro history Hired as Edward Pickering's housekeeper in 1879, Williamina Fleming became, by 1898, the curator of astronomical photographs at Harvard and a discoverer of the Horsehead Nebula. https://lastlightjournal.co/post/the-eyepiece-collection-that-actually-gets-used/ https://lastlightjournal.co/post/the-eyepiece-collection-that-actually-gets-used/ Thu, 28 May 2026 09:00:00 GMT Iolanda Ferro equipment Iolanda Ferro examines her own eyepiece case after twenty-two years of amateur observing and finds that she uses four of the eleven eyepieces inside it. https://lastlightjournal.co/post/vizier-as-the-quiet-infrastructure/ https://lastlightjournal.co/post/vizier-as-the-quiet-infrastructure/ Thu, 28 May 2026 09:00:00 GMT Beatriz Garcia catalogues The Centre de Données Astronomiques de Strasbourg has been quietly assembling the world's working catalogue archive since 1972. A visit to the small staff that keeps it running. https://lastlightjournal.co/post/the-sunspot-drawers-of-locarno/ https://lastlightjournal.co/post/the-sunspot-drawers-of-locarno/ Tue, 26 May 2026 09:00:00 GMT Iolanda Ferro solar At the Specola Solare Ticinese above Locarno, observers have drawn the Sun's surface by hand on most clear days since 1957. Iolanda Ferro on what the practice preserves. https://lastlightjournal.co/post/pic-du-midi-tourists-sleep-at-altitude/ https://lastlightjournal.co/post/pic-du-midi-tourists-sleep-at-altitude/ Mon, 25 May 2026 09:00:00 GMT Yael Kahn observatories The Pic du Midi de Bigorre in the French Pyrenees runs an overnight tourist program inside a working observatory. A two-night stay during the May new moon. https://lastlightjournal.co/post/mitzpe-ramon-the-makhtesh-at-three-a-m/ https://lastlightjournal.co/post/mitzpe-ramon-the-makhtesh-at-three-a-m/ Fri, 22 May 2026 09:00:00 GMT Yael Kahn dark-sites On the edge of an erosion crater in the Negev sits one of the darkest small towns in the Mediterranean basin. A night at the Ramon Crater observatory with a school group from Beersheva. https://lastlightjournal.co/post/the-quadrantids-on-a-january-morning/ https://lastlightjournal.co/post/the-quadrantids-on-a-january-morning/ Fri, 22 May 2026 09:00:00 GMT Yael Kahn meteors Yael Kahn watches the new year's first shower from the Negev plateau, and finds that its short, sharp peak is its great challenge and its small reward. https://lastlightjournal.co/post/winter-hexagon-as-single-naked-eye-object/ https://lastlightjournal.co/post/winter-hexagon-as-single-naked-eye-object/ Wed, 20 May 2026 09:00:00 GMT Anselm Bauer night-skies Six bright stars, one large pattern, and the slow work of seeing the winter sky as a whole rather than a list of constellations. https://lastlightjournal.co/post/henrietta-swan-leavitt-and-the-period-luminosity-relation/ https://lastlightjournal.co/post/henrietta-swan-leavitt-and-the-period-luminosity-relation/ Wed, 20 May 2026 09:00:00 GMT Cosmo Tate history In a brief 1912 note from Harvard, Henrietta Swan Leavitt established the relationship that would give astronomy its first reliable yardstick beyond the Milky Way. https://lastlightjournal.co/post/collimation-tools-and-the-quiet-discipline-of-alignment/ https://lastlightjournal.co/post/collimation-tools-and-the-quiet-discipline-of-alignment/ Wed, 20 May 2026 09:00:00 GMT Anselm Bauer equipment Anselm Bauer compares four collimation tools across a season of Newtonian use, and argues that collimation is not a chore but a small recurring conversation with an instrument. https://lastlightjournal.co/post/henry-draper-catalogue-and-the-women-who-built-it/ https://lastlightjournal.co/post/henry-draper-catalogue-and-the-women-who-built-it/ Wed, 20 May 2026 09:00:00 GMT Beatriz Garcia catalogues Between 1911 and 1924, a small team at Harvard College Observatory classified the spectra of two hundred and twenty-five thousand stars. The catalogue still anchors stellar spectroscopy, and the work remains attributed, correctly, to Annie Jump Cannon. https://lastlightjournal.co/post/vatican-advanced-technology-telescope-mount-graham/ https://lastlightjournal.co/post/vatican-advanced-technology-telescope-mount-graham/ Tue, 19 May 2026 09:00:00 GMT Cosmo Tate observatories The Vatican Advanced Technology Telescope has operated on Mount Graham in Arizona since 1993. A spring visit to a small instrument that runs an unusual research program. https://lastlightjournal.co/post/eclipse-chasing-three-observers/ https://lastlightjournal.co/post/eclipse-chasing-three-observers/ Tue, 19 May 2026 09:00:00 GMT Beatriz Garcia solar Beatriz Garcia talks to three amateur eclipse chasers about what they have learned across decades of pursuit, and what the discipline costs and gives. https://lastlightjournal.co/post/norwich-vermont-the-town-that-zoned-its-sky/ https://lastlightjournal.co/post/norwich-vermont-the-town-that-zoned-its-sky/ Fri, 15 May 2026 09:00:00 GMT Iolanda Ferro dark-sites In 2019 a town of 3,400 in the upper Connecticut River valley quietly adopted one of the most stringent municipal dark-sky ordinances in the United States. Seven years on, the planning office reports back. https://lastlightjournal.co/post/fireballs-and-where-to-report-them/ https://lastlightjournal.co/post/fireballs-and-where-to-report-them/ Fri, 15 May 2026 09:00:00 GMT Anselm Bauer meteors Anselm Bauer walks through the practical mechanics of fireball reporting — what to record in the first ninety seconds, which network to submit to, and why amateur reports matter. https://lastlightjournal.co/post/january-star-party-single-digit-cold/ https://lastlightjournal.co/post/january-star-party-single-digit-cold/ Wed, 13 May 2026 09:00:00 GMT Yael Kahn night-skies What twenty-one observers brought, wore, and saw on a clear night at fourteen below zero in northern Vermont. https://lastlightjournal.co/post/the-forgotten-career-of-petronila-astengo/ https://lastlightjournal.co/post/the-forgotten-career-of-petronila-astengo/ Tue, 12 May 2026 09:00:00 GMT Beatriz Garcia history Between 1898 and 1924, working from a small private observatory in Rosario, Argentina, Petronila Astengo recorded variable-star observations that ended up, mostly unattributed, in the Harvard archives. https://lastlightjournal.co/post/an-equatorial-mount-for-the-home-observer/ https://lastlightjournal.co/post/an-equatorial-mount-for-the-home-observer/ Tue, 12 May 2026 09:00:00 GMT Cosmo Tate equipment Cosmo Tate spent six months learning a small German equatorial mount in a Cambridge driveway, and reports on the experience for the observer who is considering one. https://lastlightjournal.co/post/19th-century-observing-notebook-examined/ https://lastlightjournal.co/post/19th-century-observing-notebook-examined/ Tue, 12 May 2026 09:00:00 GMT Beatriz Garcia catalogues Caroline Furness kept her observing logs at Vassar's small dome between 1894 and 1936. The notebooks survive, and their calligraphy is a small lesson in what scientific record-keeping used to be. https://lastlightjournal.co/post/yerkes-observatory-reopens-private-stewardship/ https://lastlightjournal.co/post/yerkes-observatory-reopens-private-stewardship/ Fri, 08 May 2026 09:00:00 GMT Beatriz Garcia observatories The Yerkes Future Foundation has run the historic Williams Bay observatory since 2020. Five years into the private stewardship, the world's largest refractor is observing again. https://lastlightjournal.co/post/great-sand-dunes-thirty-square-miles-of-quiet-sky/ https://lastlightjournal.co/post/great-sand-dunes-thirty-square-miles-of-quiet-sky/ Fri, 08 May 2026 09:00:00 GMT Beatriz Garcia dark-sites The dune field of southern Colorado is one of the darkest accredited sites in the National Park system. A March night with a ranger, an amateur from Pueblo, and a wind that did not let up until 02:00. https://lastlightjournal.co/post/preparing-for-the-next-mercury-transit/ https://lastlightjournal.co/post/preparing-for-the-next-mercury-transit/ Fri, 08 May 2026 09:00:00 GMT Cosmo Tate solar The next transit of Mercury falls on 13 November 2032. Cosmo Tate on what amateurs are doing in the six years between then and now to be ready. https://lastlightjournal.co/post/minor-showers-worth-your-time/ https://lastlightjournal.co/post/minor-showers-worth-your-time/ Fri, 08 May 2026 09:00:00 GMT Beatriz Garcia meteors Beatriz Garcia surveys the small annual meteor showers that the casual observer overlooks, and argues that the lower rates are part of their attraction. https://lastlightjournal.co/post/planets-visible-tonight-mid-northern/ https://lastlightjournal.co/post/planets-visible-tonight-mid-northern/ Tue, 05 May 2026 09:00:00 GMT Iolanda Ferro night-skies A short field guide to the five naked-eye planets as they appear in the late spring sky from forty degrees north. https://lastlightjournal.co/post/vera-rubin-and-the-spiral-arm-rotation-problem/ https://lastlightjournal.co/post/vera-rubin-and-the-spiral-arm-rotation-problem/ Mon, 04 May 2026 09:00:00 GMT Beatriz Garcia history Through the 1970s, working at Kitt Peak and Lowell Observatories with a young instrument builder named Kent Ford, Vera Rubin measured the rotation of spiral galaxies and forced a question that had been avoidable for forty years. https://lastlightjournal.co/post/the-refractors-blue-halo-and-what-it-tells-you/ https://lastlightjournal.co/post/the-refractors-blue-halo-and-what-it-tells-you/ Mon, 04 May 2026 09:00:00 GMT Anselm Bauer equipment Anselm Bauer on chromatic aberration, the much-maligned purple fringe at the edge of bright stars, and why the inexpensive achromat is still a useful instrument. https://lastlightjournal.co/post/gaia-dr3-and-what-it-enables/ https://lastlightjournal.co/post/gaia-dr3-and-what-it-enables/ Mon, 04 May 2026 09:00:00 GMT Cosmo Tate catalogues Released in June 2022 and now four years into its working life, Gaia DR3 has reshaped what professional and amateur astronomers expect from a catalogue. A small audit of what it has actually changed. https://lastlightjournal.co/post/cerro-tololo-small-telescope-program/ https://lastlightjournal.co/post/cerro-tololo-small-telescope-program/ Sat, 02 May 2026 09:00:00 GMT Beatriz Garcia observatories Above the Elqui Valley, the 0.9-meter and the 1.3-meter at Cerro Tololo still take queue-scheduled time for graduate students and amateur consortia. A May visit to the smaller domes. https://lastlightjournal.co/post/small-college-dome-physics-building-roof/ https://lastlightjournal.co/post/small-college-dome-physics-building-roof/ Wed, 29 Apr 2026 09:00:00 GMT Cosmo Tate observatories The Goodsell Observatory at Carleton College in Minnesota has hosted student observing for one hundred and forty-nine years. Its rooftop 0.4-meter is still on the curriculum. https://lastlightjournal.co/post/the-brecon-beacons-in-winter-a-january-week/ https://lastlightjournal.co/post/the-brecon-beacons-in-winter-a-january-week/ Wed, 29 Apr 2026 09:00:00 GMT Cosmo Tate dark-sites Wales's only Dark Sky Reserve covers 1,344 square kilometres of common land and high moor. A week of observing from a small farmhouse near Libanus produced two clear nights, one partial, and four written off to weather. https://lastlightjournal.co/post/hydrogen-alpha-for-the-amateur/ https://lastlightjournal.co/post/hydrogen-alpha-for-the-amateur/ Wed, 29 Apr 2026 09:00:00 GMT Anselm Bauer solar A Coronado PST, a Lunt LS50, a double-stacked rig in a Munich back garden: Anselm Bauer on what hydrogen-alpha really shows, and what it costs to see it. https://lastlightjournal.co/post/the-geminids-from-a-vermont-pasture/ https://lastlightjournal.co/post/the-geminids-from-a-vermont-pasture/ Wed, 29 Apr 2026 09:00:00 GMT Cosmo Tate meteors Cosmo Tate spent three nights in December 2025 with an amateur observing group near Craftsbury, Vermont. The Geminids did not disappoint, and the cold was instructive.