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Old 22-09-2009, 02:43 PM
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Obs Report: Galaxies and Planetaries 19-20/9/09

One of my longest haul sessions to date, as it was actually clear all night for once. The day (Friday 19th) was clear, but just as the sun was setting of was mortified to see high cloud moving in, I just couldn't believe it. Lucky I checked the satpics, because it was apparent that the cloud would clear, and thus avoiding mass rage. Sure enough, by 9-9:30pm, all cloud was gone.

Seeing however had deteriorated greatly throughout the night, and by 3-4am stars were unfocusable even at 64x. Transparency however was fantastic, among the best I've seen.

Time: 7:45pm - 4:30am
Scope: 12" F4.6 dob
Seeing: 5/10, grading to 0/10
Transparency; 5/5

IC4846
PNe, Const: Aquila, Mag 12.7, Size 2"

A very tiny PNe but its HSB rendered it visible at 44x as a "star". It appeared stellar at all magnifications up to 353x, but considering the seeing, other field stars were being smudged making them look like "planetaries" aswell! Nonetheless, in moments of good seeings stars appeared as tiny airy disk while the PNe remained a tiny fuzzy orb.

Minkowski 1-59
PNe, Const: Scutum, Mag 13.3, Size 4.6"

Visible as faint star at 176x without filter. Being so tiny, I had to blink with OIII to seperate it from the field stars. Visible as a tiny patch of haze at 566x with OIII. Such magnification was overkill for the seeing at hand but it helped reveal the nebula's nonstellar form.

Minkowski 4-11
PNe, Const: Scutum, Mag 13.8, Size 21"

Suspected without OIII but the OIII filter at 283x revealed a small faint round glow with even surface brightness.

IC 4997
PNe, Const: Sagitta, Mag 11.6, Size 1.6"

An exceptionally tiny object, just 1.6" in diameter. Unfortunately, with the seeing deteriorating and the object being only 30º above the horizon, I couldn't pump up the magnification. Forms a "double star" with nearby mag 10.6 TYC1631-1973-1 . Without OIII at 44x, you couldn't tell which was the PNe! At 283x, while still largely stellar, the PNe exhibited a slight fuzz which helped differentiate it from its 'companion' star. Too small to resolve it into any form, but DSS images show two bipolar lobes with a bright central star.

NGC 7090
GX, Const: Indus, Mag 11.0, Size 8.1x1.6'

The edge on spiral appeared as an elongated NW/SE, sausage-shaped streak at 217x weakly concentrated towards center. I'd estimate the length to width ratio as around 4:1 as seen at the eyepiece. A faint star was seen superimposed onto the galaxy SE ofthe core.

ESO 240-10
GX, Const: Phoenix, Mag 12.6, Size 3.4x1.8'

1st of 3. Easy to find being located just 6' N of a mag 9.6 star. Quite bright, with hints of a stellaring in core at 217x. The core region appeared as a sausage shaped glow, elongated SE/NW, superimposed on a larger, fainter oval halo. A mag 15.15 star was seen at the northwestern edge of halo.

ESO 240-11
GX, Const: Phoenix, Mag 13.2, Size 5.6x0.5'

2nd of 3. Visible at 217x as a needle-thin streak of light oriented NW/SE, and is easy to find just 4' S of a mag 9.6 star. Relatively bright.

ESO 240-13
GX, Const: Phoenix, Mag 14.02, Size 1.5x0.9'

3rd of 3. Very faint and round at 217x. Located approx 8' E of -11.

IC 5332

GX, Const: Sculptor, Mag 10.6, SB 14.5, Size 6.0x5.8'

A large and very low SB (mag 14.5) face on spiral galaxy. Similar in size and structure to nearby NGC 7424, but this one is fainter. Easy to find using mag 7.2 HD221609 to the SW. At 176x I could just barely make out an extremely faint round patch of haze, located exactly halfway between a mag 10.1 star 5' to the SW and a mag 12 and 14.6 pair. I'd estimate this haze as about 1.5' across.

HICKSON 90

NGC 7176

GX, Const: Pisces Aust, Mag 11.3, Size 1.2x0.9'

NGC 7174
GX, Const: Pisces Aust, Mag 11.6, Size 2.5x2.2'

NGC 7173
GX, Const: Pisces Aust, Mag 12.0, Size 1.9x1.5'

This tight group of three galaxies was easily seen at only 44x as a hazy spot. At 217x, 7176 and 7174 could be seen 'attached' to each other, with 7176 appearing slightly brighter. 7174 was clearly elongated E-W and a stellar core could be seen within 7176. I increased magnification to 404x to get a clearer view of the 7176/4 pair, and I could now see that 7174 appeared semi-detached from 7176, i.e. not fully detached but there appeared to be a narrow dark void nearly splitting the pair. The western tip of 7174 curls slightly to the north. An extremely faint star was seen located midway between 7176 and 7173. Tried to look up the magnitude of this star on wikisky but it's not listed. Anyone can help me out here?
A fantastic little group and surprisingly bright aswell!

HICKSON 98

NGC 7783

GX, Const: Pisces, Mag 13.0, Size 1.3x0.6'

MCG+0-60-59
GX, Const: Pisces, Mag 15.0, Size 0.8x0.5'

Both galaxies seen at 283x. The northwestern member (NGC 7783) was the largest and brightest of the two, elongated E-W and a stellaring in the core was visible intermittently. MCG+0-60-59 lies just to the SE of 7783, seperated by a narrow gap. It appeared elongated NW/SE and is very faint. The group is located only 3' S of a mag 10 star, which interfered with observation somewhat.

------------------------------------------------------------

NGC 128
GX, Const: Pisces, Mag 11.8, Size 3x0.9'

At 176x this galaxy appeared strongly elonged N-S with a condensed core. DSS images show a strange looking thing with a peanut shaped central bulge.

NGC 125

GX, Const: Pisces, Mag 12.9, Size 1.7x1.5'

Faint, circular patch of haze at 176x located only 1' N of a pair of 13th mag stars. Small bright core.

HICKSON 7

NGC 192
GX, Const: Cetus, Mag 13.0, Size 1.9x0.9'

NGC 196
GX, Const: Cetus, Mag 13.6, Size 1.3x0.8'

NGC 201
GX, Const: Cetus, Mag 13.6, Size 1.8x1.4'

NGC 192 is the brightest member of this group. At 283x it appeared relatively bright, elongated N-S with a concentrated core. The northernmost member NGC 196 is smaller than 192 and also elongated, slightly fainter with a stellar core that could be held in view intermittently. NGC 201 was best seen at 353x, with a stellar core surrounded by a very faint round LSB haze. A 4th member, NGC 197 was not seen.

------------------------------------------------------------

UGC 439
GX, Const: Cetus, Mag 13.8, Size 1x1'

Quite easily picked up at 176x, appearing as a small, faint round patch of light. Better contrast at 283x. A mag 14.5 star is located approx 3' to the SE.

M33
GX, Const: Triangulum, Mag 6.36, Size 61x36.3'

The Triangulum Galaxy. HII Region NGC 604 clearly visible at 108x as a tiny hazy clump. A mag 11 star lies at its SE edge. A UHC filter only mildly improved contrast whereas the OIII actually ruined the view. The core of M33 could be seen as a large circular, mottled patch of haze and 5 faint stars to the south seem to "cradle" the core. The core appeared slightly brighter than NGC 604.

HICKSON 22

NGC 1199
GX, Const: Eridanus, Mag 11.5, Size 2.4x1.9'

NGC 1190
GX, Const: Eridanus, Mag 14.2, Size 0.9x0.3'

NGC 1199:- bright, with a round concentrated core at 353x. NGC 1190 was extremely faint, visible only intermittently at 353x with no shape or form detectable due to its extreme faintness. THe other 2 members, NGC 1191 and -92 were possibly detected aswell, but not with certainty.

-----------------------------------------------------------------

NGC 89
GX, Const: Phoenix, Mag 13.5, Size 1.2x0.6'

Quite easy to see at 283x, elongated NW-SE, slightly fainter than NGC 92 located 2' to the NE.

NGC 92
GX, Const: Phoenix, Mag 13.0, Size 1.9x0.9'

Slightly brighter than NGC 89 2' to the SW. Seen as round at 283x.
Part of a quartet of galaxies with NGC 87, 88 and 89. -87 and 88 not seen with certainty as I had no maps of their location and consequently unsure of exactly where to look.

NGC 1566
GX, Const: Dorado, Mag 9.8, Size 7x4.7'

A very nice spiral, clearly visible at 44x as an oval haze, but large and bright at 217x, large circular patch of haze increases in brightness towards the stellar core. Hints of spiral arms, a large knot adjacent the NW side of the core was seen- is this the northwestern arm?

IC 434/B33 Horsehead Nebula
Using the H-Beta Filter at 64x, it was easily picked up as a dark notch in the triangle-shaped IC434 cloud. Contrast wasn't particularly good, but it was nontheless quite easy to see.

NGC 1977
This is the reflection nebulosity just north of M42. Incidentally, the H-Beta filter greatly improved the view of this one over the unfiltered view! Visually, it was barely visible - akin to viewing a star cluster with a lightly fogged EP, but with the H-beta it was greatly enhanced. I was stumped - how can a reflection nebula be so much more obvious with a H-beta, of all filters? This one has me scratching my head thats for sure!

Last edited by pgc hunter; 22-09-2009 at 03:09 PM.
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Old 22-09-2009, 04:35 PM
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Quote:
Originally Posted by pgc hunter View Post
An extremely faint star was seen located midway between 7176 and 7173. Tried to look up the magnitude of this star on wikisky but it's not listed. Anyone can help me out here?
Great report pgc hunter, like the HH obs!

Re your query, if the 'star' is the one in attached pic (7176 with cross), then it's two essentially super-imposed stars, the brighter of which is USNO-B1.0 0580-1062422. Vis magnitude don’t know, although if I loaded enough catalogues no doubt I’d find out! B1=15.57, B2=15.38, R1=14.29, R2=15.38, I=14.36 given. Dim anyway!

Info & DSS pic from Aladin.

Cheers -
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Old 22-09-2009, 05:50 PM
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Great report pgc hunter, like the HH obs!

Re your query, if the 'star' is the one in attached pic (7176 with cross), then it's two essentially super-imposed stars, the brighter of which is USNO-B1.0 0580-1062422. Vis magnitude don’t know, although if I loaded enough catalogues no doubt I’d find out! B1=15.57, B2=15.38, R1=14.29, R2=15.38, I=14.36 given. Dim anyway!

Info & DSS pic from Aladin.

Cheers -
Thanks Rob! Yep that's the star I saw. Are the B and R values the red and blue magnitudes? I use wikisky to get the star magnitudes, but this particular one it just gives a bogus "99.9". The star USNOA2 0525-43607731 to the ENE of the one in question in your image appears to be almost the same brightness, according to Wikisky that one is Mag 15.6 so I'm assuming it'll be within a couple of tenths of that.

Btw, the galaxy you've crossed is NGC 7173.
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Old 22-09-2009, 08:43 PM
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Btw, the galaxy you've crossed is NGC 7173.
Oops, thought I punched in the other one! You should use Aladin - you can open a DSS image of the field you want, and by loading any number of weird & wonderful catalogues it'll tell you everything known about every single object in the field. Objects get ringed, and if you click on them the relevant catalogues entries pop up in bars below. For more information, you click on the object designation, and a separate window opens with the full catalogue information. Awesome, but I'm still in Preps as far as using Aladin goes...

http://aladin.u-strasbg.fr/

Cheers -
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Old 23-09-2009, 11:17 AM
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SOrt of getting the hang of aladdin here! But it only gives the blue and red mags for that star. Comparing it to other stars in the area, I'd say it's around mag 15.5.
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Old 24-09-2009, 10:55 AM
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I forgot to mention, all these observations were through what is practically mud!!!

After I packed it in, it turns out I've been observing with an absolutely FILTHY mirror!!! Apparently towards the end of the session, some of the dew that was accumulating somehow dripped onto the primary mirror, leaving two broad streaks as the water made its way down the surface. Now, these two streaks seemingly polished the mirror of dirt, making the affected surface look shiny new compared to the rest of the mirror! I was totally shocked at how a dirty a mirror I've been using all this time without even knowing it!

Here is a pic of the mirror in my 12" dob, you can see how much cleaner the bit is where the water ran down - you can see how much better the contrast of the reflection of the black surface is in the streaks and you can also see the "banks" of dirt pushed to the side by the water as it made its way down the mirror


A clean is in order this weekend! Can't wait to get it out under the stars afterwards. Last time I cleaned the mirror on my other scope, the difference in image quality was noticable, so I'm excited
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Old 24-09-2009, 02:29 PM
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A good clean may tidy up that little extra detail you need for your DSO's.
Whats the secondary like?
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Old 24-09-2009, 03:11 PM
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A good clean may tidy up that little extra detail you need for your DSO's.
Whats the secondary like?
Secondary looks alright.....a lot clearer than the primary i know that for a fact!

I've seen
stars to mag 15.9 with the mirror looking like this and the Horsehead aswell......ooohh I can't wait to see what it'll be like clean
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Old 24-09-2009, 11:45 PM
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Great report!

Hi PGC,

Another great report -- in fact probably the best I've seen. Not because it's long, or you saw a lot but because of the passion and enthusiasm it contains.

I'm not going to go through and compare notes on much except the ESO 240-10, -11 & -13 group in Phoenix. The only reason I've picked on them is because my observations of this group indicate that it obviously made a big impression on me at the time I observed it.

My observations of the group were from Bargo on 19 August 2001 an average night there with a ZLM of about 6.3 and seeing 5/10. 31cm f/5.3 --

x186 26' TF. ESO 240-10, ESO 240-11 and ESO 240-13 all lie in the same field.

PGC 71943 (ESO 240-10) Mag 12.6b Size 4.0 x 1.8'. This triplet are easily the highlight of the night!! -11 is in a pair with -10 with mag 10 * midway between. The eg's are aligned with respect to each other in PA 0 and seperated by 15'. -10 is fairly bright and a nice object. It has higher S.B than -11 but is more compact. 2' x 40" in PA 135, most of the visible halo seems to be taken up by a large moderately brighter core which brightens further to centre without an actual pip.

PGC 71948 (ESO 240-11) Mag 13.2b Size 5.3' x 0.5'. This is a wonderful eg and if it were in the northern hemisphere would be a showpiece object for large telescopes and well publicised. Alas it is a virtual unknown. Wonderful and stunning object. In PA 135, like a minature version of NGC 4565, even with a hint of a dust lane underlining the core on the SW flank. Lowish but reasonable S.B Fully 4.5' x 15", it has pointy tips and is shaped like a javelin, the boundary of the halo on the SW flank is much better defined than it's counterpart suggestive of a dark lane. There is no noticable core the eg grows slightly toward the axis in the inner 2/3rds. The tips are quite sharp. Really really beautiful!!

PGC 72038 (ESO 240-13) Mag 14.0b Size 1.3' x 0.8'. This is found about 20' SE of the above pair as a contrast. A very small very LSB round blob about 40" diameter with no central brightening. Faint to very faint.

I must go back and take a peek at this group in the larger aperture -- thanks for reminding me of it!

Yep, Mirror needs a tub!


Best,

Les D
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Old 25-09-2009, 11:40 AM
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G'day Les,
So I wasn't the only one surprised by the brightness of that ESO group! I totally share your sentiments, these galaxies are better than many NGC objects. Some of these more obscure catalogues certainly do hold some pleasant surprises. I'll have to revisit this group after cleaning my mirror!

Btw Les, where do you get your galaxy magnitudes from?

Last edited by pgc hunter; 25-09-2009 at 11:51 AM.
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Old 25-09-2009, 01:09 PM
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Hi PGC & All,

Quote:
Originally Posted by pgc hunter View Post
G'day Les,
So I wasn't the only one surprised by the brightness of that ESO group! I totally share your sentiments, these galaxies are better than many NGC objects. Some of these more obscure catalogues certainly do hold some pleasant surprises. I'll have to revisit this group after cleaning my mirror!

Btw Les, where do you get your galaxy magnitudes from?
Galaxy magnitudes (not so much the bright ones -- say brighter than 11th mag) are, put succinctly, somewhat of a pigs breakfast. You've got to think of the supplied magnitudes in many cases as being a bit like the "pirate's code" -- its more of a guide ... The "fainter" they are the worse it gets. Some are photometry at some strange passband, some are estimates and others are guesses based on their appearance in a survey plate. Most faint galaxies have not had accurate photometry. Those that have, it is infrequently a visual pass-band.

The ones in my little reports generally (almost always) are the ones from Megastar. They are often inaccurate or just plain old and out of date. When I make my log entry in Deep Sky (database software), I click on the text box containing this info in Megastar and place it in the field where the general comments go, before the description. I don't strictly need to because Deep Sky supplies all that info -- but that only works when looking at the log entry in Deep Sky. The magnitude in Deep Sky is not infrequently different from Megastar -- particularly the faint ones.

If I ever want to convert the comments in my log into a word doc it's easier to have it in that field -- just cut and paste and you've got something there at least.

The galaxy magnitudes provided by Megastar generally come from several sources. Some reliable, others not quite so reliable. Most of the brighter ones come from the RC3 (3rd Revised Catalogue of Galaxies), some come from the PGC (Principal Catalogue of Galaxies) from 1989 (one assumes you are familiar with that catalogue) and others from the old CGCG (Catalogue of Galaxies and Clusters of Galaxies) compiled by Fred Zwicky in the 1960's. On the other hand the PNe magnitudes are pretty recent and quite reliable. GC magnitudes are aanother pigs breakfast and are derived from a whole mish-mash of sources.

If I'm going to use a magnitude for a "critical purpose" -- ie publication etc I'll check it with NED or the NGC/IC project (assuming it is an NGC) and if there is a variance, I'll go with my "best pick" from NED.

Yep there is a lot of stuff outside the NGC (particularly in the southern hemisphere) that is quite bright and nice to look at. ESO 240-11, if it were in the northern hemisphere would be a "large 'scope showpiece". Obviously not good for small telescopes but in 12" and larger it is really beautiful. For those who like their galaxies faint and as skinny as Gandhi on a diet, (off the top of my head), take a look at IC 2531 in Antlia, NGC 7064 in Indus and for a real 12" challenge IC 5249 in Tucana ... Yum



Best,

Les D

P.S now that gives me an idea ...
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Old 25-09-2009, 04:13 PM
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^^ Thanks for the thorough explanation Les I use Cartes Du Ciel V3 and I downloaded the latest PGC/LEDA catalogue - It seems all the magnitudes in that are B mags. When I look up the corresponding B mags in NED, there is often a discrepancy between it and CDC of up to a whole magnitude, for the same galaxy, but more commonly a few tenths. Would you say that NED is the better/more accurate or CDC? With NGC objects it doesnt matter as NGC-IC provides V mags for most of those.

I just checked out IC2531 on sky-map.org....niiiice! It's a fun-size version of NGC 891 It's on my menu as soon as Antlia makes a comeback. There's another nice needle ESO435-019 less than a degree to the south. IC5249 is nuts, DSS images show an *actual* needle with barely a hint of a bulge or anything. There's also IC5244 about a degree to its north, it's a textbook perfect spindle with sharp pointy ends on DSS images. Another nearby gem is IC5250A/b, two galaxy cores touching each other.
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