The librarian who became Palomar's first female telescope operator, and who discovered her own comets

More times than she tin remember, Jean Mueller stood connected the catwalk of the 200-inch Hale Telescope astatine the Palomar Observatory scanning the nighttime sky, trying to clip the nonstop infinitesimal to adjacent the dome.

An hr and a fractional northeast of San Diego, the Palomar Observatory is owned and operated by Caltech, and arsenic scope operator, Mueller was liable for protecting its instruments from the weather. Inside the structure, a 200-inch reflector captured airy from distant stars successful a clip model important to the observing astronomer’s research. But erstwhile a fog slope rolled closer, Mueller had to marque the call.

“I would get the dome closed wrong a infinitesimal oregon 2 of the fog really hitting it,” said Mueller. “We are vigilant for thing that mightiness harm the mirror. You don’t privation acerb rainfall connected the reflector due to the fact that that’s going to devour the aluminum coating. Ash, combined with humidity, tin beryllium caustic.”

Mueller, a scope relation astatine Palomar from 1985 to 2014, called her way to astronomy “nonstandard.” She had a postgraduate grade successful room subject and had worked arsenic a librarian for USC for 10 years erstwhile she learned astir a occupation opening astatine a antithetic Southern California observatory: Mt. Wilson, adjacent Pasadena, tally by the Carnegie Institution of Washington. The role: collecting information and operating the 60-inch telescope.

Mueller had begun exploring astronomy by taking a four-week evening people astatine Griffith Observatory. Drawn to cognize more, she continued taking classes astatine USC and Rio Hondo College. As Mueller’s astronomy assemblage grew, her person Howard Lanning, an astronomer and scope operator, encouraged her to use for a presumption astatine Mt. Wilson Observatory.

“That was astir apt erstwhile my beingness changed,” Mueller said. “It had ne'er occurred to maine to permission my room occupation and prosecute astronomy. I didn’t person an astronomy degree; I had conscionable taken a fistful of classes.”

Jean Mueller sits successful beforehand of the power sheet of the 200-inch Hale Telescope astatine the Palomar Observatory.

(Kajsa Peffer)

For arsenic agelong arsenic she tin recall, Mueller has loved the stars. She remembers 1 circumstantial time successful 1958, erstwhile she was conscionable 8 years old:

“My member and I were jumping connected the bed, and helium told maine Halley’s Comet would beryllium disposable successful 1985.”

Mueller was calved successful an epoch erstwhile large probe telescopes passim the state inactive excluded women. Since the aboriginal 1900s, though the Carnegie Institution employed women arsenic “computers,” with fewer exceptions, they were not permitted to usage its telescopes. Both Mt. Wilson and Palomar had named their astronomers’ quarters “The Monastery,” antheral retreats wherever women were barred from technological conversations. The male-only lodging aboriginal became a justification to routinely contradict women entree to these telescopes.

By the 1950s, women were lone opening to flooded sex barriers to summation entree to the telescopes astatine the Mt. Wilson and Palomar observatories. From Margaret Burbidge to Vera Rubin to Nobel Prize victor Andrea Ghez, pioneering women astronomers built an intergenerational bequest of probe and discoveries astatine Palomar that would alteration knowing of the beingness forever.

As the archetypal pistillate scope relation connected Palomar, Mueller supported their work, and generations of astronomers. With the expertise and method grooming she gained connected Palomar, she besides began to marque her ain discoveries.

When Mueller was offered the Mt. Wilson job, she initially disquieted astir the fiscal hazard of changing careers and leaving 10 years of erstwhile acquisition astatine USC. But during this time, she chanced to be a lecture by writer Ray Bradbury.

Mueller inactive remembers the words that led her to instrumentality the leap into astronomy. “Whatever you do,” Bradbury advised, “be definite it makes you happy.”

After operating the 60-inch scope connected Mt. Wilson for 2 and a fractional years and becoming the archetypal pistillate to run the observatory’s 100-inch Hooker Telescope, Mueller interviewed for a caller occupation astatine Palomar. In 1985, she became the relation for the Samuel Oschin 48-inch telescope, making her the archetypal pistillate scope relation astatine the Palomar Observatory. She would enactment for 29 years.

“During her archetypal twelvemonth astatine Palomar, Mueller worked with Caltech unit astronomer Charles Kowal, who had successfully searched for star strategy objects and supernovae. An adept successful taking images and scanning the fragile 14-by-14-inch plates that captured information from Palomar’s telescopes during those years, Kowal taught Mueller captious techniques successful the analyzable process.

“Charlie Kowal was the archetypal idiosyncratic to archer maine that transient objects similar comets and asteroids needed to beryllium identified successful a timely manner,” Mueller said. She besides learned from Alain J. Maury, a French photographic idiosyncratic for the Palomar Observatory Second Sky Survey (POSSII), who taught her astrometry techniques to grounds the determination of celestial objects.

With the encouragement of Kowal and Maury, Mueller began scanning POSSII’s plates, looking for comets, asteroids and supernovae. Scanning progressive moving the sheet by manus beneath a stationary eyepiece.

“There was thing unbelievably breathtaking astir discovering a caller comet successful the sky,” Mueller said. “A existent adrenaline rush.

Mueller learned to run each 3 ample telescopes connected Palomar: the 200-inch Hale Telescope, wherever she was the elder relation for 15 years; the 60-inch telescope, and the 48-inch Samuel Oschin Telescope.

Over the people of her observational career, Mueller made important discoveries of her own. Using the Samuel Oschin Telescope, she discovered 15 comets, 13 asteroids — 7 of which are near-Earth objects — and 107 supernovae.

And erstwhile Comet Halley appeared successful the skies successful December 1985, Mueller was operating the 200-inch scope connected Palomar. At the time, it was the astir almighty scope successful the world.