iiinova — where your digital self keeps evolving

Replies

Robert "The Bobby Yaga" McNees @mcnees.bsky.social · 06/10/2025

VAR! In the early morning hours #OTD in 1923, Edwin Hubble took a photo plate of M31 that showed a Cepheid variable star. Using Henrietta Swan Leavitt’s distance-luminosity relationship, Hubble concluded that M31 is another galaxy outside the Milky Way. 🧪 🔭 ⚛️ Image: Carnegie Observatories

Photo plate of Hubble's famous "VAR!" discovery. This is a photonegative plate of an image of the Andromeda Galaxy, with several small annotations made in grease pencil. One of them was previously marked "N" for "nova," but the N has been crossed out and replaced with an excited "VAR!" to indicate a Cepheid Variable.

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profradii.bsky.social @profradii.bsky.social · 06/10/2025

Two giants.

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Michael Zaharis @michaelzaharis1.bsky.social · 07/10/2025

Was this taken at the Mt. Wilson 100" telescope? I visited it a couple years back - it was very moving to see the telescope that, maybe more than any other since Galileo's first crude one, told us of our place in the universe.

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Atonal Apples @rgc1732.bsky.social · 06/10/2025

Leavitt is one of my heroes, so much so that I named my cat Henrietta.

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Robert "The Bobby Yaga" McNees @mcnees.bsky.social · 06/10/2025

You can see three marks "N" on the plate where Hubble had identified novae. Comparing with a plate taken the night before, he realized the brightness of one of them was changing. Recognizing a Cepheid, he crossed out the "N" and excitedly wrote ‘VAR!’ (2/n)

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