07/31/21
Location: Anza desert site,
Bortle 3.5
Equipment: Celestron 9.25” Edge HD
SCT and Celestron 150ST
achro on
SW SkyTee 2 manual AltAz mount.
Upon arrival to Anza desert I have discovered that the dirt track to the dark site was eroded with water from recent thunderstorms. Some gullies were a couple feet deep. Nothing my 4Runner can’t handle, but no racing today.
Can’t imagine that much rain in the desert in the middle of summer, but I guess when they issue flashflood warning they are not kidding.
Another surprise was that chaparral started to bloom. One of my favorite times in the desert! I missed it last year, will enjoy this summer. I will snap some pics when there will be more flowers.
20:58. The session started with a bang – bright white meteor with smoke trail, going westwards from Cingus.
My original plan was to observe
DSOs until half Moon rises ~00:30 and then do some lunar and planetary. However, when I checked SkySafari I discovered that something special was to happen early morning on Jupiter. So, the new plan was to have a shorter
DSO version, sleep for three hours and then observe Jupiter.
Most of this season I was hunting galaxies. Now it was time to catch some star clusters, and Sagittarius/Scorpio is the premium area for that. I just pointed the scopes at the Scorpio tail and spent entire evening within the same 5 degrees
FOV of
RACI.
Scorpio
Ptolemy’s (M7) and Butterfly (M6) Clusters dominate the area. Due to their larger size and brightness they were presented better in 150ST refractor compared to Edge 9.25”
SCT. This was the general rule for the evening: open clusters stood out better from the field in 150ST, however 9.25” Edge has shown more stars in clusters.
Antalova 1 (Ant 1) –
OC – better presented in 150ST/ TV Panoptic 27mm (28x). Two bright stars dominate the cluster with two chains of fainter stars forming seagull shape below in the field of faint stars. Not detached from field.
Antalova 2 (Ant 2) –
OC – below Ant 1, small chain of 5 stars with background glow. Better presented in 150ST/ Pentax XW10 (75x).
Antalova 3 (Ant 3) –
OC – forms triangle with Ant 1 and Ant 2. W-shaped patch of ~20 stars with two bright stars above. Edge 9.25”/Pentax XW20 (118x) and 150ST/ Pentax XW10 (75x) delivered similar views.
Antalova 4 (Ant 4) –
OC – next to
NGC 6383. ~10 stars form small parallelogram patch well detached from field. Edge 9.25”/Pentax XW20 (118x).
NGC 6383 –
OC – large cluster in the same
FOV with M6, contains several chains of faint stars, dominated by bright HJ 4962 multiple star. 150ST/ TV Panoptic 27mm (28x).
HJ 4962 – multiple star – 5.7, 10.5, 10.9, ab5.9”, ac14”. Neat double due to differences in brightness and proximity of faint silvery companions to the bright, warm white main. Edge 9.25”/Pentax XW20 (118x).
Tr 28 (Cr 337) –
OC – tiny star patch in 150ST/ TV Panoptic 27mm (28x), detached from field. 20+ stars resolved with Edge 9.25”/Pentax XW20 (118x).
NGC 6404 –
OC – very faint patch of many dim stars, resolved with averted vision in Edge 9.25”/Pentax XW20 (118x).
Tr 27 (Cr 336) –
OC – small triangle detached from field in 150ST/ TV Panoptic 27mm (28x). Diamond patch formed by 7 multi-colored stars with two star chains forming V-shape below in Edge 9.25”/Pentax XW20 (118x). Nice looking cluster.
Tr 29 (Cr 343) –
OC – 3 bright and a few faint stars forming triangular patch. Edge 9.25”/Pentax XW20 (118x).
It was close to midnight – time to catch some sleep before the second half of the session.
Triple Jupiter transit
I woke up ~02:30 to get a head start. Aimed scopes at Jupiter and immediately saw in both scopes small, sharp, deep black circle of Ganymede shadow closer to the left rim and dark brown circle of Ganymede itself on the right portion of Jupiter disk.
GRS was not immediately visible. I have played with EPs and selected Pentax XF 8.5mm (276x) for the Edge 9.25”, and Pentax XW3.5 (214x) for 150ST. For this session I have stopped 150ST to 90mm to improve its planetary performance. Still, on this night of better seeing Edge 9.25” had obvious advantage in terms of sharpness, contrast and resolution over 150ST.
30 min later
GRS moved closer to the center and was resolved in both scopes. Ganymede disk was sitting in the middle of the South Equatorial Belt, touching the top edge of
GRS. I don’t know if you noticed, but for the last couple of seasons
GRS color seemed to pale down. It used to be easy to spot by reddish-salmon color as oppose to brownish belts. Now
GRS color seems close to the belts color.
While Ganymede, its shadow and
GRS were easy to spot in 150ST, the fine details on Jupiter disk were not resolved. In contrast, Edge 9.25” has shown intricate structure of South and North Equatorial Belts and resolved Red Spot Hollow surrounding
GRS, and the lighter
GRS “eye”. I have not seen such amount of the details in years. Unfortunately, due to proximity to Jupiter opposition, North and South Polar Regions were lost in glare. I did stack Baader Moon and Sky Glow and Contrast Booster filters to fight it, but it was not enough. I will try to add a neutral filter next time.
At 03:15 Europa shadow finally moved on the Jupiter’s right edge. It was smaller, less sharp and of dark gray color, while Ganymede shadow was sharp black. For three brief minutes both shadows were visible as seen in the sketch below, and then Ganymede’s shadow slid off.
That was exciting! After a few minutes of contemplation I hit the sleeping bag to get some sleep before sunrise.