M20 – Trifid Nebula (2017/07/21)

Date:                   05/27/2017, 07/21/2017, 07/23/2017
Location:           Creston , Panoche Hills BLM, CA
Condition:         Excellent transparency, good to excellent seeing

Exposure:           R – 12x900s, G – 12x900s, B – 12x900s
Telescope:          Astronomics AT111EDT
Mount:                AP1100
CCD:                    SBIG STF8300M + Baader LRGBHaO3S2 filter

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IC405 – Flaming Star Nebula (2017/09/21)

Date:                   09/21/2017~09/23/2017
Location:            Calstar 2017
Condition:          Excellent seeing, light dew

Exposure:          R – 11x900s, G – 14x900s, B – 11x900s
Telescope:          Astronomics AT111EDT
Mount:                AP1100
CCD:                    SBIG STF8300M + Baader LRGBHaO3S2 filter

NGC7293 – Helix (2017/09/20)

Date:                   09/20/2017~09/23/2017
Location:            Calstar 2017
Condition:          Good to excellent seeing, light dew most nights

Exposure:           Ha – 23x1200s , O3 – 21x1200s, S2 – 10x1200s
Telescope:          Astronomics AT111EDT
Mount:                AP1100
CCD:                    SBIG STF8300M + Baader LRGBHaO3S2 filter

M23 (2015/06/23)

Date:                   06/13/2015, 06/14/2015
Location:            Lake San Antonio, CA
Condition:          Average to excellent seeing, light dew

Exposure:           L/R/G/B: 3x300s each filter
Telescope:          Astronomics AT111EDT
Mount:                CGEM
CCD:                    SBIG STF8300M + Baader LRGBHaO3S2 filter

NGC1499 – California Nebula (2017/10/25)

What’s California doing in space? Drifting through the Orion Arm of the spiral Milky Way Galaxy, this cosmic cloud by chance echoes the outline of California on the west coast of the United States. Our own Sun also lies within the Milky Way’s Orion Arm, only about 1,500 light-years from the California Nebula. Also known as NGC 1499, the classic emission nebula is around 100 light-years long. On the featured image, the most prominent glow of the California Nebula is the red light characteristic of hydrogen atoms recombining with long lost electrons, stripped away (ionized) by energetic starlight. The star most likely providing the energetic starlight that ionizes much of the nebular gas is the bright, hot, bluish Xi Persei just to the right of the nebula. A regular target for astrophotographers, the California Nebula can be spotted with a wide-field telescope under a dark sky toward the constellation of Perseus, not far from the Pleiades. (From APOD)

A test shot from my backyard at Sunnyvale, CA to test ATR8 reducer on AT111EDT.

Overall star shapes look fine across entire field, though at corners the stars are not round, and some even have weird shapes, which might have something to do with focus and tilt of focuser and 2″ EP connector.

Another note is that bright stars in L frame are much larger (and have bigger halos around them), so LRGB combination not only brings out many faint stars, it also makes bright stars much bigger, which swamps the center area of both clusters. To mitigate the issue, I generate a star mask of only small stars in L frame and apply it to RGB frame, the halo issue of bright stars get resolved and it does not affect faint stars either.

Date:                   10/25/2017, 10/27/2017, 10/28/2017
Location:            Sunnyvale, CA
Condition:          Excellent transparency, Excellent seeing, light dew

Exposure:           Ha – 29x900s
Telescope:          Astronomics AT111EDT + ATR8 reducer
Mount:                AP1100
CCD:                    SBIG STF8300M + Baader LRGBHaO3S2 filter

Double Cluster (2017/10/25)

A test shot from my backyard at Sunnyvale, CA to test ATR8 reducer on AT111EDT.

Overall star shapes look fine across entire field, though at corners the stars are not round, and some even have weird shapes, which might have something to do with focus and tilt of focuser and 2″ EP connector.

Another note is that bright stars in L frame are much larger (and have bigger halos around them), so LRGB combination not only brings out many faint stars, it also makes bright stars much bigger, which swamps the center area of both clusters. To mitigate the issue, I generate a star mask of only small stars in L frame and apply it to RGB frame, the halo issue of bright stars get resolved and it does not affect faint stars either.

Date:                   10/25/2017
Location:            Sunnyvale, CA
Condition:          Average transparency, Average seeing, light dew

Exposure:           L/R/G/B: 5x300s each filter
Telescope:          Astronomics AT111EDT + ATR8 reducer
Mount:                AP1100
CCD:                    SBIG STF8300M + Baader LRGBHaO3S2 filter

IC5070 – Pelican Nebula (2017/07/28)

The recognizable profile of the Pelican Nebula soars nearly 2,000 light-years away in the high flying constellation Cygnus, the Swan. Also known as IC 5070, this interstellar cloud of gas and dust is appropriately found just off the “east coast” of the North America Nebula (NGC 7000), another surprisingly familiar looking emission nebula in Cygnus. Both Pelican and North America nebulae are part of the same large and complex star forming region, almost as nearby as the better-known Orion Nebula. From our vantage point, dark dust clouds (upper left) help define the Pelican’s eye and long bill, while a bright front of ionized gas suggests the curved shape of the head and neck. This striking synthesized color view utilizes narrowband image data recording the emission of hydrogen and oxygen atoms in the cosmic cloud. The scene spans some 30 light-years at the estimated distance of the Pelican Nebula. (From APOD)

Date:                   07/23/2015, 06/21/2017, 07/28/2017
Location:            Henry Coe State Park, Morgan Hill, CA
Condition:          Excellent transparency, excellent seeing, breezy occationally

Exposure:           Ha – 15x1200s, O3 – 16x1200s, S2 – 19x1200s
Telescope:          Astronomics AT111EDT
Mount:                CGEM, AP1100
CCD:                    SBIG STF8300M + Baader LRGBHaO3S2 filter