How long to image the M59 with the Vaonis Vespera Pro 2

From a Bortle 6 suburban sky, the Vaonis Vespera Pro 2 needs about 1 h 42 min (613 subs of 10 s) for a solid image of the M59. A quick look takes 26 min; a showpiece 6 h 48 min. Under a Bortle 3 rural sky the solid figure drops to 48 min. At Bortle 6 the limit is skyglow, so a darker site or a filter helps more than longer subs. In this scope's field it fills 5% of the frame’s short side.

M59 with the Vaonis Vespera Pro 2: 10 s subs.
SkyQuick lookTarget obvious, still noisySolidClean enough to shareShowpieceSmooth faint detail, print-worthy
Bortle 1Excellent dark site11 min65 subs43 min257 subs2 h 51 min1,027 subs
Bortle 2Typical dark site11 min67 subs45 min268 subs2 h 58 min1,071 subs
Bortle 3Rural12 min73 subs48 min289 subs3 h 12 min1,153 subs
Bortle 4Rural / suburban transition14 min85 subs56 min339 subs3 h 46 min1,354 subs
Bortle 5Suburban17 min105 subs1 h 10 min418 subs4 h 38 min1,671 subs
Bortle 6Bright suburban26 min154 subs1 h 42 min613 subs6 h 48 min2,451 subs
Bortle 7Suburban / urban transition41 min246 subs2 h 44 min984 subs11 h3,935 subs
Bortle 8City1 h 05 min391 subs4 h 20 min1,561 subs17 h6,241 subs
Bortle 9Inner city1 h 56 min698 subs7 h 45 min2,790 subs31 h11,158 subs

Adjust in the calculator

Power and kit for this session

Allowing for slewing, focusing and rejected subs, that is about 2 h 13 min of run time. The Vespera Pro 2’s battery (rated about 11 h) should cover it; a power bank still keeps the phone running the app alive. (Bortle 6, solid image; we allow 30% over the integration time.)

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How it frames

The M59 is 5′ × 3.5′ across. The Vespera Pro 2 frames 1.65° × 1.65° at 1.68″ per pixel, so it fills 5% of the frame’s short side.

Longer subs

10 s subs by default; Expert Mode manual targets allow 1 to 30 s. Alt-azimuth only; CovalENS mosaic gives 3.2° × 3.2° at 50 MP. Time for a solid image by sub length:

Sub lengthBortle 3Bortle 5Bortle 7
10 s48 min289 subs1 h 10 min418 subs2 h 44 min984 subs
20 s41 min125 subs1 h 03 min190 subs2 h 37 min473 subs
30 s39 min79 subs1 h 01 min122 subs2 h 35 min311 subs

About the M59

An elliptical galaxy in Virgo, close to M60. A smudge, but a bright one.

NGC 4621 · Galaxy in Virgo · magnitude 9.6 · 5′ × 3.5′ · best in Mar, Apr, May. Reachable from mid-northern latitudes (UK, northern US, central Europe) and from the south.

Galaxies are broadband targets: their light is mostly starlight spread across the spectrum, so a dual-band filter throws most of it away and makes things slower, not faster. Shoot without a filter (or with a plain UV/IR cut) and rely on total time and a dark sky. The core of a galaxy is usually many times brighter than its outer disc, so a short stack shows the nucleus long before the arms; the figures here are for the arms and disc, not the core.

Field rotation in Alt-Az mode crops the edges of the stack over a long session, so on a big galaxy re-centre now and then or use EQ mode where your scope supports it.

About the Vaonis Vespera Pro 2

The square-sensor 2026 Vespera with 2 µm pixels. Sharper than the Vespera 3 on small targets and correspondingly slower per pixel; the 12.5 MP square frame suits galaxies and planetaries.

10 s subs by default; Expert Mode manual targets allow 1 to 30 s. Alt-azimuth only; CovalENS mosaic gives 3.2° × 3.2° at 50 MP. Optional clip-on Vaonis filters: dual-band, light-pollution (CLS) and solar.

Longer subs matter most under dark skies, where read noise rather than skyglow sets the floor. From a city the difference between 10 s and 30 s subs is small; from a rural site it can halve the total time, especially with a dual-band filter in place.

Stack across nights. Every smart scope app can continue a stack or you can combine the saved frames on a computer; the figures here are totals, not single-session limits.

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Imaged the M59 with your Vespera Pro 2? Did the solid figure match?Anonymous, one tap. It is how the model gets calibrated.

Have an image of the M59 from a Vespera Pro 2? Email it with your total time and sky to [email protected] and it goes here, credited.

Same target, other telescopes

All telescopes for the M59 · All targets for the Vespera Pro 2