Édmée Chandon, French astronomer

Edmée Chandon, born on 21 November 1885 in the 11th arrondissement of Paris and died on 8 March 1944 in the 14th arrondissement of Paris, was a French astronomer. On March 1, 1912, she became the first professional woman astronomer working in France at the Paris Observatory. She was also the first French woman to obtain a doctorate in mathematical sciences in March 1930.

French astronomer Edmée Chandon (1885-1944) (PD-US)

Nicole-Reine Lepaute, French calculator and astronomer

Nicole-Reine Lepaute, born Étable on 5 January 1723 in Paris, died in the same city on 6 December 1788, was a French calculator and astronomer. Together with Caroline Herschel and the Marquise du Châtelet, she was one of the leading women scientists of the Age of Enlightenment.

Her work is often included in that of other authors, including Jérôme de Lalande and her husband. But, if we are to believe Lalande, who loved her very much, she was “a master rather than an emulator “. In particular, she helped to calculate the precise date of the return of Halley’s Comet of 1759 and was a major contributor to the calculation of the astronomical ephemeris Knowledge of Time.

Portrait of Nicole-Reine Lepaute (CC BY-SA 4.0)

Once, most famous scientists were men. But that’s changing.

Women still are underrepresented in STEM fields. But some female scientists are now gaining recognition—and due credit—for their breakthroughs.

National Geographic
Science | Women of Impact

By Angela Saini

“I have something to tell you.”

I was ready to head home after giving a lecture about Inferior—my book documenting the history of sexism in science and its repercussions today—when a soft-spoken woman approached me. She told me she was studying for a Ph.D. in computer science at a British university and was the only woman in her group. Her supervisor wouldn’t stop making sexist jokes. He never picked her for workshops or conferences.

“Every interaction is awkward for me. I feel intimidated,” she said. “Most of the time I just find myself counting every minute.” Her plan was to see out the final years of her Ph.D., leave the university, and never look back.

I’ve had hundreds of these fleeting encounters with women scientists and engineers, all over the world, in the two years since publication of the book—which seems to reflect back at women the kinds of sexism that they experience in their own lives. When these women approach me at events to quietly share their stories, I’ve found what they want above all is empathy, to be told they aren’t imagining their misery. Their accounts of discrimination, marginalization, harassment, and abuse reinforce that, though progress has been made, there’s a long way to go.

7 women scientists who changed the world

National Geographic pays tribute to seven women scientists who, through their discoveries, have changed the world.
Juliette Heuzebroc, Romy Roynard

“Women scientists” sounded like a sweet oxymoron to the ears of a largely male-dominated research community. Many of them were shunned by the awards or had their discoveries stolen because they were women.
For centuries, female researchers had to “volunteer” to assist members of science faculties, and their major discoveries were attributed to their male colleagues and their names were removed from experimental protocols.
They often had to fight for even the “natural recognition given to their husbands or colleagues,” says Anne Lincoln, a sociologist at Texas Methodist University who has studied the barriers to women in the history of science.
According to a study conducted in 2014, women are still under-represented in science: only a third of researchers are women. Yet many women scientists have participated in discoveries that have changed our world.
On International Women’s Rights Day, National Geographic is honoring seven women scientists who have made major discoveries without always receiving the credit they deserve, simply because they were born women.


© marie crayon / national geographic

Born in 1868 in Massachusetts, Henrietta Swan Leavitt is an American astronomer. In 1893, she was recruited at the Harvard University Observatory to join “Harvard Computers”, a group of women hired to establish mathematical processing of astronomical data; women were not allowed to use telescopes at the time. Henrietta Leavitt was responsible for examining photographic plates taken at different periods in order to measure and classify the brightness of stars.
In 1908 and 1912, she published the results of her work on the Magellanic Clouds, a group of dwarf galaxies. Her observations enabled her to detect the periodic variation in the luminosity of certain stars, the cepheids. She thus established the period-luminosity ratio, known as Leavitt’s Law, which has enabled astronomers to develop a system for calculating distances in the universe and thus measure the distance between our planet and other galaxies.
Henrietta Leavitt was appointed head of the Department of Stellar Photometry at Harvard Observatory in 1921, a few months before her death.
Gösta Mittag-Leffler, a Swedish mathematician, attempted to nominate her for the Nobel Prize in Physics in 1926. He was unsuccessful, as the prize could not be awarded posthumously. But an asteroid and a lunar crater were named Leavitt in honour of the astronomer.

Inner Telescope, a Space Artwork by Eduardo Kac

Conceived to exist in weightlessness by the artist Eduardo Kac and created on board the International Space Station by the French astronaut Thomas Pesquet, the work “Indoor Telescope” is the first milestone in a new form of artistic and poetic creation, freed from the constraints of gravity. The film “Indoor Telescope, a Space Work by Eduardo Kac”, takes us on an artistic and scientific adventure, from the conception of the work in Eduardo Kac’s studio in Chicago, to its realisation in orbit 400 km from Earth, during the Proxima mission of the European Space Agency.

With Eduardo Kac, Thomas Pesquet, Gérard Azoulay, Hugues Marchal and Thierry Duquesne. Directed by Virgile Novarina. Produced by the CNES Space Observatory, with the support of ESA and the Daniel and NinaCarasso Foundation.

The meridian sighting marks of the Neuchâtel Observatory

Article on the website of Swisstopo

To determine Swiss time the Neuchâtel Observatory observed the passage of the stars above the meridian using a telescope. To make sure that the telescope was correctly adjusted, it was required to scan the north-south axis and identify two marks serving as reference points. These marks still exist today. The southern mark in Portalban has a direct link to swisstopo since it was integrated into the national survey network.

Sighting mark in Portalban (left), sighting mark in Chaumont (right)

What is a meridian sighting mark?

It is a stone construction which had to be visible with the meridian telescope. In order to enable the Neuchâtel Observatory to cover the north-south axis and thus determine the time at which the stars pass over the meridian, two telescopes had to be built. One to the north and the other to the south. If the telescope did not detect these marks, they had to be readjusted.

In 1959, the lack of precision of the meridian telescope and the arrival of atomic clocks sounded the death knell for the use of sighting marks. However, they are now part of the heritage of the Neuchâtel Observatory and swisstopo.

Where are these marks?

The Observatory of Neuchâtel had three sighting marks built. The closest was on the Mail hill, 80 meters from the Observatory. It no longer exists today. The northern sighting mark was erected in Chaumont, 3 kilometres from the Observatory. The third was built in Portalban, on the shores of Lake Neuchâtel, 9.5 kilometres south of the Observatory. Like the mark in Chaumont, the Portalban sighting mark still exists

The southern sighting mark in Portalban

The first mark in Portalban was rather crude. Indeed, in 1861, the Observatory had a black diamond painted on a rock on a white background. The second version of the mark was also created in 1861 and consisted of an obelisk 3.10 meters high. A white diamond surrounded by black was also painted on the stone structure.

In 1927, the Portalban sighting mark was integrated as a first-order fixed triangulation point and as a third-order triangulation point by the Federal Topographic Service (swisstopo). This fixed point was therefore measured precisely, and its coordinates are well known. As a result, the point is protected by federal law and cannot be dismantled. In 1886, a levelling pin was sealed on the sighting mark. swisstopo is responsible for its inspection and renovation. And its condition is checked every 12 years.  

Portalban, in the line of sight of the Neuchâtel Observatory

The association “EspaceTemps”, which wants to safeguard the scientific heritage of the former Neuchâtel Observatory, inaugurated the renovated Portalban calibration sight this afternoon. For the Federal Office of Topography swisstopo, it is a 1st category marker of the national triangulation, for drawing up the map of the country. But let’s go back to 1861, when this calibration sight had another function…

Report on the television channel CanalAlpha (in French)

Calibration sight of Portalban to calibrate the meridian telescope of the Neuchâtel Observatory. It was renovated during the year 2020 by the EspaceTemps Association.