Fireflies and Binary Stars

Flicker, firefly - orbit, alight - constellations

Fireflies at Linggu Temple, China (Wikimedia Commons)

Flicker, firefly

Fireflies are a family of soft-bodied beetles. Altogether, this family includes over 2,000 species. The fire in their bellies¹ comes from specialized organs that produce a type of chemical generically called luciferin. That luciferin is processed by an enzyme (a luciferase) into 1,2-dioxetanone, an unstable molecule that gets rid of excess energy by… producing light². That light is usually yellow or green, with a few species twinkling a pale red.

Originally, the fireflies’ fire was a larval warning signal, “Do not eat me, I taste bad!” Later, in many (but not all) species, evolution co-opted this signal for adult mate recognition, “Kiss me, I’m tasty.” Of course, signals can be misused. In a real-life biological illustration of catfishing, the femme fatales of one firefly species ‘fake it’ by using the signal of another species to attract males of that species... and eat them. Women, right?

Some people in your life will be fireflies; brief, intense flashes that leave an outsized impact despite the brevity of their visit.

The femme or homme fatale that swoops you into a short, steamy romance. The grandparent who passes away too soon and inhabits only a few salient memories. The substitute teacher who kindles the interests that set your career path. The simple rejection that breaks you so profoundly that it will take years to recover. The childhood soulmate who moved away. The stranger who offered a helping hand just when you needed it.

The lifespan of firefly species differs, but they generally only spend a few months as adults. Then, their flickers fade to make way for the new generation.

But we are not done.

Aim your hungry eyes skyward. Look beyond the trees, pierce the clouds with your gaze, and turn the lights down low. There they are, the fireflies of the cosmos — stars, also flickering, only on a different timescale. Nest and nestle with the firefly that found you, even if only for one fated night. Embrace and orbit each other’s desires for a while.

Like binary stars.

Orbit, alight

In 1650, Italian astronomer Giovanni Battista Riccioli looked at the Big Dipper through an early telescope and he noticed something peculiar. The star Mizar, the kink in the Dipper’s handle, was not one star, but two. Better telescopes have since shown that Mizar is actually a double double star — a quadruple star system of two binary stars.

Binary stars are two stars that are gravitationally bound and orbit each other.

Some people in your life are intense and ephemeral fireflies, others are binary stars that draw you into a long-term orbit.

The sibling that shapes your childhood and adolescence. The co-founder of your business. The potential love interest who never quite worked out that way and yet stays a part of your life as a kindred spirit. The best friend who co-wrote your fumbles and all the firsts during growing up. The mentor who gently helped you through your initial stumbling steps into adulthood and remained a guiding presence.

(Wikimedia Commons, Merikanto)

Binary stars, though generally stable, inevitably evolve.

Once one (or both) of the stars swell(s) beyond the so-called Roche lobe, the heavenly bodies exchange materials. Sometimes you are sucked dry by your binary star partner, sometimes they give much without expecting anything in return. Binary star systems can also be destabilized by an external influence, after which the partners continue solo.

The future of a binary star system depends on several factors — the mass of the stars, their proximity to one another, and the stages in their lifetimes. They can evolve into a pair of white dwarfs, neutron stars, black holes, or go supernova.

In some cases, though, the partners of a binary star system merge into a larger, more luminous star. If the conditions and the two partners are just right, a binary star merger might plant the seeds for a type of planet called a hot Jupiter.

Come closer, the night is getting cold and I want to show you the treasures in the dark, because we are still not done, my star. Look at the cosmic fireflies with me. See how they play so eagerly into our human predisposition to see patterns. Let’s make up our own constellations, woven by the connections we make.

Constellations

Every object with mass - fireflies, stars, people - is affected by gravity. It’s (by far) the weakest of the fundamental forces, but it is relentless and pervades everything. Gravity shapes star systems and bends light.

It shapes life too.

Take a potted plant and put it on its side. The roots will turn downward, the stem upward. This response to gravity is called gravitropism. Roots have positive gravitropism (in the direction of the gravitational pull, aka ‘down’) and stems negative gravitropism (away from the pull, or ‘up’). Like life shaped by gravity, we are drawn to some people and pushed away by others. As a result of this push and pull, we form constellations — through flickering signals and shared orbits, lucky stars find companions.

Carl Sagan once wrote,

The nitrogen in our DNA, the calcium in our teeth, the iron in our blood, the carbon in our apple pies were made in the interiors of collapsing stars. We are made of star stuff.

Here we end today’s story of jumbled metaphors, stuck between stars and fireflies, sometimes one, sometimes the other. Sometimes a flash in the night, sometimes a close orbit that lasts lifetimes, and sometimes a cosmic merger that sends ripples through the gravitational field.

In all cases, each firefly, each star, each one of us, is a node in a constellation. Even rogue stars that hurtle through intergalactic space alone do not escape gravity’s fractal web of infinite connection; a spiderweb in space speckled with glittering morning dew.

When the fireflies have gone to sleep.

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Thanks for flickering with me. Click buttons to send me an extra flash 🌟

1. In all species, larvae produce light. Only in some species, adults do too.

2. And it’s very efficient light production. Firefly light is so-called cold light, which doesn’t lose energy by ‘leaking’ into ultraviolet or infrared. Inspired by fireflies, we might even make LEDs >50% more efficient, which could save a lot of energy.