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drawings of obscure summer objects

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#26 CarlosEH

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Posted 29 November 2009 - 12:44 PM

Yann,

Two other interesting deep sky targets for us to learn of. MC 7406 does appear to look like a tadpole. The interacting galaxies (NGC 6255 and HS 1653+3634) are interesting and are a good target for large aperture instruments. Thank you for sharing them with us all.

Carlos

#27 Jeff Young

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Posted 01 December 2009 - 11:40 AM

Yann --

Excellent sketches of some very interesting objects! :waytogo:

Of them all, I've only Arp78 (NGC770/2) logged. My sky conditions were a bit worse and I only managed to make out the stub of the brighter arm:

NGC772 I-112 1/23/2009 19:30 UT; Pickering 3, NELM 5, SQM 20.3
400mm Mak-Cass @ 225X

Eccentricity immediately apparent, but it takes considerable study to identify orientation. Some knotting in core, giving the appearance of a broken up cometary nucleus. Tried a big exit pupil (55Pl), but more magnification seemed more effective. Dark lane to NNE of core, other edges indistinct. Couldn't really make out the asymmetric arm.

Companion galaxy (NGC770) nearly easier, although it's not much more than a fuzzy star.

Posted Image


Keep those sketches coming!

Cheers,
-- Jeff.

#28 yann pothier

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Posted 01 December 2009 - 01:30 PM

Carlos and Jeff, thanks for your comments !

Jeff> Good sketch of yours ! I don't own a SQM but I guess (from neighbours under similar skies that it could be over 21.0 most of the time, so yes, my conditions were better).

I forgot to say that I always propose my sketches with north up (and west right being a newtonian user...)

clear skies, Yann

#29 CarlosEH

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Posted 01 December 2009 - 03:55 PM

Jeff,

An excellent observation of Arp 78 (NGC 770/72). This is a very interesting par of galaxies. I found an image of the pair obtained by the Calar Alto 1.23-meter reflector. Your observation agrees very nicely with it. Thank you for sharing it with us all. I look forward to your future observations.

http://www.allthesky...xies/arp78.html

Yann- I look forward to your future observations as well.

Carlos

#30 yann pothier

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Posted 04 December 2009 - 08:22 AM

In the middle of the night and still on chart #114 of Uranometria (1st edition) in the heart of Hercules, I was about to move to NGC 6274 paired with its subtle companion LEDA 59381.

This interactive couple more than 500 millions light-years away is worth a look : the main galaxy is seen face-on and the companion is edge-on ! The large brightness difference makes it difficult to spot both galaxies at the same time.

Posted Image
T445x271-426

LEDA 59381 is "very small, extremely faint, seen less than 5 % of the observing time at 333x (glimpsed 2 or 3 times in a 15 minutes survey); elongated NW-SE with ill-defined edges and of homogeneous brightness; about 20”x5” ; with NGC 6274 16” to the NNW (center to center)".

NGC 6274 is "small, extremely faint, seen 25% of the observing time at 125x and still visible at 426x; round with ill-defined edges and homogeneous brightness; about 30” in ø".

Yann

#31 CarlosEH

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Posted 05 December 2009 - 06:29 AM

Yann,

An extremely faint target for your instrument. This is a challenge for us all. Thank you for sharing it with us all.

Carlos

#32 yann pothier

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Posted 11 December 2009 - 09:52 AM

Between 11:30 and 11:55PM UT, I scrutinized patiently the galaxy NGC 7252 in Aquarius (celebrated Atoms for Peace), but even if its surface brightness seemed irregular, it was far from the distorted shape it harbours on images. A larger aperture should help in locating more steadily the clumps visually...

Posted Image
T445x271

My log book describes : "at 271x, small, medium brightness, seen 50% of the observing time at 80x, and still visible at 426x; round, about 1.1' in diameter, with ill-defined edges and s somewhat brighter center; clumps are suspected but not for sure."

#33 CarlosEH

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Posted 13 December 2009 - 10:17 PM

Yann,

An excellent observation of NGC 7252 in Aquarius. This appears to be an interesting diffuse galaxy. Thank you for sharing it with us all.

Carlos

#34 yann pothier

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Posted 14 December 2009 - 10:43 AM

My last object for the night (well, not really the latest beacuse I also worked about an hour on M33, a multi-session object I will report about later) was UGC 12342 in Pegasus. This beautiful result of interacting galaxies is more than 350 millions light-years distant and offers in the eyepiece a strong boomerang-like pattern. Really, both galaxies are melting with an apropriate angle as you can check on the drawing.

Posted Image
T445x271-333

I described the couple as the following: "at 271 & 333x, small nebula, extremely faint, seen 25% of the observing time at 80x and still visible at 426x; V-shape seen about 10% of the observing time, with diffuse edges and homogeneous brightness; the "boomerang" is 40” long, 11” wide, pointing ENE and its extensions are to the S and NW ; the NW galaxy seems a little larger; mag.8 star 7.5’ to the SSE."

see you next time for the 3rd night !

#35 yann pothier

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Posted 15 December 2009 - 09:02 AM

My 4th session (not 3rd as erroneously stated above) started with a planetary nebula I thought I've never seen, and I only realised later that I did in fact observed it in 2006! The conditions were excellent though a slight halo surrounded Jupiter (warmer temperatures than normal in France at this time, 18°C at the beginning of the night...) and occasional ligthning from nearby Italy took place sporadically and flashed the sky brightly.

It was also the first time I used some new charts for visual magnitude estimates naked-eye in UMi I had worked on. Before this night, I thought my refering star to be of 6.31 but in fact it is 6.6 (visual, not V), and my "new" limit was 6.9 on this particular night. Under normal circumstances, my observing site allows me to reach 6.6 with averted vision between 25 and 50% of the observing time and 6.9 about 10%.

So, my first target was Abell 62 (PK 47-4.1) in Aquila, and it was only suspected with the filter. At times, I thought I could hold it steadily but I have to be conservative for the interference filter (OIII here) sometimes blurs "faint stars" into faint "false" nebulae. I noticed a brighter rim along the S border but it stands nearly exactly on a small chain of faint stars (visible without filter), so it makes me doubt. An argument in favor of this observation is that this rim was already noticed in 2006. In this session, I also observed the inside nebulosity of the object that I had not drawn in 2006... On the whole, I still have doubts about this object and would welcome any comments of observers who have seen (or not) this object.

Posted Image
T445x271 (for the stars) x125+OIII (for the nebula)

My notes in 2006: "22/08/2006, 22:50TU, at 271x, medium sized PN, extremeley faint, seen less than 5% of the observing time, from 103 to 271x; oval with ring portions with ill-defined edges, about 104”x47” NW-SE, homogeneous and faint stars are spreaded across the object and they distract the observer from the nebula; UHC & Hbeta filters give no gain, OIII a small contrast gain; mag.10 star 2’ to the NW."

My notes in 2009: "22/08/2009, 22:10TU; at 271x for the stars and 125x+OIII (Lumicon) or 100x+OIII (Baader) for the nebula, medium-sized PN, extremely faint, seen about 10% of the observing time at 125x & still at 271x ; round with ill-defined edges, quite homogeneous but a little brighter along the S and SW borders; a lot of internal stars, about 2.4’ in ø (144”) ; UHC gives a small contrast gain, OIII a good one, and Hß none ; mag.10 star 2’NW."

See you next time for a spectacular cluster of galaxies !

#36 yann pothier

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Posted 18 December 2009 - 10:06 AM

My second target for the night was not best placed in the sky at 00:00 UT, well after meridian, but I really wanted to have a look at it through the eyepiece. Abell 2199, a cluster of galaxies, stands in Hercules and contains a giant central member : NGC 6166. With a thorough visual inspection, this cluster was a gold-mine of faint galaxies scattered around the giant.

I will certainly return to it with a more precise field-chart because I had badly prepared my visit and I almost surely missed some faint members.

Posted Image
T445x271

For the purist, here are the descriptions of each member :
NGC 6166= medium-sized galaxy, faint, seen 75% of the observing time at 80x and still visible at 426x; oval NE-SW with diffuse edges and a brighter center; about 1.0’x0.8’.

PGC 58244= very small galaxy, extremely faint, seen about 10% of the observing time at 271x and visible between 154 and 426x; round with diffuse edges and homogeneous brightness; about 18” in ø ; located 3.2’WNW from NGC 6166.

PGC 58261= very small galaxy, very faint, seen 25% of the observing time at 271x and visible from 125 to 426x; round with diffuse edges and homogeneous brightness; about 10” in ø ; located 1.3’SW from NGC 6166.

PGC 58262= very small galaxy, very faint, seen 25% of the observing time at 271x and visible from 125 to 426x; round with diffuse edges and homogeneous brightness; about 15” in ø ; located 2.0’S from NGC 6166.

PGC 58275= very small galaxy, extremely faint, seen about 10% of the observing time at 271x and visible between 154 and 426x; round with diffuse edges and homogeneous brightness; about 10” in ø ; located 2.5’SSE from NGC 6166.

PGC 58276= very small galaxy, extremely faint, seen about 10% of the observing time at 271x and visible between 154 and 426x; round with diffuse edges and homogeneous brightness; about 10” in ø ; located 4.2’SSE from NGC 6166.

PGC 58277= very small galaxy, very faint, seen 25% of the observing time at 271x and visible from 125 to 426x; round with diffuse edges and homogeneous brightness; about 18” in ø ; located 4.9’SSE from NGC 6166.

PGC 58278= very small galaxy, extremely faint, seen about 10% of the observing time at 271x and visible between 154 and 426x; oval NNNW-SSSE with diffuse edges and homogeneous brightness; about 18”x9" ; located 5.6’SSE from NGC 6166.

PGC 58279= very small galaxy, extremely faint, seen about 10% of the observing time at 271x and visible between 154 and 426x; round with diffuse edges and homogeneous brightness; about 10” in ø ; located 7.0’SSE from NGC 6166.

PGC 58299= very small galaxy, extremely faint, seen about 10% of the observing time at 271x and visible between 154 and 426x; round with diffuse edges and homogeneous brightness; about 15” in ø ; a mag.15 star is 22" to the SE; located 1.7’E from NGC 6166.

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A cluster of galaxies is always enjoyable, so much that one can forget about those fainter members just at the limit of perception... One also has to be well organised to record brightness, position, shape, etc. of each galaxy : not easy! Moreover, the fainter smaller galaxies may mimic stars with a non-cooperative seeing, that makes the observation more difficult (this was not the case here as the stars were still point-like at 271x).

Another couple of galaxies next time...

Yann

#37 yann pothier

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Posted 22 December 2009 - 10:20 AM

Another galaxy pair, merely a carbon-copy of NGC 6835 & 6836 described above, consists of NGC 7342 et NGC 7345. It was rather the latter that got me into observing these, as it was edge-on (I especially like those thin galactic pieces). They are about 60 millions light-years apart and though a global distance of 330 millions LY, they should not interact strongly at the moment...

Posted Image
T445x271

My notes are only about 7345 (7342 was not my main goal): "at 271x, very small, faint, seen 75% of the observing time at 80x and still visible at 426x; seen edge-on, elongated NE-SW, with well defined borders and a brighter center; about 1.0’x0.2’ (62”x16”) ; with NGC 7342 quite diffuse 7.0’ to the WSW (and a mag.14 star to its immediate W)."

see you next time for the last drawing of this 4th session (those tired would be happy to know that there were only 6 sessions last summer...! :cool:)

Yann

#38 yann pothier

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Posted 23 December 2009 - 08:44 AM

As a last target for this 4th session, I had choosen a distorted galaxy of Pegasus : NGC 7292. This irregular galaxy of "IBm" type is not symetric at all at the eyepiece, and I eventually noticed its sharp southern edge.

Posted Image
T445x271

My logbook says : "at 271x, small to medium sized galaxy, medium brightness, seen 100% of the observing time at 80x and still visible at 426x; oval NW-SE, with ill-defined edges and a brighter bar or central axis; about 1.3'x0.9' of overall size; a stellar knot (or faint star) is at the SE limit, and it adds to the impression of greater density on this side of the object; the central "bar" also have a brighter side here and it ends with a squared extension (facing S)."

At 01:30UT, I had finished with NGC 7292's drawing and M33 beeing high above horizon, I returned to it in order to complete a multi-dession drawing I will propose soon.

see you next for the 5th observing session that contained one unique object!
clear skies, Yann

#39 Jeff Young

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Posted 23 December 2009 - 01:45 PM

Nice sketches, Yann. Abell 2199 looks like particular fun.

-- Jeff.

#40 CarlosEH

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Posted 23 December 2009 - 02:02 PM

Yann,

An excellent series of galaxy observations. A very interesting variety of galaxies. Thank you for sharing them with us all.

Carlos

#41 yann pothier

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Posted 01 January 2010 - 01:17 PM

The 5th session (28 to 29th of august) was too quickly spoiled by clouds, although it had greatly started with good transparency and medium seeing conditions. But the greater humidity percentage than the other nights was a forerunner sign of the coming cloud cover...

I still had the time to locate and draw NGC 7212 in Pegasus, the result of progressive fusion of 3 galactic bodies (among which a Seyfert active nucleus). Indeed, this galaxy looks irregular at the eyepiece and the Seyfert nucleus stands out prominently: I should have tried the OIII filter !

Posted Image
T445x271

My notes says: "at 271x, small, very faint, seen 50% of the observing time with averted vision at 80x, and still holds at 426x ; oval NE-SW, with diffuse limits and a stellar nucleus of mag.15 (the rest is homogeneous) ; about 0.7’x0.3’ ; a small nebulous hook is seen about 10% of the observing time with averted vision at 333x leaving the NE extension at right angle to the NW [it is the companion galaxy UZC J220702.4+101414] and it is about 0.4’x0.2’ ; the all nebulous "thing" is surrounded by 2 stars of mag.15-16 less than 20” from the ends."

see you next for the last summer session,
Yann

#42 yann pothier

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Posted 04 January 2010 - 02:39 AM

Here the begining of the last session of my summer holidays :(

The night offered excellent conditions along with colder temperatures (more usual for this place and season): visual magnitude limit in UMi of 6.9 (10% of the observing time with averted vision), pinpoint stars until 271x. Still, a faint halo of light around Jupiter was noticable, because of a high thin layer of clouds (winter nights are less subject to thiskind of degradation, and this trouble was particularly ennoying this summer).

From 00:00 to 00:50 UT, my first target was a typical edge-on galaxy : UGC 12281. It is also referenced in the "Flat Galaxy Catalog" under #2441, and visually it really appears very long and so thin: the elongation/thickness ratio is about 10...

Posted Image
T445x271

My notes : "at 271x, small, extremely faint, seen 50% of the observing time with averted vision, at 80x and still visible at 271x; thin ray of light, elongated NE-SW, with diffuse edges and homogeneous brightness; about 2.0’x0.2’ ; mag.15 star stands 13” from the NW edge of the SW extension, near its end."

I recommend this one : not really bright but a true ghost's hair !

Yann

#43 frank5817

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Posted 04 January 2010 - 11:47 AM

Yann,

I am very impressed with all these fine faint deep sky targets you have posted here. Excellent work. :bow:

Frank :)

#44 yann pothier

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Posted 05 January 2010 - 02:36 AM

Many thanks, Frank !

#45 yann pothier

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Posted 05 January 2010 - 08:23 AM

It was 01:15 UT when I pointed a small galaxy group around NGC 7609, compact enough to be part of Hickson's catalog under #95. Located in Pegasus (a real paradise for galaxies) and about half a billion light-years distant, the participating 4 galaxies are more or less easily separated with the 17.5" dobsonian. With some tenacity, I managed to resolve the all group even if the shape and orientation of galaxies are very difficult to determine.

Posted Image
T445x271

My notes for the all cluster : "at 271x, small group of 4 galaxies gathered in a ø2' area, triangular in shape with the brightest galaxy at the N corner."

And for individual objects, from right to left on the drawing (right ascension) :
HCG 95c (LEDA 71074) : at 271x, very small, extremely faint, seen about 10% of the observing time with averted vision at 200x and still visible at 426x ; oval NW-SE ?, with very diffuse edges and homogeneous brightness ; about 10”x7” ; located 1.2’SW from NGC 7609 [the main galaxy].
NGC 7609, HCG 95a (LEDA 71076) : at 271x, small, faint, seen 100% of the observing time with averted vision at 80x and still visible at 426x ; round, with very diffuse edges and homogeneous brightness, and a mag.14 stellar nucleus ; about 33” in ø.
HCG 95d (LEDA 71077): at 271x, très petite, extrêmement faible, vue VI3/200x et jusqu’à 426x ; ovale NO-SE, aux bords très flous et de brillance homogène (type a) ; environ 13”x10” ; située presqu’au contact de NGC 7609, à 26”SE centre à centre.
HCG 95b (LEDA 71080) : à 271x, very small, very faint, seen about 75% of the observing time with averted vision at 80x and still visible at 426x ; round (or slight elongation seen about 5% of the observing time at 271x), with very diffuse edges and homogeneous brightness ; about 16”x7” NW-SE ; located 1.4’SE from NGC 7609.

Nice group, really !

Next time a last object I may have invented (averted imagination?) !
Yann

#46 yann pothier

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Posted 07 January 2010 - 03:00 AM

So, last (and least unfortunately) object of this last session, Kohoutek 1-20 (PK 110-12.1) was a half-failure (or half-success as you prefer). I was enough confident at the end of my field drawing at 03:00UT to believe I had suspected its vanishing bubble less than 5% of the observing time and only through UHC and OIII filters that gave a subtle contrast gain. I admitted that it was very difficult to sort out from the background sky.

Now, after comparing with images of the area, I have a doubt : 2 faint stars are located at the place where I have drawn the nebula (the object should be a little more to the SW)... Nevertheless, I carefully observed with and without filters, and if those faint stars had been "blurred" by the filters (at the verge of detection) mimicking a nebula, they would surely have been seen without filter !?

So, I have to go back to this object, knowing the existence of the 2 faint stars, to sort the real stuff from the imagined one!

Posted Image
T445x200 (rough drawing)

My note "S, eF, VI5+/154-200x, ø=23", bmd, homo, UHC=OIII=+, Hß=0" meaning "small, extremely faint, suspected less than 5 % of the observing time at 154 & 200x, with UHC and OIII filters; round, about 23" in ø, diffuse edges and homogeneous brightness; UHC & OIII offering a small contrast gain, Hbeta of no use."

This is the end of my summer nights, but I will post soon another long business work on M33 that I nearly finished this summer.

clear skies to all in 2010,
Yann






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