The original ZWO Seestar S50 smart telescope on its tripod, photographed from below against a clear blue daytime sky, its rounded optical tube raised above the Seestar-branded base, with treetops along the bottom edge of the frame.
Gear

Seestar S50 Pro vs the original S50: is the upgrade worth $999?

ZWO’s Seestar S50 Pro started shipping on September 1 and now lists at $999 (€999 in Europe) on ZWO’s product page, after an $899 launch price that ended on September 15. I’ve run the original S50 from my Bortle 7 balcony in Nicosia for most of a year, so the question I care about is narrow: if you already own an S50, what does $999 buy you? It buys the same light grasp and the same pixel scale, roughly 3.7 times the sky per frame, a 67% bigger battery, a wide-angle camera, and a main sensor nobody expected. For most S50 owners imaging from a city, I’d hold off. For a few, it fixes the exact thing that’s been annoying them. ...

October 1, 2026 · 9 min · Andreas Ioannou
Neptune imaged by NASA's Voyager 2 in 1989 — a deep-blue disc marked by the dark oval of the Great Dark Spot and streaks of white, high-altitude methane-ice cloud.
Celestial event

Neptune at opposition, September 26: how to find the most distant planet

Neptune reaches opposition in the small hours of September 26 (around 00–01 UT), which makes this the best week of the year to track down the solar system’s most distant planet. Opposition just means the planet sits opposite the Sun in our sky: it rises at sunset, climbs highest near local midnight, and stays up until dawn. It’s also as close and as bright as Neptune gets in 2026 — magnitude 7.8, about 28.9 AU away. That brightness still isn’t enough for your eyes alone. Magnitude 7.8 is roughly three times fainter than the dimmest star you can catch with the naked eye under a good sky, so this is a binocular-and-telescope target. What you’re hunting is a single blue-grey point among the faint stars of Pisces, and the whole game is telling it apart from them. ...

September 25, 2026 · 6 min · Andreas Ioannou
Saturn imaged by the Hubble Space Telescope with its rings turned nearly edge-on, appearing as a thin bright line across the planet's disc, with two of its moons as bright points at upper left.
Gear

How much telescope do you need to see Saturn's rings?

Saturn reaches opposition on October 4, 2026, which is the best night of the year to point anything at it. Around that date the planet sits opposite the Sun in our sky: closest to Earth for the year, brightest for the year at about magnitude 0.3 (apparent), and above the horizon all night. The question I get every autumn is how much telescope you need to actually see the rings. The answer depends entirely on what you mean by “see.” ...

September 21, 2026 · 7 min · Andreas Ioannou
The tilted spiral galaxy NGC 7331 with a golden central bulge, blue-white spiral arms and dark dust lanes, three smaller background galaxies scattered across the star field above it
Celestial event

SN 2026aaiv: a Type Ia supernova is brightening in NGC 7331, and how to see it

A white dwarf in the galaxy NGC 7331 tore itself apart in a thermonuclear explosion, and the light is only now reaching us, bright enough to catch in a backyard telescope. SN 2026aaiv is a Type Ia supernova in a spiral galaxy in Pegasus, about 44 million light-years away, and it’s still brightening. The ATLAS survey flagged it on September 1; by September 11 it had climbed to roughly magnitude 13.8, and observers expect a peak near 11th to 12th magnitude within a week or two. Pegasus rides almost overhead from 35°N around midnight this month, so from Cyprus the timing and the geometry both line up. If you own a telescope or a smart scope, the next couple of weeks are the window. ...

September 12, 2026 · 8 min · Andreas Ioannou
The Andromeda Galaxy (M31), a bright oval spiral tilted almost edge-on with dark dust lanes crossing its glowing white core, surrounded by a dense field of foreground stars, with the small companion galaxies M32 and M110 nearby.
Gear

The Seestar S50 is discontinued — is 30 mm enough from a city balcony?

The ZWO Seestar S50 I reviewed in May is out of production. Walk into the smart-telescope aisle today and the Seestar you can actually buy new is a 30 mm scope: the S30 or the S30 Pro. The “successor” has 20 mm less aperture than the thing it replaced. If you’ve spent any time reading telescope forums, that sentence should make you flinch, because aperture is the one number those forums agree on. The question I keep getting emailed: does a 30 mm smart telescope give up too much from a light-polluted balcony, and should you hunt down a used S50 instead? ...

July 27, 2026 · 8 min · Andreas Ioannou
Partial Solar Eclipse in New Orleans
Gear

What solar filter to buy for the August 12 eclipse

The August 12 total solar eclipse is 55 days out. If you’re planning to photograph it, point a telescope at it, or just watch the partial phases safely, you need a solar filter. Prices are still normal and stock is still available. By late July neither will be true. Here’s what the numbers on the label mean, which filters are worth the money, and what I’m packing for Spain. The one number on every solar filter: optical density Every solar filter blocks a fraction of the Sun’s light. The spec you care about is optical density (OD), a logarithmic scale. OD 5 means only 10^-5 of the incoming light gets through — one hundred-thousandth. OD 4 passes ten times more. That factor of ten is the line between safe for your eyes and not. ...

June 18, 2026 · 7 min · Andreas Ioannou
Hubble image of globular cluster IC 4499 — thousands of resolved stars against deep space
Gear

The Seestar S50, six months in: what I'd tell a friend before they buy one

The ZWO Seestar S50 sat on my balcony railing in Nicosia for 47 sessions between November 2025 and April 2026. I pointed it at globulars, planetaries, galaxies, the Moon, and — twice — Jupiter. After six months I know exactly who should buy one and, more usefully, who should save the money for something else. The setup that kept me coming back The S50 weighs 1.5 kg. I carry it out with one hand, set it on the railing, open the app, and I’m imaging within three minutes. No polar alignment, no balance weights, no multi-star alignment routine. The internal plate solver — the same astrometry.net algorithm I wrote about last month — handles pointing. Tap an object, the telescope slews, stacking begins. ...

May 10, 2026 · 7 min · Andreas Ioannou
A wide-field amateur astrophotograph of the Corona Australis region, the kind of star field a smart telescope plate-solves in seconds
AI × astronomy

How plate solving works: the algorithm behind every smart telescope

Every time I tap a target on the Seestar app, my phone tells the telescope what to find, but not where it is. The S50 figures that part out itself: it slews in the rough direction, takes a calibration frame, asks “where on the sky was this taken?”, and adjusts. Three seconds, one re-pointing nudge, target centered. Plate solving is the answer to that one question: given an arbitrary image of stars, recover the pointing, scale, and rotation. The dominant open-source approach, astrometry.net, was published by Lang, Hogg, and collaborators in 2010 and has quietly become the unsung backbone of consumer astrophotography. Every smart telescope on the market today, from the Seestar S50 to the Vespera Pro, the DWARF 3, and the Celestron Origin, runs some variant of this in real time. ...

April 25, 2026 · 9 min · Andreas Ioannou