#photometry

And now for some more science, also from last night. This is a plot of brightness for the Delta Scuti variable star SZ Lyncis. These regular dips and peaks are a result of the star physically expanding and contracting in cycles of rhythmic pulsation, driven by changes in opacity in its chromosphere!

"Scientists first detected electrical “brain waves” a century ago, but seeing large-scale patterns of these neural oscillations has remained a challenge. Now, researchers have developed an optical technique for capturing these waves up to frequencies of roughly 100 Hz.

The technique, dubbed TEMPO (for “trans-membrane electrical measurements performed optically”), incorporates an optical-fiber sensor that can detect electrical activity in the brains of mice while they are awake and moving, rather than sedated (Cell, doi:10.1016/j.cell.2025.06.028). TEMPO also uses an optical “mesoscope,” an imaging device with a wide field of view and high spatial resolution. “This technology allows us to look at multiple brain areas at once and see the brain waves sweeping across the cortex with cell-type specificity,”(...)."

"The Stanford researchers say their illumination is roughly 10 times more stable than existing voltage-sensing photometry systems. This type of stability is key to picking up the signals from genetically encoded voltage indicators (GEVIs), or proteins that fluoresce in response to voltage differences across cell membranes."

6.7.18

It might seem silly to suggest that you can see a planet many hundreds of lightyears away orbiting another star from your own house with off-the-shelf equipment, but amateur astronomers like myself have been doing it for over a decade! How? Using the same method professionals do - specifically the transit method. Modern commercial CCD and CMOS cameras are sensitive enough to detect the minuscule change in brightness as an exoplanet passes between its parent star and us. And it is a tiny drop in brightness, between 10 and 20 parts per thousand for the largest of planets.

It's these large, close-in planets that are accessible to amateur astronomers, thanks to the relatively deep transits and fast orbits that are easily detectable and can be fully captured in a single night of imaging. This is one of my most recent observations of such a transit. The planet in question is TrES-1b, a world a little larger than Jupiter in a scorchingly-tight orbit that lasts just 3 days. Such planets are called hot Jupiters for obvious reasons. They are large, low-density volatile-rich worlds whose proximity to their star heats their atmospheres to many hundreds to thousands of degrees. In the case of TrES-1b, the average temperature was directly measured with the Spitzer infrared space telescope to be Over 786 °C.