Part of lost star catalog of Hipparchus found lurking under medieval codex - Ars Technica

Enlarge / Multispectral imaging revealed hidden archetypal substance from St. Catherine's Monastery implicit the apical of faint tracings connected the Codex Climaci Rescriptus palimpsest.

Museum of the Bible/Keith T. Knox/Emanuel Zingg

The Greek astronomer Hipparchus is often called the "father of astronomy." He's credited with discovering the Earth's precession (how it wobbles connected its axis), and calculating the motions of the Sun and Moon, among different achievements. Hipparchus was besides believed to beryllium compiling a prima catalog—perhaps the earliest known effort to representation the nighttime entity to date—sometime betwixt 162 and 127 BCE, based connected references successful humanities texts.

Scholars person been searching for that catalog for centuries. Now, acknowledgment to a method called multispectral imaging, they person recovered what seems to beryllium the first known Greek remnants of Hipparchus' prima catalog. It was hidden beneath Christian texts connected medieval parchment, according to a new paper published successful the Journal for the History of Astronomy.

Multispectral imaging is simply a method that takes disposable images successful blue, green, and reddish and combines them with an infrared representation and an X-ray representation of an object. This tin uncover infinitesimal hints of pigment, arsenic good arsenic hidden drawings oregon writings underneath assorted layers of overgarment oregon ink. For instance, researchers person antecedently utilized the method to reveal hidden text connected 4 Dead Sea Scroll fragments antecedently believed to beryllium blank. And past year, Swiss scientists utilized multispectral imaging to reconstruct photographic plates created by French physicist Gabriel Lippmann, who pioneered colour photography and snagged the 1908 Nobel Prize successful Physics for his efforts. The method corrected for distortions of colour that occurred arsenic a effect of Lippmann's technique.

The existent insubstantial arose from probe into the Codex Climaci Rescriptus, a palimpsest that originated astatine Saint Catherine's Monastery connected the Sinai Peninsula successful Egypt. It consists of 11 idiosyncratic manuscripts, with Aramaic texts of the Old and New Testament and Greek substance of the New Testament, among different content. Those texts person been dated to the 6th, 7th, and 8th centuries, respectively. The codex was kept astatine Westminster College successful Cambridge until 2010, erstwhile Steve Green, president of Hobby Lobby, purchased it from Sotheby's. It's present portion of the Green Collection connected show successful the Museum of the Bible successful Washington, DC, though a fewer folios are stored elsewhere.

Enlarge / The palimpsest was discovered astatine Saint Catherine's Monastery connected the Sinai Peninsula successful Egypt.

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It was communal signifier astatine the clip to scrape cleanable aged parchment for reuse, and that's what was done with the codex. Initially, scholars assumed the older penning was much Christian texts. But erstwhile Peter Williams, a biblical student astatine Cambridge University, asked his summertime students to survey the pages arsenic a peculiar task backmost successful 2012, 1 of them identified a Greek transition by the astronomer Eratosthenes.

That warranted further investigation, truthful Williams turned to scientists astatine the Early Manuscripts Electronic Library successful California and the University of Rochester successful New York to behaviour multispectral imaging of the pages successful the codex successful 2017. The method revealed a afloat 9 folios pertaining to astronomy, dating to betwixt the 5th and 6th centuries—not conscionable the Eratosthenes transition astir prima root myths, but besides a celebrated poem (Phaenomena, circa 3rd period BCE)  describing constellations.

Williams spent a bully information of his clip during the pandemic lockdown studying the resulting images, and 1 time helium noted what seemed to beryllium the coordinates of the constellation Corona Borealis. He promptly contacted subject historiographer Victor Gysembergh of CNRS successful Paris astir his discovery. “I was precise excited from the beginning,” Gysembergh told Nature. “It was instantly wide we had prima coordinates.”

Enlarge / A leafage from the 6th period CE Codex Climaci Rescriptus successful the Museum of the Bible's Green Collection, featuring the Gospel of Matthew 21:27–31.

Gysembergh and his workfellow Emanuel Zingg of Sorbonne University translated the one-page transition arsenic follows:

Corona Borealis, lying successful the bluish hemisphere, successful magnitude spans 9°¼ from the archetypal grade of Scorpius to 10°¼ successful the aforesaid zodiacal motion (i.e. successful Scorpius). In breadth it spans 6°¾ from 49° from the North Pole to 55°¾.

Within it, the prima (β CrB) to the West adjacent to the agleam 1 (α CrB) leads (i.e. is the archetypal to rise), being astatine Scorpius 0.5°. The 4th prima (ι CrB) to the East of the agleam 1 (α CrB) is the past (i.e. to rise) [. . .]10 49° from the North Pole. Southernmost (δ CrB) is the 3rd counting from the agleam 1 (α CrB) towards the East, which is 55°¾ from the North Pole.

But could this transition beryllium attributed to Hipparchus? While they are cautious astir making a definitive attribution, the authors mention respective pieces of grounds that look to nexus the substance to the Greek astronomer. For instance, immoderate of the information are recorded successful an antithetic mode accordant with the lone different surviving enactment of Hipparchus. And the authors were capable to usage astronomical charts to find that the observations recorded successful the substance were astir apt made astir 129 BCE, erstwhile Hipparchus would person been moving connected his catalog.

So far, lone the coordinates for Corona Borealis person been recovered, but the researchers judge it's rather apt Hipparchus mapped the full nighttime entity astatine immoderate point, including each the disposable stars—just similar Ptolemy did successful his later Almagest treatise. Many scholars judge Hipparchus' catalog was 1 of the sources Ptolemy utilized erstwhile compiling his treatise.

In fact, Williams et al. recovered that Hipparchus' calculations of coordinates were really overmuch much close than Ptolemy's—correct to wrong 1 degree. This was an astonishing feat, fixed that the scope had not yet been invented. They surmise Hipparchus astir apt utilized a sighting conduit called a dioptra oregon an armillary sphere to marque his calculations. And they anticipation that different portions of the mislaid prima catalog mightiness yet beryllium recovered lurking successful the monastery's room arsenic imaging techniques proceed to improve.

DOI: Journal for the History of Astronomy, 2022. 10.1038/d41586-022-03296-1  (About DOIs).

Listing representation by Museum of the Bible, 2021/CC BY-SA 4.0