Messier 81 and 82
M81 is a large spiral galaxy in Ursa Major that is reasonably local to us at 12 million light years. Its companion, M82 has been disrupted by an encounter with M81 in the past.
M82 is a starburst galaxy with intense star formation triggered by the gravitational influence of M81. The red fan-like filaments at right angles to the axis of the galaxy are formed by a "superwind". The intense star formation has resulted in multiple supernovae explosions occurring about once every 10 years - the explosions power the super wind. The filaments are expanding outwards at about 600 miles a second and glow brightly in hydrogen alpha (red). They are also a very strong source of radio emission, listed as 3C 231 in the 3rd Cambridge catalogue of radio sources.
A very faint satellite galaxy to M81 - Holmberg IX can just be seen as a faint blue smudge above its parent galaxy.
Equipment-
900/120mm f/7.5 Equinox EDrefractor.
Star watcher x 0.85FR with 2 inch IDAS LPS D1 filter
ZWO ASI2600MC; 20 x 6 minute subs + (120 minute total integration).
NEQ6 Pro Mount with Rowan modified belt drives. Plate solving GOTO.
Laptop with SharpCap 4.0 for focusing and acquisition.
Calibration-
30 dark frames
30 flat frames (Electroluminescent panel @ 150ms)
QHY Polemaster alignment -
Error measured by PHD2= 0.6 arc minute.
RA drift +0.28 arcsec/min
Dec drift -0.14 arcsec/min
Guiding-
PHD2 guiding with ZWO ASI290mm/Altair lightwave 209/50mm secondary scope. Alternate subs dithered.
RA RMS error 0.40 arcsec, peak error -1.84 arcsec
Dec RMS error 0.39 arcsec, peak error -2.54arcsec
Astrometry-
Center (RA, hms):09h 55m 39.082s
Center (Dec, dms): +69° 20' 28.639"
Pixel scale: 0.97 arcsec/pixel
Light Pollution-
SQM (L) at middle of session (2350 hrs UT) 20.2 mag/arcsec2 .
Typical of outer suburbs - Bortle scale = 5/9 Yellow
Environmental-
Temp = -0.5c
Humidity = 99%
Dew point = -0.7c
Occasional light cloud.
Post processed in PixInsight 1.8.
Messier 81 and 82
M81 is a large spiral galaxy in Ursa Major that is reasonably local to us at 12 million light years. Its companion, M82 has been disrupted by an encounter with M81 in the past.
M82 is a starburst galaxy with intense star formation triggered by the gravitational influence of M81. The red fan-like filaments at right angles to the axis of the galaxy are formed by a "superwind". The intense star formation has resulted in multiple supernovae explosions occurring about once every 10 years - the explosions power the super wind. The filaments are expanding outwards at about 600 miles a second and glow brightly in hydrogen alpha (red). They are also a very strong source of radio emission, listed as 3C 231 in the 3rd Cambridge catalogue of radio sources.
A very faint satellite galaxy to M81 - Holmberg IX can just be seen as a faint blue smudge above its parent galaxy.
Equipment-
900/120mm f/7.5 Equinox EDrefractor.
Star watcher x 0.85FR with 2 inch IDAS LPS D1 filter
ZWO ASI2600MC; 20 x 6 minute subs + (120 minute total integration).
NEQ6 Pro Mount with Rowan modified belt drives. Plate solving GOTO.
Laptop with SharpCap 4.0 for focusing and acquisition.
Calibration-
30 dark frames
30 flat frames (Electroluminescent panel @ 150ms)
QHY Polemaster alignment -
Error measured by PHD2= 0.6 arc minute.
RA drift +0.28 arcsec/min
Dec drift -0.14 arcsec/min
Guiding-
PHD2 guiding with ZWO ASI290mm/Altair lightwave 209/50mm secondary scope. Alternate subs dithered.
RA RMS error 0.40 arcsec, peak error -1.84 arcsec
Dec RMS error 0.39 arcsec, peak error -2.54arcsec
Astrometry-
Center (RA, hms):09h 55m 39.082s
Center (Dec, dms): +69° 20' 28.639"
Pixel scale: 0.97 arcsec/pixel
Light Pollution-
SQM (L) at middle of session (2350 hrs UT) 20.2 mag/arcsec2 .
Typical of outer suburbs - Bortle scale = 5/9 Yellow
Environmental-
Temp = -0.5c
Humidity = 99%
Dew point = -0.7c
Occasional light cloud.
Post processed in PixInsight 1.8.