Author: Joseph Long

We had an all-Laird, all-Hα night. With everything working so well, the most exciting thing going on instrument-wise was the initial setup, which I was able to get in on.

From our control workstation, I dutifully applied the “F-test” (which displays the letter “R”, for reasons lost to history), applied the “J-test” (works as advertised), performed the 253-click process to satisfy the prerequisites for the automated alignment loop, and then performed the other remaining steps when the automated alignment loop ran away. (“Apparently it’s shy and only works when it’s just me and the instrument” — Jared)

Then, we went to look at a star, and instead found two!

Visible near α Eri at almost 12 o’clock, the companion (star, not planet) lies at about 0.25″ separation. Without an adaptive optics system and a decent-sized telescope, you’d have a hard time seeing it at all. With the AO correction, we get diffraction rings around the stars in the scene. That means we can’t get any sharper—or resolve any more details—without a bigger telescope.

Speaking of binaries, we also imaged Mira (ο Ceti), a red giant star with a companion star.

Hmm, one star has a nice core and diffraction ring, but Mira (in the center) does not look as sharp. Why does the scene look so different from the first binary? Baby, don’t you go over-analyze. No need to theorize; I can put your doubts to rest.

Mira is 400x size of the sun but approximately the same mass. So, a big puffball. But the reason for the fuzzy image is not (just) that the star is a puffball. It has to be a nearby puffball for our system to resolve it. We can actually measure half a dozen pixels across the star, though our choice of filter and telescope means that’s only two “resolution elements”. (That’s just physics saying you can use as many pixels as you like but you ain’t getting any more information.)

I regret to inform you that on this night, there were no viscacha observations recorded. But worry not, gentle reader: many graduate students have gone on to have perfectly good careers using only archival viscacha data.

So, instead, I’ll share some computer stuff.

(Yeah, I know, I know. Just shut your eyes and scroll really fast to get to the song.)

It’s not entirely new this run, but I’ve been doing some shaking-out of the data pipeline feeding our dashboards (among other things). This is what a “normal” night looks like: most of the time we’re open, we’re saving data (that’s the “observing” row on the Observations chart). Since it’s a Laird night, it’s all Hα imaging, and everything’s colored red for our filters and beamsplitters.

Before an astronomer takes exception to me calling this a “normal” night when the seeing was hovering around 0.75 arcseconds, I should clarify that ≤0.5″ nights are the only ones worth seeing, the only place worth being.

Song of the Day

Bonus Literary Interlude

—No multipliques los misterios —le dijo—. Estos deben ser simples.
Recuerda la carta robada de Poe, recuerda el cuarto cerrado de Zangwill.

—O complejos —replicó Dunraven—.
Recuerda el universo.

“Abenjacán el Bojarí, muerto en su laberinto” by Jorge Luis Borges (1949)

In English:

“Don’t go on multiplying the mysteries,” he said. “They
should be kept simple. Bear in mind Poe’s purloined letter,
bear in mind Zangwill’s locked room.”

“Or made complex,” replied Dunraven. “Bear in mind
the universe.”

“Ibn Hakkan al-Bokhari, Dead in His Labyrinth” by Jorge Luis Borges (1949)

Well, folks, it’s been a few days but the content you crave is here. That’s right: viscacha photos! Just scroll past all this boring stuff.

Today was a sort of sneak preview of install day. MagAO-X exists as two separate and arguably equally important halves, the electronics rack and the optical table. We eventually need both halves on the platform. However, they must be sundered in two for transport, as they are connected only by a delicate umbilical of electronic cables.

We have started staging the main part of the instrument at the summit in the auxiliary building, which saves a fair bit of time on our install day. This means cables are coming off the day before.

As always, the most delicate part of the operation is the disconnection of the hand-soldered ribbon cables that carry commands to our MEMS deformable mirrors. Eden, Parker, and Katie carried out this fiddly task (along with removing many other, less fiddly, cables).

Once the cables were disconnected and secured, MagAO-X had to be wrapped for transport. I always think it looks like a foil-wrapped burrito.

The burrito had to be lifted off its legs, which we did with the help of the staff here at LCO (and a big honking crane).

The legs are a little adaptive acoustics system of their own, which can remove vibrations transmitted from the ground before they mess up our images. The legs get a separate ride, while the main part of MagAO-X rides up to the telescope on its little cart. Which is in turn on a truck.

I cannot be sure, but I believe the above image was the result of Katie Twitchell imagining a world in which the active leveling system was able to keep the orientation of MagAO-X constant despite going uphill.

Alas, the electronics rack is now lonely. It stays in the cleanroom overnight to be available for last-minute software work before we move it to the summit for installation on the platform.

Fortunately, I was there to keep it company.

Literary Interlude

I have chosen the option to embed a quotation rather than lyrics from the Song of the Day (as per blog rules for 2024B). Many of us spent good chunks of this day in the library at Las Campanas trying to finish other related work in the lulls between major operations.

This quote from “The Library of Babel” seems relevant to exoplanet direct detection in general:

Visiblemente, nadie espera descubrir nada.

A la desaforada esperanza, sucedió, como es natural, una depresión excesiva.

For the obligate Anglophones:

Obviously, nobody expects to discover anything.

Naturally, this inordinate hope was followed by a profound depression.

Jorge Luis Borges is one of the quintessential magical realist writers, and “The Library of Babel” is one of my favorite short stories about … libraries, (in)finity, combinatorics, information theory, and perhaps cosmology? You should go read it (or en Español, si quieras).

Viscachas

The viscachas have been harder to spot this run, but we got a bumper crop today courtesy Laird and Parker, with five confirmed viscacha sightings.

Song of the Day

Today’s song of the day is unrelated.