| Object : | M92, Globular Cluster. |
| Coordinates/Direction : | RA: 17h17m, DEC: +43o08' |
| Object size : | 14' |
| Object magnitude : | 6.3 |
| More to know : |
Wikipedia:
https://en.wikipedia.org/ wiki/ Messier 92 |
| Date : | 2023-03-09 |
| Time (UT) : | 00:15 to 01:04 |
| Mount : | Skywatcher EQ6 Pro controlled by EQMOD and
KStars Ekos/Indi |
| Guide : | Ekos internal guider in dithering mode, QHY5 camera with 200 mm f/3.5 lens |
| Lens/telescope : | Pentax 645 300 mm ED f/4, external focus motor,
Pentax 645 project page |
| Corrector/Barlow : | - |
| Field (FOV) : | 6.8x4.5 degree |
| Filter : | none |
| camera : | Canon 6D, temperature +2 C. Controlled by
KStars Ekos/Indi |
| Film/CCD : | Raw |
| Exp. time : | 60x60 seconds, iso1600 |
| Image process tool : | Siril, Gimp, Irfanview |
| Processing : | dark and flat calibrated |
| Weather : | clear sky and a temperature of -6 C |
| Site : | Sweden, Stockholm, Hagsätra. Bortle class 9 |
| Comment : |
This is one photography I took to show all of you that don't have a telescope.
A normal telephoto lens of high quality can do a lot even at small objects.
This global cluster has half the angle size of the Moon's diameter.
Click on the image and zoom in to see all the details.
It was discovered already 1777 by Johann Elert Bode.
The distance to it is 27'000 light years.
Its light is then 27'000 years old when it hit us.
The cluster's mass is equal to 330'000 Suns. |
| Date : | 2023-03-09 |
| Time (UT) : | 00:15 to 01:04 |
| Comment : |
It's small of course compare to the telescope photo below, but it's there. |
| Date : | 2020-03-13 |
| Time (UT) : | 21:49 to 00:27 |
| Mount : | EQ6 controlled by EQMOD |
| Guide : | PHD2 in dithering mode, QHY5 camera, 400 mm f/6.3 guide telescope |
| Lens/telescope : | TS130, 910mm f/7 |
| Corrector/Barlow : | Flat field corrector 3" x1 |
| Filter : | none |
| camera : | Canon 6D, controlled by APT software |
| Film/CCD : | Raw |
| Exp. time : | 106x60 seconds, iso1600, because of clouds I had to reject about ten images |
| Image process tool : | AstroImageJ, Fitswork, Irfanview |
| Processing : | Bias and dark handled with dithering, Synthetic flat calibrate, level. |
| Weather : | clear |
| Site : | Sweden, Stockholm, Hagsätra. Bortle class 9 |
| Comment : |
One more image of the globular cluster M92.
I want to see how my equipment perform after I hade rebuilt the mount, make a new routine for flat calibration and cleaned the sensors once again.
Now I see that the image is almost free from dust and stains, only one big blob left.
Normally I have to run filter to get rid of them, I didn't do that this time.
Good because a filter have some disadvantages on the object.
I let the background be much darker this time, but not totally black. |
| Date : | 2020-03-13 |
| Comment : |
And in this close up I see that the core of the globular cluster is not oversaturated. |
| Date : | 2019-02-29 |
| Time (UT) : | 21:55 to 23:43 |
| Mount : | EQ6 controlled by EQMOD |
| Guide : | PHD2 in dithering mode, QHY5 camera, 400 mm f/6.3 guide telescope |
| Lens/telescope : | TS130, 910mm f/7 |
| Corrector/Barlow : | Flat field corrector 3" x1 |
| Filter : | none |
| camera : | Canon 6D, controlled by APT |
| Film/CCD : | Raw |
| Exp. time : | 70x60 seconds, iso1600 |
| Image process tool : | AstroImageJ, Fitswork, Irfanview |
| Processing : | Flat calibrate, level, crop 1:1 800x800 center. |
| Weather : | clear |
| Site : | Sweden, Stockholm, Hagsätra. Bortle class 9 |
| Comment : |
A second chance to catch the globular cluster M92.
Good target to test the equipment at.
Still the focusing that I need more control over.
I try to optimize the temperature compensation of focus, not easy and a slow process. |
| Date : | 2019-02-04 |
| Time (UT) : | 00:32 to 01:49 |
| Mount : | EQ6 controlled by EQMOD |
| Guide : | PHD2 in dithering mode, QHY5 camera, 400 mm f/6.3 guide telescope |
| Lens/telescope : | TS130, 910mm f/7 |
| Corrector/Barlow : | Flat field corrector 3" x1 |
| Filter : | none |
| camera : | Canon 6D, controlled by APT |
| Film/CCD : | Raw |
| Exp. time : | 82x30 seconds, iso1600 |
| Image process tool : | AstroImageJ, Fitswork, Irfanview |
| Processing : | Flat calibrate, medium stack, level, crop 1:1 800x800 center. 0.6 Mpix of 5Mpix. |
| Weather : | clear |
| Site : | Sweden, Stockholm, Hagsätra. Bortle class 9 |
| Comment : |
It was three years since last time I took a photo of the globular cluster M92.
Now I have a new setup with longer focal length and less vignetting.
This time I only show the small center of the image. It is cropped with 1:2 pixel.
Is it possible to see any better resolution compare to earlier photo?
I haven't done anything to take away dust blobs this time. I have increased the ISO to 1600 and shorter exposure time.
The focal length is increased from 684 mm to 910 mm, gives better resolution but longer exposure times. |
| Date : | 2016-02-23, 02-25, 03-11 |
| Time (UT) : | - |
| Mount : | EQ6 controlled by EQMOD |
| Guide : | PHD2 in dithering mode, QHY5 camera, off-axis |
| Lens/telescope : | TS130, 910mm f/7 (682mm, f5.3) |
| Corrector/Barlow : | Riccardi flat field corrector 2.5" x0.75 |
| Filter : | none |
| camera : | Canon 6D, controlled by APT |
| Film/CCD : | Raw |
| Exp. time : | 105x60 + 57x120 seconds, iso800 |
| Image process tool : | DSS, Fitswork, Irfanview |
| Processing : | resize, level, cal dark&bias |
| Weather : | clear |
| Site : | Sweden, Stockholm, Hagsätra. Bortle class 9 |
| Comment : |
M92, a complement with 120 seconds exposures and stacked together with the older 60 seconds exposures.
The auto guiding was a little bit unstable this time. Stars FWHM about 4". |
| Date : | 2015-03-22 |
| Time (UT) : | 23:00 to 00:14 |
| Mount : | EQ6 controlled by EQMOD |
| Lens/telescope : | TS130, 910mm f/7 (682mm, f/5.3) |
| Corrector/Barlow : | Riccardi flat field corrector 2.5" x0.75 |
| Filter : | none |
| camera : | Canon 5D, controlled by APT |
| Film/CCD : | Raw |
| Exp. time : | 60x60 seconds, iso800 |
| Image process tool : | Fitswork, Irfanview |
| Processing : | resize, level, cal dark & bias |
| Weather : | clear |
| Site : | Sweden, Stockholm, Hagsätra. Bortle class 9 |
| Comment : |
M92 together with M3 and M13 are relative easy objects to catch on photo, no need of very long exposure time. |
English
(click on the image to get a full resolution photo in a new window)
