Spiral Galaxy M101 in the Constellation of Ursa major [Explored #86]

Spiral galaxy M101 in the constellation of Ursa Major. The spiral arms are a little distorted due to encounters with some nearby dwarf galaxies - two were in my field of view.

 

Technical Card:

900/120mm f/7 Skywatcher Esprit 120 triplet refractor.

0.85 x Field corrector with 2 inch IDAS P3 LPS filter

ZWO ASI2600MC; 60 x 300 second subs, Gain 100, Offset 25, Temp = -15c.

 

EQ6 R pro mount . EQMOD control.

Pegasus Astro FocusCube 2 electronic focuser.

 

Session control; SharpCap 4.1 on laptop.

Controlled from inside house with iPAD

Automated plate solving GOTO and focusing. 8 secs at gain 635.

 

 

60 dark frames

50 flat frames (electroluminescent panel A, 3600ms exposure @ 0 gain).

 

Post processed in PixInsight 1.8.9.

 

Light Pollution and Weather:

Night 1: SQM (L) =20.3 m/as2

Clear throughout

 

Polar Alignment:

Error measured by PHD2= 4.1 arc minute.

RA drift +0.32 arcsec/min

Dec drift +0.63 arcsec/min

 

Guiding:

PHD2 guiding with ZWO ASI290mm/WO GuideStar 61.

Every 7th sub dithered.

RA RMS error 0.66arcsec

Dec RMS error 0.59arcsec

 

Astrometry

Resolution ............... 0.900 arcsec/px

Observation start time ... 2025-03-23 20:52:58 UTC

Observation end time ..... 2025-03-24 02:35:13 UTC

Focal distance ........... 861.81 mm

Pixel size ............... 3.76 um

Field of view ............ 1d 33' 42.7" x 1d 2' 38.1"

Image center ............. RA: 14 03 25.884 Dec: +54 19 13.67

Done