Messier 45 - The Pleiades open cluster and reflection nebula
Taken on Wednesday nights session - Ive found the Canon 80D at least a stop or an ISO more sensitive than my old Canon 60Da so I cut my ISO level down to ISO400 - even with that the stars are much more bloated than I would like - I will probably go for 3 mins at ISO400 in future rather than 5 minutes used here.
Had to use a lot of complex morphological transform techniques in PixInsight to reduce star size.
Large B class stars that are gravitationally bound, transit through a dust cloud. Dust clouds tend to refract blue light and absorb red and infra-red (heat) light hence the predominantly blue appearance of the nebulae. The complex lines in the nebulae are thought to be due to magnetic field lines from the stars.
The diffuse blue nebulae are catalogued in the van den Berg catalog of reflection nebulae.
vdB 20 - the Electra nebula
vdB 21 - the Maia nebula
vdB 22 - the Merope nebula
vdB 23 - centred on Alcyone
480/80mm f/6 Altair Starwave refractor
Astro-modified Canon 80D at ISO400, IDAS LPS D1 filter, 21 x 5 minute subs.
NEQ6 pro mount with Rowan belt drives.
Mini-PC with WiFi
Mount WiFi control with ASCOM/AstroPhotography Tool
Camera WiFi control with Backyard EOS
30 dark frames
40 flat frames (electroluminescent panel @ 1/40s)
31 bias frames
Post processed in PixInsight 1.8 and Photoshop
Local parameters:
Temp: 3.7 - 3.9c
Humidity: 74- 79%
Pressure: 998.5 kPa
Camera Sensor Temp: 12-17c
Light Pollution and Weather:
SQM (L) at start of session (2305 hrs UT) =20.14 mag/arcsec2.
SQM (L) at end of session (0130 hrs UT) = 20.2 mag/arcsec2.
Clear, moderately windy at end.
Polar Alignment:
QHY Polemaster alignment -
Error measured by PHD2=0.1 arc minute.
RA drift + 1.93 arcsec/min
Dec drift -0.02 arcsec/min
Guiding:
PHD2 guiding with ZWO ASI290mm/Altair Starwave 206/50mm guider. Dithered.
RA RMS error 0.76 arcsec, peak error -2.73 arcsec
Dec RMS error 0.63 arcsec, peak error 2.94 arcsec
Astrometry:
Center (RA): 03h 46m 19.894s
Center (Dec): +23° 58' 37.974"
Size: 70.4 x 55.9 arcmin
Pixel scale: 1.59 arcsec/pixel
Messier 45 - The Pleiades open cluster and reflection nebula
Taken on Wednesday nights session - Ive found the Canon 80D at least a stop or an ISO more sensitive than my old Canon 60Da so I cut my ISO level down to ISO400 - even with that the stars are much more bloated than I would like - I will probably go for 3 mins at ISO400 in future rather than 5 minutes used here.
Had to use a lot of complex morphological transform techniques in PixInsight to reduce star size.
Large B class stars that are gravitationally bound, transit through a dust cloud. Dust clouds tend to refract blue light and absorb red and infra-red (heat) light hence the predominantly blue appearance of the nebulae. The complex lines in the nebulae are thought to be due to magnetic field lines from the stars.
The diffuse blue nebulae are catalogued in the van den Berg catalog of reflection nebulae.
vdB 20 - the Electra nebula
vdB 21 - the Maia nebula
vdB 22 - the Merope nebula
vdB 23 - centred on Alcyone
480/80mm f/6 Altair Starwave refractor
Astro-modified Canon 80D at ISO400, IDAS LPS D1 filter, 21 x 5 minute subs.
NEQ6 pro mount with Rowan belt drives.
Mini-PC with WiFi
Mount WiFi control with ASCOM/AstroPhotography Tool
Camera WiFi control with Backyard EOS
30 dark frames
40 flat frames (electroluminescent panel @ 1/40s)
31 bias frames
Post processed in PixInsight 1.8 and Photoshop
Local parameters:
Temp: 3.7 - 3.9c
Humidity: 74- 79%
Pressure: 998.5 kPa
Camera Sensor Temp: 12-17c
Light Pollution and Weather:
SQM (L) at start of session (2305 hrs UT) =20.14 mag/arcsec2.
SQM (L) at end of session (0130 hrs UT) = 20.2 mag/arcsec2.
Clear, moderately windy at end.
Polar Alignment:
QHY Polemaster alignment -
Error measured by PHD2=0.1 arc minute.
RA drift + 1.93 arcsec/min
Dec drift -0.02 arcsec/min
Guiding:
PHD2 guiding with ZWO ASI290mm/Altair Starwave 206/50mm guider. Dithered.
RA RMS error 0.76 arcsec, peak error -2.73 arcsec
Dec RMS error 0.63 arcsec, peak error 2.94 arcsec
Astrometry:
Center (RA): 03h 46m 19.894s
Center (Dec): +23° 58' 37.974"
Size: 70.4 x 55.9 arcmin
Pixel scale: 1.59 arcsec/pixel