The Southern Cross Galaxy In Hydra (NGC3621)

A spiral galaxy in the constellation Hydra.

This galaxy is called the Frame Galaxy, but it is also known as the Southern Cross Galaxy.
My previous attempt to photograph it was disastrous because I couldn't visualize the frame shape. This time, however, I tried again knowing that it has the very clear name of the Southern Cross.
The four bright stars of our own galaxy are arranged in a cross shape surrounding this galaxy (rotated about 30 degrees clockwise). This photograph is oriented with north at the bottom to make the cross shape clearer.
A notable feature of this galaxy is the absence of a bulge and the unusually faint spiral arms.

うみへび座にある渦巻銀河

この銀河 Frame Galaxyと呼ばれているが、一方南十字星銀河とも呼ばれている。
以前撮影したときには額縁の形がイメージできず酷い結果になったが、今回は南十字星という極めて解りやすい名前があること知っての再挑戦であった。
この銀河を取り巻くように丁度私たちの銀河の4つの明るい星が十字に並んでいる(30度くらい右回りに回転してる)。十字の形がわかりやすいようにこの写真は北を下に向けている。
この銀河の特徴はバルジがない、渦巻きの腕が異常に淡いという感じだ。


Place: Astropical@CSky Observatory Saraburi Thailand (Bortle Class 3, Moon Phase 8.4%)
Shot Date:15th / Feb / 2026 20:27 (UTC+7)
TS TSRC10T Carbon Truss Prime Focus (250mm F/8 f/2000mm)
Filter: Antlia V-Pro Lumi, ,Optolong Ha 3nm,SVBony RGB Sets
L :60X180Secs Total 180minutes
R :20X180Secs Total 60minutes
G :20X180Secs Total 60minutes
B :20X180Secs Total 60minutes
Ha :12X300Secs Total 60minutes

Total 7hours

Palette: Target L-HaRGB
Star L-RGB
Gain: 200 , Offset 5
CCD: Player One Artemis-M Pro Bin2
Mount :iOptron CEM70G
De-Rotator : Wanderer Mini V2 (0 Deg)
Guide: SVBony 60mm F/4, QHY290C.
Controler: NINA
Pre-Processing APP Drizzle Droplet 0.9 Scale 1.0
Post-Processing PI,Affinity
Shot By Taro Seki Astropical.uk

Frame_Galaxy-RGB_1-crop-Edit01-Finish