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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

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Uploaded on November 10, 2018
Taken on November 13, 2018