Annotation

Every object in your picture,named in one click.

Akastroid plate solves the field, then labels the galaxies, nebulae, clusters and bright stars on it - the kind of annotated image you have seen made with PixInsight, without the scripts, the catalogue downloads or the settings.

Free to try. Nothing is uploaded, and there is no account to create.

The Hercules Cluster M13 annotated in Akastroid: the cluster ringed and named, with the galaxies NGC 6207 and IC 4617 and bright stars labelled

The Hercules Cluster, processed and annotated in Akastroid - the galaxies beside it named too. More in the gallery.

The faint smudge gets a name

Almost every deep-sky image holds more than its target. The galaxy you framed has companions; the nebula has a reflection nebula tucked beside it; there is a cluster in the corner you never noticed. Annotation is how you find out what you actually caught - and very often it is the favourite part of the whole process.

One click, from stack to labelled image

Press Identify objects. Akastroid matches the stars in your image against its catalogue, works out exactly where the telescope was looking and at what scale, and draws the names straight onto the preview. There is no separate apply step and nothing to set up first.

  • Deep sky - about twelve thousand galaxies, nebulae, clusters and planetary nebulae, with their common names.
  • Stars - bright stars labelled with their magnitude and colour.
  • Coordinate grid - optional, drawn faint so it is there when you look for it.

Shapes, not just circles

A circle is the wrong shape for a galaxy. Where the catalogue records an object's size and orientation - over ten thousand of them do - the marker is an ellipse turned to the object's real angle on your frame, because the plate solve knows how your camera was rotated. Andromeda is traced along its length; the Leo Triplet gets three ellipses that match three galaxies.

Readable in a crowded field

The Orion Nebula is the classic test: four catalogued objects in one patch of sky. Objects inside a larger one get a small marker that says "here" without drawing a second ring across the first; two big neighbours shrink until their rings touch; large rings carry their label inside so it cannot be read as naming the next one along; and a star label that would print over another is left out.

Written into the export

The labels are part of the image you export - JPEG and PNG for posting, TIFF for printing - so what you share is the annotated picture itself, not a screenshot of your screen. Remove them with one click when you want the clean version too.

What it needs, honestly

The solve starts from where your files say the telescope was pointing. FITS from a smart telescope, ASIAIR, N.I.N.A., Ekos or any tracking mount records that, and a stack that already carries a WCS is verified star by star rather than trusted. A tripod DSLR raw carries no coordinates, and Akastroid tells you so instead of guessing. A stacked image that came out mirrored is handled: the field is tried both ways round.

Part of the whole workflow

Annotation sits at the end of the same deep-sky workflowthat calibrates, stacks, removes gradients and calibrates colour against measured stars. If you are coming from PixInsight, the comparison page covers the rest of the difference.

Is this like PixInsight's ImageSolver and AnnotateImage?

It does the same job - solve the field, then draw the catalogue over it - in one click instead of two scripts and a settings dialog. There is no catalogue to download and nothing to configure: the catalogues ship inside the application.

What does it need from my files?

Roughly where the telescope was pointing. FITS from a Seestar, ASIAIR, N.I.N.A., Ekos or any tracking mount records it, and so does a stack that already carries a WCS. A DSLR raw from a tripod does not, and Akastroid says so rather than guessing: a blind all-sky solve is not attempted, because a confident wrong answer is worse than an honest refusal.

What gets labelled?

Galaxies, nebulae, clusters and planetary nebulae from a catalogue of about twelve thousand objects, with the familiar names people search for - the Running Man, De Mairan's Nebula, the Flame - and bright stars with their magnitude and colour. A coordinate grid can be added on top.

Why are some markers ellipses?

Because galaxies are not round. Where the catalogue records an object's shape, the marker follows it at its real angle on your image, so Andromeda gets a long tilted ellipse around the whole galaxy instead of a circle that is either far too big or only around the core.

Does it get cluttered in a busy field?

It is built not to. An object inside a larger one - De Mairan's Nebula inside the Orion Nebula - gets a small marker instead of a second big ring; two large neighbours shrink until their rings touch rather than cross; and a star whose label would print over another label is left out.

Can I post the labelled image?

Yes. The overlay is applied to the image and written into the JPEG, PNG or TIFF you export, and it can be removed again with one click if you want the clean version as well.

See what else is in your last image.

Free to try on your own data. Nothing is uploaded.