Sunday, September 9, 2007

Observing at Plettstone Sept 2007

My daughter Mimi and I arrived late Friday afternoon at Michelle Stone's beautiful home outside the historic Gold Rush town of Bear Valley, just north of Mariposa on California's Highway 49 in the Sierra Nevada Mountain range's western foothills, to enjoy a few days together exploring views of Yosemite Valley, the local history and a surprisingly good dark and transparent sky. Everything worked out wonderfully, and I will begin this report by thanking Michelle for her many years of friendship and her (and Paul Plett's) graciousness as our host. I arrived home at noon today, Sunday, tired and very satisfied.

I'll provide something of a historical travelogue to start, but if you're interested instead only in the night time observations, skip down a few paragraphs to the ****

For those who have never been to the area, Bear Valley was a center of placer mining from 1849 into the 1850's, and most notably the headquarters of the famous/infamous General John C. Fremont. Just to the north of Bear Valley, with a commanding view of the deep valley to the north out to Coulterville, Fremont built a fort to protect his mine holdings from claims jumpers. You can see the view here:

The famous/infamous California "bandito" Joaquin Murieta was known to practice his trade in the area around Bear Valley (as well as near Dinosaur Point, another TAC observing site at Pacheco Pass on highway 152). But John Fremont, he ended up selling his holdings in and around Bear Valley for $6 million, a nice tidy sum for its day.

During our stay, we spent an afternoon as well in Yosemite Valley, having driven the "long way", past where Fremont's fort was, though Coulterville (a quaint Gold Rush town), up to highway 120, and in an entrance I'd never been through. It had been eight years since I'd been there, and it just keeps growing more spectacular. The drive back via highway 140 along the Merced River was equally enjoyable. It was a wonderful day trip.

I'll finish the travel section mentioning again the drive back. Instead of going back through Mariposa, which is how we arrived, I took Mimi through Hornitos, to Cathy's Valley, Merced, etc. on the ride home. But back to Hornitos. We took a slow drive through. The sleepy town was another hotbed in the gold rush. Old brick facades still line the road (we were the only car on it).... one of them had a historic landmark plaque stating the building was the original store of one Domenico Ghirardelli, who on that spot began what is now a world famous chocolate company based in our own bay area. And to add more astronomy flavor to the chocolate story, one of Domenico's closest social contacts was a wealthy bay area resident named James Lick. Brings it close to home, and ties the personalities of the time together, doesn't it?


Of my astronomical observations, I'll say the conditions were quite good; both nights were comfortable, nearly t-shirt weather, with surprisingly good skies, steadiness was very acceptable most of the time with moments that were sub-par, but with a bit of waiting, things always improved. Transparency was very good, especially considering the fires in the state at the time. I was amazed to log a highly probably view of the difficult planetary nebula Abell 80, and picking off all seven member of Hickson 94. I was observing from my September list at:

All observations are with my 18" f/4.5 Dob.

Here are the objects I observed, and my raw notes (NGCXXX = H400 list, NXXXX = H400-II list):

Abell 81    Cep    PN    32"    14.8    22 42 25    80 26 28
100X no filter! Very cool! To the W by 5' of bright star. Mostly round, annular, mottled, possible brighter edges to NW/W and SE.
N7129    Cep    OC    4.3'    9.3    21 45 12    65 46 23
7129 is faint and round with hints of neb. LBN 497 is very distinct and bright and may be NGC7133, 12' to the EENS. LBN 497 is involved in several brightest stars in the field. Nice view.
NGC 7142    Cep    OC    4.3"    9.3    21 45 12    65 46 23
Very close to LBN 497, this very noticeable OC is about 14' x 8' elongated NW/SE, with a distinct leading edge to the WSW. Many dim stars with the three brightest defining its eastern length.
N7139    Cep    PN    77.0"    13.3    21 46 08    63 47 31
Large and dim, but visible direct vision and without filter. With OIII and 12mm, round and mottled but not annular, central star very occasionally visible, possibly an extended halo to SSE and NNW. Guessing 2' diameter.
Abell 75    Cep    PN    56.0"    17    21 26 23    62 53 33
Visible unfiltered at 102X as a faint glow that could be mitaken as neb among some fraint field stars about 14' SSW of a distinct arc of 5 stars, bright of which points to the planetary. At 171X with OIII appears to have hints of annularity and perhaps an embedded star in the eastern portion. OIII dramatically improves view. With OIII at 294X, appears diffuse and about 2-3' in diameter, dimming evenly from a barely visible central star.
NGC 7160    Cep    OC    7.0"    6.1    21 53 48    62 36 00
Easy to identify the brightest pair of stars in the cluster, aligned NNW/SSE. Perhaps 30 or more stars NW/SE, with hints of nebulosity around the brightest center stars.
N7354    Cep    PN    36.0"    12.9    22 40 20    61 17 06
Small very bright planetary at 117X without filter. At 294X maybe 30', slightly annular, no central star. OIII at 280X shows clear small annulariety and possible very dim extensions WWNW/EESE.
NGC 7380    Lac    OC    12.0'    7.2    22 47 00    58 06 00
Roughly triangular shaped cluster with one apex leading to the W, the base a chain of stars clearly defining the eastern edge, many stars of similar magnitude. Nebula is seen in cluster without filters, but shows marked enhancement with fitlers. Nice cluster, with all sides being about 12' long.
Abell 79    Lac    PN    120.0"x90.0"    15.8    22 26 17    59 49 40
At 171X with OIII only the southern arc shows, running from E to W. Dim field stars to the E and W may make this object appear larger than it is. Maybe 3' in overall curved length.
N7245    Lac    OC    5.0'    9.2    22 15 08    54 20 00
Small tight group of many stars off tip of chain of four bright ones that fill the width of a low power field of view. Most all are same magnitude, except for the one bright one from the chain. Noticably brighter than rich Milky Way field, but not significantly brighter.
Abell 80    Lac    PN    2.7'x2.0'    15.2    23 34 45    52 26 12
Negative observation. Second night, with UHC and 171x, a slight brightening occasionally - from SAO 3983:310 go to SAO 3983: 190, then S same distance, then about 3' mostly E. Looking 3rd time, glow to E is extending N of star, as is glow now visible to W, looking at 293X with OIII filter. Look at spectral classes of stars in the edges of planetary to see how they would respond to film.
NGC 7296    Lac    OC    4.0'    9.7    22 27 57    52 18 58
Small, somewhat insignificant, not very interesting.perhaps 2 arcs of 5 stars each facing away from each other.
NGC 7243    Lac    OC    21.0'    6.4    22 15 18    49 53 00
Large, spread out, extended nne/ssw, not all that notable.
NGC 7209    Lac    OC    24.0"    7.7    22 05 12    46 30 00
Large, coarse, about 24 stars in a 24' area.
Abell 77    Cep    PN    76.0"x49"    16.4    21 32 10    55 52 44
Very threshold object at 171X with OIII and averted vision. Perhaps elongated.e/w. Medium size?
NGC 7128    Cyg    OC    3.1"    9.1    21 44 00    53 43 00
Nice group! Six stars in almost a Pisces configuration, one member, the SSE is brightest and most colorful.
NGC 7086    Cyg    OC    9.0"    8.4    21 30 30    51 35 00
Well condensed cluster, somewhat squarish, brighter stars to the center, a bit swiss cheesey with a few areas void of stars, several dozen stars.
M39    Aur    OC    21.0'    6.4    21 37 42    48 27 00
Perhaps 24 bright stars in a large coarse cluster.
N7082    Cyg    OC    24.0'    7    21 29 24    47 05 00
Fairly indistinct, in very rich Milky Way field. Lots of dim stars, with some background mottling that may be nebulosity. Dark lanes throughout the area.
NGC 7331    Peg    GX    14.5'x3.7'    9.4    22 37 04    34 25 00
Bright core, bright extensions on arms, about 14' x 3'. Tilted spiral, WWNW/EESE. Three companions visible on N side of galaxy.
HCG 92    Peg    GXCL    2.3'x2.1'    13.2    22 36 03    33 56 54
At 294X all five show. Three in along an E/W line, with two of them nearly merged and leading the third one, the other two are dimmer, one to the N, one to the S. Nice view.
NGC 7217    Peg    GX    3.9'x3.2'    11    22 07 52    31 21 33
Nice galaxy with very bright very stellar core. Could be mistaken for a planetary nebula if not studied carefully, or an unresolved globular if not for the bright stellar core. At 193X the core takes on a brighter small central area with the stellar center embedded. About 4' diameter and nearly circular. Perhaps slight elong SW/NE.
Abell 78    Vul    PN    13.8'    12.2    21 16 52    24 08 52
Not visible without OIII. At 193X dim glow 2'x2.5' NNE/SSW with a star offset inside to SE.
Arp 278    Peg    GX    1.7'x0.7'    14.4    22 19 26    22 29 53
Two galaxies at 171X appear almost as one but with two cores, NW/SE orientation. Cores are not much brighter than galaxies. Galaxies are bracketed by two nearly equal magnitude field stars. Galaxy to S is a bit brighter with tiny stellar core. 293X galaxies appear nearly connected, as if there is a slightly black "pinching" between them, and the dimmer N galaxy shows a very tiny intermittent stellar core with averted vision.
AGC 2666    Peg    GXCL    78.4'    13.8    23 50 54    27 08 00
Logged CGCG477-23, 477-21, MGC 4-56-23, KUG4-2348-269, MCG 4-56-19, NGC 7756, NGC 7768, NGC 7766, NGC 7767. All at 294X.
Arp 99    Peg    GX    1.3'x1.2'    13.2    23 15 16    18 57 41
All five visible. Three are bright and easy, two of which are spirals, perhaps face on, third is nearly edge on and long. Other two, the CGCG at mag 15.2 is difficult, at mag 16 the NGC galaxy is visually brighter. Nice group with fun range of difficulty.
Arp 170    Peg    GX    1.0'x0.6'    14.3    23 17 12    18 42 03
Awesome and extremely challenging group. Brightest 3 have 2 that break out well off a double star, with the third showing as a very faint glow moving the eye around with averted. A fourth member is visible (all now averted) taking single star through double, and out. Three others visible toward and near double star in line with three brightest galaxies - but this double is above original doulbe. Two of final three galaxies are merged, but too large to be a single galaxy according to their cataloged sizes.
Arp 212    Peg    GX    1.5'x1.3'    12.8    23 20 30    17 13 33
Evenly bright halo, with a brighter tight core, averted at high power shows occasional dim stellar core.
Arp 13    Peg    GX    2.5'x1.2'    11.6    23 00 03    15 58 50
Bright galaxy approx 2.5' x 1.2' with brighter core condensed to stellar point with averted. Extended mostly E/W.
AGC 2593    Peg    GXCL    28'    15.1    23 24 30    14 38 00
Only galaxies visible in cluster are NGC 7649 and IC1487, both nondescript, brighter one shows some elliptical shape but in an undetermined orientation.
Arp 150    Peg    GX    0.8'x0.5'    14.9    23 19 30    09 30 28
NGC 7609 is elongated E/W and very small, moderately bright. MCG 1-59-48 is seperated out and obvious. MCG 1-59-46 is visually almost attached to the NGC, but with averted vision at high power (294X) is can be distinguished, just off the S edge. Other MCG is to the SE.
Arp 298    Peg    GX    1.4'x1.0'    13    23 03 15    08 52 27
NGC 7649 extended WNW/ESE with 1.4' x .8' with intense stellar core and dim but distinct halo. Dim star involved in E edge of halo. IC 5283 dim and large without features, elonated in same direction as NGC, about same size, 1.2' to N of NGC. Nice contrast of two different galaxies.

1 comment:

Rick Hamell said...

The link about Hornitos California on GhostTown.Info has been moved, it now merged to