How long should I image the Sombrero Galaxy with the eQuinox 2 from a Bortle 6 sky?

About 42 min of total integration for a solid image, or 2 h 47 min for a showpiece. A quick look takes 10 min.

How many subs is that on the eQuinox 2?

At the default 4 s sub length, 626 subs for a solid image from Bortle 6 and 376 from Bortle 3.

Does a dual-band filter help on the Sombrero Galaxy?

No. The Sombrero Galaxy is a broadband target and a dual-band filter blocks most of its light. Shoot without a filter.

How long to image the Sombrero Galaxy with the Unistellar eQuinox 2

From a Bortle 6 suburban sky, the Unistellar eQuinox 2 needs about 42 min (626 subs of 4 s) for a solid image of the Sombrero Galaxy. A quick look takes 10 min; a showpiece 2 h 47 min. Under a Bortle 3 rural sky the solid figure drops to 25 min. At Bortle 6 the limit is a mix of skyglow and read noise. In this scope's field it fills 26% of the frame’s short side.

Sombrero Galaxy with the Unistellar eQuinox 2: 4 s subs.
Sky	Quick lookTarget obvious, still noisy	SolidClean enough to share	ShowpieceSmooth faint detail, print-worthy
Bortle 1Excellent dark site	6 min88 subs	23 min351 subs	1 h 34 min1,403 subs
Bortle 2Typical dark site	6 min90 subs	24 min360 subs	1 h 36 min1,437 subs
Bortle 3Rural	6 min94 subs	25 min376 subs	1 h 40 min1,501 subs
Bortle 4Rural / suburban transition	7 min104 subs	28 min414 subs	1 h 50 min1,656 subs
Bortle 5Suburban	8 min119 subs	32 min476 subs	2 h 07 min1,901 subs
Bortle 6Bright suburban	10 min157 subs	42 min626 subs	2 h 47 min2,504 subs
Bortle 7Suburban / urban transition	15 min229 subs	1 h 01 min913 subs	4 h 03 min3,652 subs
Bortle 8City	23 min340 subs	1 h 31 min1,359 subs	6 h 02 min5,434 subs
Bortle 9Inner city	38 min578 subs	2 h 34 min2,309 subs	10 h9,235 subs

Adjust in the calculator

Power and kit for this session

Allowing for slewing, focusing and rejected subs, that is about 54 min of run time. The eQuinox 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.)

USB-C power bank 20000mAh 5V 2AUnistellar asks for a 5 V 2 A output; PD is not needed.
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How it frames

The Sombrero Galaxy is 9′ × 4′ across. The eQuinox 2 frames 0.76° × 0.57° at 1.33″ per pixel, so it fills 26% of the frame’s short side.

About the Sombrero Galaxy

The bright bulge and knife-edge dust lane are obvious within an hour. Low from northern Europe, so catch it near the meridian.

M104, NGC 4594 · Galaxy in Virgo · magnitude 8.0 · 9′ × 4′ · 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 Unistellar eQuinox 2

A 114 mm Newtonian with five times the light grasp of a 50 mm refractor. Fixed 4 s subs put it in read-noise territory under dark skies, but the aperture carries it. The published field is 45.6′ × 34.2′, a crop of the sensor.

Fixed 4 s subs in Enhanced Vision; they cannot be changed. No built-in filter. Unistellar sells only a solar filter and says a third-party filter is at your own risk and voids the warranty.

The eQuinox 2 uses fixed 4 s subs, so the only levers you have are the sky you shoot from, the filter, and total time.

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 Sombrero Galaxy with your eQuinox 2? Did the solid figure match?Anonymous, one tap. It is how the model gets calibrated.

Have an image of the Sombrero Galaxy from a eQuinox 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 Sombrero Galaxy · All targets for the eQuinox 2