M31 100" vs 12" LX600 Telescopes;
DSLR vs iPhone Imaging: M15 Globular Cluster
Posted: 7 December 2017
Cloudy skies returned on Monday, 27 November 2017, and continued for over a week. Sunday evening, 3 December, I was able to get two photos of December's perigee Full Moon (aka "SuperMoon") through the clouds using the iPhone 8 Plus 2X lens and the iOS app NightCap Camera:
Monday, 4 December, began mostly sunny with no precipitation in the forecast. I decided to take advantage of the good weather and apply another coat of varnish to one section the POD Zenith Table. For some reason this particular section had begun showing signs of weathering even though I had originally applied four coats of outdoor varnish in 2016:
Hopefully, the additional coat of varnish will help. I am still contemplating covering the wood with something like marine high density polyethelyne.
I have begun rereading the book "The Realm of the Nebulae" by Edwin Hubble, first published in 1936. I last read my copy as a teenager back in the early 1960s.
When I started the book the frontispiece caught my attention. It shows a portion of Messier 31, which was known as the "Great Spiral in Andromeda" in 1925 when the plate was taken using the 100 inch telescope at Mount Wilson Observatory. I realized I had taken almost the same image with my 12" LX600 in October 2016. Here are the images side-by-side at similar scales:
Click or tap on image for larger version
We've come a long ways since 1925!
Clouds returned later in the day on Monday. Before sunrise Wednesday morning, 6 December, there was some brief rain (0.04"). The sky began clearing after sunrise.
Open: Wednesday, 6 December 2017, 1817 MST
12" f/8 LX600 w/StarLock
2" 24mm UWA eyepiece
1.25" 15mm eyepiece
iPhone 8 Plus
1823 MST: LX600 ON, StarLock OFF, High Precision OFF.
SYNCed the AutoStar II on the star Altair.
Viewed M15 (globular cluster), 102X.
Mounted the D7200 DSLR at prime focus. Focused on Altair using a Bahtinov Mask. Locked the mirror. Slewed to M15.
1900 MST: StarLock ON.
M15, StarLock autoguided, 1 minute, ISO 1600, White Balance 3570K:
1907 MST: StarLock OFF. Removed DSLR.
Viewed M15, 163X.
Mounted the iPhone 8 Plus on the 15mm eyepiece.
1916 MST: StarLock ON.
M15, afocal 163X, StarLock autoguided, 1 minute, ISO 5000 (NightCap Camera Long Exposure, Light Boost, 1/3sec):
1918 MST: StarLock OFF.
This was not my best iPhone image of M15. I got that on 29 October 2017.
1920 MST: clouds began appearing in the southern sky.
1924 MST: did some mirror lock tests.
SYNCed the AutoStar II on the star Aldebaran.
1931 MST: besides the clouds coming in, breezes were picking up.
Closed the air conditioner vent. Will likely not need to use the AC this winter.
Viewed M1 (Crab Nebula), 102X.
Then began closing up for the night.
1949 MST: LX600 OFF.
Close: Wednesday, 6 December 2017, 2000 MST
Session Length: 1h 43m|
Conditions: Still most clear, breezy
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