Wrapping up galaxy season
Posted: Wed May 11, 2022 10:22 pm
Time of the year to finish with galaxies ....
Just thought that I'd post up a few of my better 'end of season' galaxy images. All using the F 4.0 VX12 and ZWO ASI 294 cameras - sometimes supplemented with a few good frames from the PDS200 taken last year (obvious where stars exhibit 8 rather than 4 diffraction spikes). Techniques exactly the same as previously posted for M51, M94 and M101 so no point labouring that again i.e. so generally
1) about 3-3.5 h of OSC frames
2) sometimes sharpened at the core by mixing in the luminance from ~ 40-50 min of short (3-5s) exposure mono frames to construct a high dynamic range luminance channel - sometimes also combining this process with some sharpening via deconvolution
3) sometimes adding HA into the red channel to higlight the HA features of galaxies
4) mainly all at Bortle 6
M63 - the sunflower galaxy. I really like this object. One of the few astro objects truly worthy of it's name. This galaxy exhibits lots of bright fine structure near the centre and here adding the deconvoluted mono luminance was worthwhile and added real detail. Adding in HA also nicely localized star forming regions within the galaxy.
M81 - the HA detail is attractive but there is no fine structure at the core (that I could detect anyway) to justify trying to improve sharpness. So this picture is purely OSC frames plus HA at Bortle6.
M109 family - This barred spiral galaxy is rather distant (55 Mly or more) and part of the attraction is also to visualise its orbiting family of smaller galaxies. So no supplementation with HA (not detected very efficiently anyway because of red-shift to the edge of the filter pass band) but included more than an hour of frames under Bortle4 skies since the main imperative for this image was simply to gather more photons.
M106 - the extra HA arms are a really key and interesting feature of this galaxy. So the HA was imaged for longer (2.5h). There is also some fine detail near the core and so mono luminance and deconvolution were alos used for this image. The added detail is rather subtle but the image is clearly improved.
Hope next year to add M64 and a few others under dark skies if possible ...
Tim
Just thought that I'd post up a few of my better 'end of season' galaxy images. All using the F 4.0 VX12 and ZWO ASI 294 cameras - sometimes supplemented with a few good frames from the PDS200 taken last year (obvious where stars exhibit 8 rather than 4 diffraction spikes). Techniques exactly the same as previously posted for M51, M94 and M101 so no point labouring that again i.e. so generally
1) about 3-3.5 h of OSC frames
2) sometimes sharpened at the core by mixing in the luminance from ~ 40-50 min of short (3-5s) exposure mono frames to construct a high dynamic range luminance channel - sometimes also combining this process with some sharpening via deconvolution
3) sometimes adding HA into the red channel to higlight the HA features of galaxies
4) mainly all at Bortle 6
M63 - the sunflower galaxy. I really like this object. One of the few astro objects truly worthy of it's name. This galaxy exhibits lots of bright fine structure near the centre and here adding the deconvoluted mono luminance was worthwhile and added real detail. Adding in HA also nicely localized star forming regions within the galaxy.
M81 - the HA detail is attractive but there is no fine structure at the core (that I could detect anyway) to justify trying to improve sharpness. So this picture is purely OSC frames plus HA at Bortle6.
M109 family - This barred spiral galaxy is rather distant (55 Mly or more) and part of the attraction is also to visualise its orbiting family of smaller galaxies. So no supplementation with HA (not detected very efficiently anyway because of red-shift to the edge of the filter pass band) but included more than an hour of frames under Bortle4 skies since the main imperative for this image was simply to gather more photons.
M106 - the extra HA arms are a really key and interesting feature of this galaxy. So the HA was imaged for longer (2.5h). There is also some fine detail near the core and so mono luminance and deconvolution were alos used for this image. The added detail is rather subtle but the image is clearly improved.
Hope next year to add M64 and a few others under dark skies if possible ...
Tim