CELEBRATE: WOMEN'S HISTORY MONTH

If you’ve spent much time stargazing, you may have noticed that while most stars look white, some are reddish or bluish. Their colors are more than just pretty – they tell us how hot the stars are. Studying their light in greater detail can tell us even more about what they’re like, including whether they have planets. Two women, Williamina Fleming and Annie Jump Cannon, created the system for classifying stars that we use today, and we’re building on their work to map out the universe.

By splitting starlight into spectra – detailed color patterns that often feature lots of dark lines – using a prism, astronomers can figure out a star’s temperature, how long it will burn, how massive it is, and even how big its habitable zone is. Our Sun’s spectrum looks like this:

Astronomers use spectra to categorize stars. Starting at the hottest and most massive, the star classes are O, B, A, F, G (like our Sun), K, M. Sounds like cosmic alphabet soup! But the letters aren’t just random – they largely stem from the work of two famous female astronomers.

Williamina Fleming, who worked as one of the famous “human computers” at the Harvard College Observatory starting in 1879, came up with a way to classify stars into 17 different types (categorized alphabetically A-Q) based on how strong the dark lines in their spectra were. She eventually classified more than 10,000 stars and discovered hundreds of cosmic objects!

That was back before they knew what caused the dark lines in spectra. Soon astronomers discovered that they’re linked to a star’s temperature. Using this newfound knowledge, Annie Jump Cannon – one of Fleming’s protégés – rearranged and simplified stellar classification to include just seven categories (O, B, A, F, G, K, M), ordered from highest to lowest temperature. She also classified more than 350,000 stars!

Type O stars are both the hottest and most massive in the new classification system. These giants can be a thousand times bigger than the Sun! Their lifespans are also around 1,000 times shorter than our Sun’s. They burn through their fuel so fast that they only live for around 10 million years. That’s part of the reason they only make up a tiny fraction of all the stars in the galaxy – they don’t stick around for very long.

As we move down the list from O to M, stars become progressively smaller, cooler, redder, and more common. Their habitable zones also shrink because the stars aren’t putting out as much energy. The plus side is that the tiniest stars can live for a really long time – around 100 billion years – because they burn through their fuel so slowly.

Astronomers can also learn about exoplanets – worlds that orbit other stars – by studying starlight. When a planet crosses in front of its host star, different kinds of molecules in the planet’s atmosphere absorb certain wavelengths of light.

By spreading the star’s light into a spectrum, astronomers can see which wavelengths have been absorbed to determine the exoplanet atmosphere’s chemical makeup. Our James Webb Space Telescope will use this method to try to find and study atmospheres around Earth-sized exoplanets – something that has never been done before.

Our upcoming Nancy Grace Roman Space Telescope will study the spectra from entire galaxies to build a 3D map of the cosmos. As light travels through our expanding universe, it stretches and its spectral lines shift toward longer, redder wavelengths. The longer light travels before reaching us, the redder it becomes. Roman will be able to see so far back that we could glimpse some of the first stars and galaxies that ever formed.

Learn more about how Roman will study the cosmos in our other posts:

Roman’s Family Portrait of Millions of Galaxies

New Rose-Colored Glasses for Roman

How Gravity Warps Light

1. Access or share healing resources for Black Queer and Trans communities.

2. Learn about trans history or tips for allies of trans people

3. Find a local TDOV event & join in!

happy Trans Day of Visibility!

Today in Black Excellence: Maya Angelou—a literature titan whose 1969 memoir was the first nonfiction bestseller by an African American woman.

“There is no greater agony than bearing an untold story inside you.” —Maya Angelou, I Know Why the Caged Bird Sings.

What was the early life of Maya Angelou?

She became a celebrated writer and Black icon, but it came from a childhood of tragedy. Born on April 4, 1928, in St. Louis, Missouri, Angelou was quickly exposed to racism as a child. Her parents split when she was young, and while visiting her mother, aged eight, she was raped by her mother’s boyfriend: her uncles killed the boyfriend in revenge. These horrors left Angelou mute for five years, as she discussed in an interview with Oprah, a close friend. At age 16, she gave birth and was forced to work grueling jobs to support her son—including fry cook, sex worker, and nightclub performer.

She recounted her traumas to close friend James Baldwin—fellow writer and Black icon. He challenged Angelou to write about her experiences, and she published the wildly successful memoir I Know Why the Caged Bird Sings. It catapulted Angelou to international stardom and was nominated for a National Book Award in 1970. It remained on The New York Times’ paperback nonfiction bestseller list for two years—the longest record in history.

What made her such a Black icon?

Angelou was a close friend of Martin Luther King Jr., who was assassinated on her birthday in 1968. Angelou stopped celebrating her birthday for years afterward. In 1964, Angelou helped another activist friend Malcolm X in founding the Organization of Afro-American Unity.

Spanning over 50 years, she published seven autobiographies, three books of essays, books of poetry, and plays. Her 1971 poetry collection, Just Give Me a Cool Drink of Water ’Fore I Die, was nominated for the Pulitzer Prize. Because of her tireless work in literature and political activism, Angelou became widely respected as a spokesperson for the Black experience, particularly of women. You can even find her legacy in your pocket—she recently became the first black woman to appear on a US quarter.

Original portrait by Tumblr Creatr @inuqo

"I was filled with such deep gratitude while working on this illustration of Maya Angelou. Her talent, creativity, strength, power and resilience is inspiring to us all and I wanted to display how beautiful her Universe was. How important her words and life's journey was because it showed us that no matter how hard we fall, still we can rise".”

Sayyida al Hurra (1485-1561), was a queen of Tétouan in 1515-1542 and a pirate queen in the early 16th century. She is considered to be “one of the most important female figures of the Islamic West in the modern age”.

Pari Khan Khanum (1524-1576) was a Safavid princess. An influential figure in the Safavid state, Pari Khan Khanum was well educated and knowledgeable in traditional Islamic sciences such as jurisprudence, and was an accomplished poet.

Kösem Sultan (1589-1651) was one of the most powerful women in Ottoman history. She was one of the prominent figures during the Sultanate of Women.

Umm Kulthum (1898/1904-1975)  was an internationally renowned Egyptian singer, songwriter, and film actress active from the 1920s to the 1970s.  She was known for her extraordinary vocal ability and style, and she was one of the greatest and most influential singers of the 20th century. Umm Kulthum is considered a national icon in her native Egypt and is dubbed as The voice of Egypt and Egypt’s fourth pyramid. Umm Kulthum remains as the most revered legendary Arab singer.

Sabiha Gökçen (1913-2001) was the first Turkish combat pilot and possibly the world’s first fighter pilot.

Meena Keshwar Kamal (1956-1987)  was an Afghan revolutionary political activist, feminist, women’s rights activist and founder of Revolutionary Association of the Women of Afghanistan (RAWA), who was assassinated in 1987.

Betty Shabazz (1934-1997) was an American educator and civil rights advocate.

A day for celebrating the Muslim women in your life!

“It is an artist's duty to reflect the times.” - Nina Simone

Billie Holiday (1915-1959)

Nina Simone (1933-2003)

Tina Turner (1939- )

Aretha Franklin (1942-2018)

Diana Ross (1944- )

Grace Jones (1948- )

Whitney Houston (1963-2012)

Janet Jackson (1966-)

Missy Elliott (1971- )

🍀EMPATHS ONLY☘️

Samus Aran is a Feminist Icon that sadly a lot of people overlook, she helped bring a lot of positive change to women everywhere!