M 33
M 33 — spiral arms and stellar nurseries in an Askar mosaic
M 33, the Triangulum Galaxy, lies beyond the Milky Way and shares the Local Group with it and M 31. Its relatively open view makes its disk an instructive counterpart to highly inclined Andromeda. It lacks a prominent classical bulge; the bright centre blends into an extended, finely structured stellar disk.
Blue arms, dark dust and pink gas clouds. The photograph reveals bright stellar associations and irregular dust lanes among the arms. Reddish knots trace luminous H II regions. NGC 604 is particularly conspicuous; NGC 595, NGC 592 and NGC 588 are other catalogued star-forming regions. The image shows their light and structure, not a quantitative measurement of gas mass or star-formation rate.
A new image version with mixed origins. The current mosaic was recorded predominantly with the ASI585MC Air on an Askar 120APO at 840 mm focal length. One panel from the 800 mm GSO Newtonian remains on the left side. The photographer confirmed this telescope identification.
Six close-ups explore the inner disk, large emission regions and fainter outskirts. Object annotations use the astrometric solution of the current file. Read more in Galaxy types and Galaxy evolution.
Where in the sky
The rectangle is this image's real field of view, with its measured rotation — not a symbol. Constellation figures and star positions come from SIMBAD.
3 entries sit within 27° of each other here — click a field to jump to it.
Crops
Nucleus and inner disk
Nucleus and inner disk
19.5′ × 17.6′·01h 33m 51.89s +30° 39′ 14.8″
The bright central stellar concentration blends into the structured disk without a prominent classical bulge. Dark lanes divide the starlight, while reddish gas regions highlight individual areas. The stars and gas clouds belong to the same galactic system.
NGC 604 and NGC 595
NGC 604 and NGC 595
22.3′ × 23.8′·01h 33m 52.33s +30° 46′ 14.6″
NGC 604 and NGC 595 are the conspicuous emission regions in this field. Their warm colours contrast with the bluish light of surrounding stellar associations. The annotations distinguish catalogued nebulae from stars and other objects along the same line of sight.
Northern arm and outer emission regions
Northern arm and outer emission regions
27.1′ × 28.4′·01h 34m 03.47s +31° 00′ 08.0″
This crop follows the transition to fainter parts of the disk. Alongside IC 132 and IC 133, the catalogued complexes BCLMP 652 and BCLMP 657 lie in the field. Declining surface brightness does not mark a sharp physical edge to the galaxy.
BCLMP 250 and HD 9483
BCLMP 250 and HD 9483
16.0′ × 17.2′·01h 33m 35.33s +30° 21′ 02.7″
The annotations identify emission complexes BCLMP 250 and BCLMP 257 and foreground star HD 9483. The star belongs to the Milky Way; its apparent proximity to M 33’s gas clouds is a line-of-sight overlap.
NGC 588, NGC 592 and BCLMP 274
NGC 588, NGC 592 and BCLMP 274
22.7′ × 11.8′·01h 32m 38.53s +30° 29′ 56.8″
The wider view connects several emission regions in the outer disk. NGC 588, NGC 592 and BCLMP 274 are labelled in the overlay. The reddish knots and surrounding starlight reveal different aspects of the same galactic structure.
NGC 592 and NGC 588
NGC 592 and NGC 588
14.6′ × 11.1′·01h 33m 00.42s +30° 33′ 18.8″
Two catalogued star-forming regions in context: NGC 592 and NGC 588. Their brightness and shapes differ although both belong to M 33’s disk. The circles help locate them and do not measure their boundaries.
Acquisition and processing
Optics and camera. Predominantly an Askar 120APO at 840 mm with a ZWO ASI585MC Air. One 800 mm Newtonian panel remains on the left side of the mosaic.
Exposure accounting. Embedded source data record 249 light frames totalling 42,540 seconds from September 2026. A complete, independently reconciled exposure inventory for all mosaic panels is not available here, so no mosaic-wide integration total is claimed.
Current output. The publication-ready AVIF measures 5472 × 3327 pixels. Its own plate solve gives 0.7103″/pixel, a field of 1.080° × 0.656°, and 176 reference stars with 0.274″ RMS. The inherited 0.355″/pixel source value does not describe the grid of this resized final version. Close-ups and overlays use the current file’s solution. The HDR gain map and SDR rendering are retained.