Celestron

Celestron NexStar 127SLT

Name: Celestron NexStar 127SLT
Brand: Celestron

A 5-inch Maksutov on Celestron's lightweight SLT GoTo mount: the most planetary aperture you can get in a computerized Celestron at this price, as long as you accept a mount that is working near its limit.

78/ 100

Polaris Score

Performance · ease · portability · upgrade path

See the breakdown ↓

Aperture

127mm

Focal Length

1500mm

Focal Ratio

f/12

Mount Type

Motorized Alt-Azimuth GoTo

Optical Design

Maksutov-Cassegrain

Weight

8.5 kg

From$749.95

Price tracked by PolarisObserved 3 timesTracking since Mar 2026

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Where to buy

High Point ScientificBest price$749.95→Agena AstroProductsPartnerOut of stock$749.95→

Verified 13h ago · prices tracked daily

What it's built forOpen these in the simulator →

This telescope lives for the planets.

An f/12 focal length built to magnify. Where fast scopes sweep wide, this one holds a single planet rock-steady at high power — a telescope for the patient observer on a steady night.

Sweet spot 100–160×Loves steady seeing

The view people remember

Saturn, with its rings tilted wide.

The one you call people outside to see — the rings standing clear of the planet, the Cassini Division a clean black line drawn around them.

See Saturn through this telescope →

Where else it shines

Never gets old

The Moon

Crisp crater rims and fine surface texture, ridges visible inside maria

Open view →

Also excellent on

Jupiter

Recognizable disk with subtle markings under steady seeing

Open view →

Within reach

Orion Nebula

Stronger structure — embedded stars plus dark lanes within the core

Open view →

Easy first target

The Pleiades

Rich field — fainter members fill out the cluster

Open view →

✦

Wide-field nebulae belong to another kind of telescope. This one trades width for reach.

01What it's good at

What it's best at — and the trade-offs.

127 mm of Maksutov aperture at 1500 mm shows Jupiter's cloud belts, Saturn's Cassini Division and lunar craterlets at magnifications a short tube rarely…

Best at

✓127 mm of Maksutov aperture at 1500 mm shows Jupiter's cloud belts, Saturn's Cassini Division and lunar craterlets at magnifications a short tube rarely reaches.

✓The GoTo mount keeps targets centered at 150x and above, where an untracked view drifts out of the field in under a minute.

✓The sealed Maksutov tube holds collimation indefinitely, so there is no mirror alignment to learn before the first night.

✓The whole kit weighs about 8.5 kg and carries out in one trip, which makes short weeknight planetary sessions realistic.

Trade-offs

!The 8.7 lb tube is just over the mount's rated 8 lb load, so expect a second or two of shake after focusing at high power.

!The narrow f/12 field means large objects such as the Andromeda Galaxy and the Pleiades will not fit in the eyepiece.

!The mount runs on eight AA batteries that drain quickly in the cold, so a power supply is close to essential.

!The closed tube needs 30 to 45 minutes to cool before planets look their sharpest.

02In plain English

What These Numbers Mean

127mm · f/12 · 1500mm FL · Motorized Alt-Azimuth GoTo

Aperture

127 mm (5 inch)

Five inches gathers about 55 percent more light than the 102 mm Maksutov in the NexStar 4SE, which shows as finer planetary detail and tighter double-star splits. It brings the brighter globular clusters and the Ring Nebula into range, while faint galaxies stay dim.

Focal length

1500 mm

A 10 mm eyepiece gives 150x with no Barlow, so planetary magnification comes easily. The same long focal length frames Jupiter, Saturn and individual lunar craters naturally, but anything wider than about half a degree overflows the view.

Focal ratio

f/12

Slow optics are forgiving: inexpensive eyepieces stay sharp to the edge and focus is easy to find. The cost is a narrow, dim view of extended deep-sky objects, which is why this is a Moon, planets and doubles telescope first.

Optical design

Maksutov-Cassegrain

A thick meniscus corrector seals the tube and holds the optics permanently aligned, so there is no collimation and almost no maintenance. Its trade-off against a Newtonian of similar size is a much narrower field and a longer wait for the glass to cool.

Mount

SLT single-arm alt-azimuth GoTo

The mount finds and tracks over 40,000 objects, but it is rated for 8 lb and this tube weighs 8.7. Views settle after a moment, and a touch on the focuser at 150x makes the image wobble briefly. The tube's CG-5 dovetail lets it move to a sturdier mount later.

Cooldown

30–45 minutes

Until the corrector and mirror reach outdoor temperature, warm air inside the sealed tube softens planetary detail. Carry it out when you start dinner, not when you want to observe, and the planets will be noticeably sharper.

03The Polaris Score

How it scores, and why.

78/100

78/ 100

Celestron NexStar 127SLT

Performance

Ease of use

Portability

Upgrade potential

Polaris weighs optical capability, how easy the scope is to live with, how portable it is, and how far it takes you before you outgrow it — not list price or brand.

04Who it's for

An honest fit check.

Lunar and planetary observers who want GoTo and tracking in a compact package

Buy it if you

✓Lunar and planetary observers who want GoTo and tracking in a compact package

✓Beginners who would rather the telescope find things than learn star-hopping first

✓Apartment or balcony observers who need a short tube and a light, one-trip kit

Look elsewhere if you

!Deep-sky observers who want wide fields, since f/12 cannot frame large nebulae or the Pleiades

!Anyone who wants a rock-steady view at high power, since the light mount shakes after every touch

!Long-exposure astrophotographers, since the alt-azimuth mount cannot track without field rotation

05Build your rig

What to buy next — and where it leads.

7 pieces of gear, ordered by what changes the view most

Recommended upgrades

Observe all night, no AA batteries★ Top pickCelestron PowerTank Lithium

Runs the GoTo mount all night instead of draining eight AA batteries

$99.95View details →

A sharper everyday viewCelestron X-Cel LX 12mm

125x on this tube, the magnification you will use most on the planets

$109.95View details →

Tame lunar glareGSO Moon Filter 13pct 1.25-inch

Cuts the glare of a full Moon through five inches of aperture

$11.95View details →

Imaging path

Visual observing tonightMotorized Alt-Azimuth GoTo✓ Included

Ships with this telescope — point-and-track for visual sessions, no extra setup.

Better tracking & light imagingCelestron Advanced VX (AVX) Equatorial Mount✓ Compatible

$1,099View details →

Portable astrophotographyZWO AM5N Harmonic Equatorial Mount✓ Compatible

$2,299View details →

Start imagingZWO ASI662MC

$199View details →

Lunar & planetary

Excellent

Deep-sky visual

Narrow field

Astrophotography

Lunar and planetary only

06The numbers

Full specifications.

6 measured and stated values

Optics

Optical DesignMaksutov-Cassegrain

Aperture127mm

Focal Length1500mm

Focal Ratiof/12

Mount & drive

Mount TypeMotorized Alt-Azimuth GoTo

Physical

Weight8.5 kg

Editor’s Take

The 127SLT pairs a 127 mm Maksutov-Cassegrain ("Mak"), a sealed design that folds 1500 mm of focal length into a 15-inch tube, with the same single-arm GoTo mount Celestron uses on the 130SLT. After a short SkyAlign the mount finds and tracks the Moon, planets and double stars for you, and the Mak's long focal length gives sharp, high-contrast views of them with almost no maintenance. The catch is the pairing: the tube weighs slightly more than the mount's rated load, so the image shakes for a moment after every focus touch. It costs the same as the NexStar 4SE, which has a steadier mount and a smaller tube; the 127SLT is the choice when the extra inch of aperture matters more to you than the steadiness.