Wednesday, January 20, 2021

received one experimental image request (Halifax)

The BGO worked one of the submitted Rosette experiment requests.

Offset from HIP 31130 in RA only by 50%. The mount moved left, or east, as expected.

The centre of the Rosette is to the right or west...

All, 60 second subexposures, 10 stacked shots, full frame. FITS Liberator, GIMP. North is up; left is east.

Rosette Nebula in luminance

Luminance.

Rosette Nebula in hydrogen alpha

Hydrogen. Wow.

Rosette Nebula in ionised oxygen

Oxygen. Hints...

Hey. They look good in terms of flats. Yeh.

That said, there appears to be some elongated stars. In all the images... Weird.

§

Looked closely at this for other things, double stars, mainly.

Up or north from centre is an above width unequal pair of stars. The bright member is actually a double. It's BD +06 02393 or J 349. Split by 5.2 seconds of arc, oriented west to east. Now that separation ordinarily near the optical limit of this system but the poor focus and stacking has elongated the stars horizontal. So, it's not splittable here. All the channels are poor in the same why so not is revealed in either the L, H, or O.

Further north is a fascinating little arc of stars winding counter-clockwise and getting dimmer as they go. This is HD 259480 or SLE 297. SkyTools 3 Pro reports that the first two stars are officially noted in the Washington Double Star database, at 21.6 arc-seconds. B, to the east is about 1 or 2 magnitudes fainter. The next star should be included! It's about twice the distance from A, dimmer still. The fourth star is actually a titch brighter than the third, to the south of the third. Very interesting... (And previously viewed.)

At the far right is the centre of the Rosette with the open cluster NGC 2244 and the big multi-star system, HD 46150 or GAN 3. (Also previously viewed.)

To the south-west from centre is an interesting grouping. HD 259332 aka BAL 2669. The A star is to the south. B looks very slightly dimmer in the image and slightly to the east. ST3P shows the B star is 3 magnitudes fainter but I don't think that's the case. The Object Info box says mag 9.5 and 9.6. That's better. C, dimmer still, is 3 to 4 times the AB separation to the north-east.

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