Most obscure object you've seen

[pgc hunter]

Perhaps for the sake of engaging in some visual DSO discussion, what is the most obscure/faint/hard/not well known object you've observed?

[stephenb]

Pluto in 1988. Only saw it twice, a month apart.

I've always wanted to catch a glimpse of some Terzan and Palomar globulars... one day may be... :rolleyes:

Great topic, by the way Sab :thumbsup:

[Varangian]

My toes after losing 23kg!

Uranus as a pale blue hazy blob jittering around in the ep. Not very obscure but I was looking for it but never expected to find it.

I'll be looking again at the end of this year.

[mozzie]

the horse head neb!!!!!!!!! i have seen it last summer faintly and averted vision my original thought was seeing it like all the images you see or even the head of black caviar!!! :lol::lol::lol::lol::lol::lol: only joking but yes seen faintly....also one day sirius b iv'e tried and tried!!!!!!!!!!!!!!

[mozzie]

i also tried the 3 faint p/n in m7 last night.not seen but i will get them !!!!! thanks to alex.....

[cometcatcher]

Yeah the horse head is tricky. Only saw it one dark night through a 10 inch f4.5 scope using a deep sky filter. Couldn't see it without the filter. All I saw was a dark notch, no shape to it or anything. Have tried on many other nights using different scopes without success.

[mental4astro]

I've managed one so far from home in my 17.5", Henize 2-295 (see chart below). It was my first "discovery" using the blinking technique. Brilliant how neat through the EP you don't see anything. Flick the OIII filter in front of your eye and a tiny ball pops up out of nowhere! Bloody awesome.

I suspect that the boarder shown below of M7 is smaller than the actual limits of M7 really are. Other charts I've seen have NGC 6444 wholely within M7.

The GC NGC 6453 is just visible in an 8" under urban skies (just). It makes for a nice wide field view with the core of M7, 6453 in the middle and 6444 on the other side.

The chart below is thanks to our mate NGCles. Ta Les.

[DavidU]

Apart from seeing my mother inlaw not talking once (only once) was Sirius B.

[cfranks]

For the last few months, the night sky!

[andyc]

Horsehead and Pluto perhaps for me, though neither are really 'obscure', just tricky!

The one that sticks with me though is seeing some of Barnard's Loop with just my eyes and a UHC filter on an unbelievably transparent -25C night in the Highlands of Scotland. It was the same night I saw the Horsehead (8" and UHC), the only time I've seen the Horsehead, and it was easy that night!!

[madbadgalaxyman]

I would vote for the Horsehead, as have others.

It requires a perfect sky, and the emission nebula vs dark nebula contrast on the two sides of the object is usually a matter of comparing a black section of sky with a section of sky which is a little less black!

I have also seen the brightest portion of Barnard's Loop, in 10x50 binoculars. Extremely hard, even in an excellent sky and with well coated optics.

[FlashDrive]

Now that is RARE ... :rofl: :rofl:

Flash :D

[mental4astro]

Neptune is another for me. It's only identifying feature is its excessively intense colour - too blue to be a star or planetary nebula, as it is stellar like in appearance too as it really doesn't have a resolvable disk.

It is currently not too far from Uranus in the sky. Uranus is brighter & with a greenish blue colour & a tiny resolvable disk. It is observable with 50mm binoculars from urban areas as it glows at magnitude 6.

[astroron]

Neptune Does have an Identifiable disc,that is how you can Identify it in comparison to a Star, and at 35 degrees separation is now quite far from Uranus.
Neptune rises at 21:57 and Uranus rises at 00:38 in the morning nearly three hours difference in time.
Cheers:thumbsup:

[stardust steve]

for me it was The Ghost of Jupiter planetary nebula. It was recommended by Suzy to check out and i was not disappointed. Even though i viewed it in moderate light polluted skies, moderate seeing through an 8'' Newtonian at moderately low power, i was still amazed in that knowing what it was i was looking at. Having to star hop my way to it via skysafari on the Ipad to track it down made the thrill of the chase even better. Can't wait to try and view it again soon under really dark skies:astron:

[stephenb]

Documented proof of this event?? 'cause I don't believe you :lol:

[Blue Skies]

Barnard's Galaxy in Sagittarius. I only went after it because it's in the Caldwell Catalogue. I wan't impressed, either with the the object itself or the choice of it for the catalogue! :rolleyes: Why pick something with such a low surface brightness...? I wondered that about a number of objects in the Caldwell cat.

But the planetary nebula Shapley 1 is a fave, one of those smoke rings. :thumbsup: Worth the hunt.

[pgc hunter]

My most obscure obs would probably be Uranus' moons Titania and Oberon, and Neptune's moon Triton with the 8" dob from my backyard.




The Caldwell catalogue is nothing more than a hand-picked list of random objects.

[ausastronomer]

Hi SAB,

Obscure can depend a lot on what aperture telescope you have available.

I have a few that I have clocked over the years, all of which are aperture dependant.

1. Observing Murrell 1 in the 25" Obsession at Coonabarabran. Murrell 1 is a faint planetary nebula discovered by my observing colleague Andrew Murrell in 2004. It is located in Norma and dimmer than 15th Magnitude. The Central Star is ~18th Magnitude. Despite several attempts I have been unable to observe it in a <20" scope under pristine conditions

2. Observing the Cone Nebula in my 14" SDM from Coonabarabran. This target is a threshhold target in an 18" scope under pristine conditions.

3. Observing Mars satellites Phobos and Deimos during the 2003 Mars opposition in Andrew Murrell's 20" scope from Brisbane Waters National Park.

4. Observing "The Bridge" between the two components of M51 in a 7" Starmaster Oak Classic, at the 2007 Texas Star Party.

5. Observing "the jet" eminating from M87 in my 18" Obsession from Coonabarabran.

6. Observing M33 naked eye from Timor Rock at Coonababran when it was located only 20 degrees above the horizon

7. Observing NGC 5128 (Centaurus A) naked eye from Franz Joseph Glacier in the South Island of New Zealand.

These are some that stick vividly in my mind and will remain there forever.

Cheers,
John B

[Paddy]

Great thread Sab. Interesting that obscure could mean the hardest to see or the most esoteric. My most obscure definite would be Henize emission nebula N70, a large supernova remnant in the LMC. Using my 16" under the dark sky at home it was quite a challenge. My other is the Aquarius Dwarf galaxy, but even though I checked against a DSS image, I still find it hard to believe that I saw it. Again 16" dob from Strangways.

[Blue Skies]

I came to the conclusion he picked them off photos. Disappointing, since I was under the impression he was a great observer. Some of them are nice gems but was disappointed with a lot of them.

[multiweb]

M16 through my bathinov mask. :whistle:

[ausastronomer]

Hi Jacquie,

Patrick Moore is more a lunar observer than a Deep Sky Observer.

To be truthful I don't know how much of an observer he is period. He has written a lot of books and his TV show "The Sky at Night" has run for several decades on the BBC for the simple reason he presents well to "the aristocrats" with his refined tones and monocle.

Looking at the omissions and inclusions in the Caldwell list it is obvious to most experienced observers that he has never observed a lot of the targets in the list. One notable exclusion is NGC 2808 which is a globular cluster in Carina and one of the most impressive globulars in the entire sky. It is indeed far brighter and more impressive than many of the Messier Globulars. Yet some how, Patrick Moore couldn't find a spot for it. On the other hand he has included some nondescript nothing targets which are very difficult in small telescopes.

Cheers,
John B

[Tamtarn]

My most obscure object was planetary nebula MyCn18 in Musca using my 12" dob. Was a few years ago must try again sometime!!
Barb

[pgc hunter]

Apparently the list was created as a compliment to the Messier catalogue, basically an attempt to include bright objects particularly those at far southern declinations missing from the Messier catalogue. It even includes the same number of objects. That would give me the impression that the list is aimed at beginners which makes the inclusion of objects like IC 1613 over other far brighter targets all the more bizarre.

[GrampianStars]

Aha! that explains it thought my scope needed throwing out.
haven,t seen the shape either. :(
& I have a very dark site....

Next November "Snake Valey" party a group effort may be in order :thumbsup:

[GrampianStars]

From my location the Andromeda Galaxy just clears the murky atmosphere
So... Her Globulars are well hidden :} M31-G001 is the only 1 I can identify (Hint get Bigger Scope) Others are at my limit ....

I also Love Ophiuchus...

NGC6240 galaxy
NGC6309 central star urgh!
NGC6572 central star urgh!
:rolleyes:

[Vegeta]

the most obscure object i've seen was an irridium satellite. I thought it was UFO until I realised it was a satellite. :)

[Blue Skies]

Thanks, but I was already active as an observer, had done the Messier list and receiving S&T mag where he first published the list and gave his reasoning. Which is why I was all the more disappointed with what he had chosen. It doesn't complement the Messier catalogue in any way in my opinion and some of the objects are far too challenging for a beginner. They challenged me and some of my even more experienced friends as well (and they are hard-core about their faint stuff!).

[BENHINSPETER]

Me too Ibrahim...last week, as I was checking out Jupiter, something flashed 3 times nearby.

Was most groovy...:thumbsup:

[leon]

I reckon whenever we turn our eyes upward we see something that is just amazing, it never ceases to amaze me, especially on a dark crisp clear night.

Leon

[wayne anderson]

Two obsure objects stay in my mind.
The first time i saw the horsehead nebula ic434, i remember the horse in the next field let out a neigh and trotted off just as i could make out the faint horsehead nebula.
Just last week i saw the 3 pillars in the eagle nebula M16 what i was more suprised about was that 3 complete newbies their first time viewing were able to see the middle pillar and described in detail what they saw.
I am always amazed by what we can see out there.
Wayne.

[barx1963]

The most obscure object/s I have managed are the group of ESO240-10, ESO240-11 and ESO240-13 all galaxies in Phoenix. The last one was right at the edge of visibility in my 12".

With regard to the Caldwells. I am still in the process of chasing down the last few that are visible. O'Meara book on the Caldwells contains a foreward by Patrick Moore in which he explains his reasoning. Firstly he admits he is primarily a lunar observer, but he makes the point that he has personally observed all these 109 objects. Secondly, he states clearly that they are not exclusively bright spectacular objects but include some dim and hard to get ones, but ones that are interesting from a scientific, astrophysical viewpoint. It is not a list of spectacular sights, nor is it a beginners list, it is a list of objects that one observers found interesting and maybe others will as well.

Malcolm

[pgc hunter]

Just checked these galaxies out on Wikisky and ESO240-11 is a very nice needle thin edge on spiral. How did it look in your scope?

[barx1963]

Sab

They were faint, but the needle of 240-11 was really obvious. The other were just smudges.

Malcolm

[mental4astro]

Thread resurrections seems to be a little rave at the moment...

Here's one to add to the mix, and a candidate for this coming September new Moon - 'Djorg 2'

Dojorgovski 2 is a magnitude 10 globular cluster, smack bang in the middle of the Cloud of Sagittarius. The kicker with it is it's behind the cloud, so it is heavily obscured, and difficult to make out from the surrounding 'noise' of the cloud. It is a really mind bend to make it out!!! It is certainly not a 'faint' target, but soooo tricky to make out.

It is very close to the lovely dark nebular B86, the Ink Spot, and the open cluster NGC 6520. The three are very close together (less than 0.8deg), so will all fit in the one field of view.

I first spotted Djorg 2 in July at Astrofest with my 17.5" & 12" scopes. I only found out about it because fellow IIS'er, Oleg, had Sky Safari with him and it showed Djorg 2 next to the Ink Spot that I had just finished sketching. Bugger! If I had known about Djorg 2 before starting the sketch I would have altered the sketch's arrangement to include it... Oh well, next time...

Mental.

[Allan]

I'll add the most distant object I've observed. 3C 273, Quasar in Virgo at 2.4 Billion light years.

[ausastronomer]

Hi Allan,

I have also observed 3C 273 a couple of times. While it appears as a dim star visually in telescopes due to its distance of over 2.4 billion light years, it is a very interesting object scientifically. It has an absolute magnitude of -26 which means at a distance of 32 light years (10 parsecs), or about the distance to Pollux, it would appear as bright as the Sun. It has 100 times the light output of the entire Milky Way Galaxy. That is one bright object.

Cheers,
John B

[Allan]

Nice one John, it's hard to fully comprehend just how much energy these things have.

[Terry B]

This is the list of silly objects
http://www.astronomy-mall.com/Adventures.In.Deep.Space/aintno.htm
Amazingly some have been observed.

[rrussell1962]

The thread seems to have deviated from DSO objects a bit. But one object (event) I won't forget is the transit of Venus. Lucky to have seen two and I know I will never see another, so certainly not repeatable for me. With a bit more planning I could have done better than a projection with the Astroscan though.

[mental4astro]

Hmmm, why just limit it to DSO's really - sorry Sab for your original intentions... :P

I've got a trio for you. On the Moon! Three craters - Armstrong, Aldrin & Collins. Challenge here is getting the lunar phase right and atmospheric conditions stable enough, particularly with Collins as its diameter is around 3km. Sounds big, and I guess a 3km hole is blooming big, but not so easy to see a 3km hole on the Moon from Earth...

The good thing about this trio is a really big aperture is not necessary. 5" should be enough - just. I've seen this trio only twice, the second time I only had fleeting glimpses of Collins & Aldrin. The other was barely any better. Spy out Collins and you are also very close to the Apollo 11 landing site.

[tonybarry]

Hi Rob,

The WSAAG crew at Linden Observatory in the Blue Mountains tried one evening / morning in December 2013 to nab IC434 (the Horse) using the Evans 30" dob (0.75m aperture).

It was not visible, despite no moon and a pretty dark site, and we tried for two hours. People had seen the Horse about ten years before at the same site, but the light pollution from Sydney has only gotten worse since then.

The consensus was that it is a doable target if the skies are dark enough. Otherwise, it is not a visual target.

Regards,
Tony Barry

[Tropo-Bob]

Messier 82 for me. It limps briefly to only 3 degrees above the horizon during the wet season. I saw the nearby M81 on first attempt, but it took me several more attempts and over 2years to find M82, in my 8inch Newtonian. That was in 1985 and I still rate it as my most difficult find with the equipment that I had.

And that ticked off my veiwing of the entire Messier collection (all 110) from the Cairns region.

[Steffen]

I nominate Sirius B. Anyone who's seen Alpha CMa B has my respect. At 10 magnitudes fainter than Alpha CMa A and only 10" apart this is a tough one to bag.

Cheers
Steffen.

[clive milne]

A solar prominence, naked eye. (During a total solar eclipse)

[Allan]

I didn't know this was a hard target, I'm not really into double stars. But Sirius B is always there when I look for it in my 12".

[pgc hunter]

lol didn't even know this thread was mine until I saw my nick under the title! I never specified DSO's though... so anything goes here :thumbsup:

My most obscure solar system objects which I observed are the Uranian moons Titania and Oberon in the 8". More difficult than Triton. Triton is actually brighter (m 13.5) than both Oberon (14.1) and Titania (13.9).

I have also seen Sirius B numerous times with the 8" dob at magnifications as low as 150x. I actually find Antares B to be significantly more difficult as it is much closer to the primary.

[glenc]

Paul and I did some observing last night with a 16". The most difficult object was NGC 6164 (top right of the star in the image). NGC 6165 to the lower left of the star is easier. Both of these nebula are in Norma. John Herschel discovered them with an 18.5" speculum reflector. It was 20' long and had no secondary.

[ausastronomer]

Hi Tony,

I have observed the Horsehead on dozens of occasions over a large number of years. There are some "tricks" to observing it which I will pass on.

Firstly the technical stuff. I believe and I am open to be corrected, that the correct target designation for the Horsehead Nebula is Barnard 33 (B33) which is the dark nebula made visible as the Horsehead, against the illuminated background of emission nebula IC434.

Now to observing it. First and foremost let me say there are some people who may never see it visually, irrespective of how dark the skies and how big the telescope. The reason for this is that IC434 emits its light in the far red end of the visible spectrum at near infrared wavelengths. Some peoples eyes are not sensitive enough at the red end of the spectrum to actually see the emission nebula IC434. If they can't see IC434 they can't see the Horsehead. This scenario was showcased a few years ago at IISAC, maybe in 2008. Andrew Murrell and I were running sky tours with the 18" and 25" 3RF Obsessions. A couple of people asked me if I could put the Horsehead in the 18" Obsession, which I did. I was not using a filter at this time and it wasn't all that difficult a target for me under pretty good skies (Linden isn't what I would call "pretty good", I would call Linden "fair"). Only about 1/2 the people observing at my scope could see it. One of the people who couldn't see it was a colleague and a very experienced observer. I couldn't figure out how I could see it so easily and he could not see it. I then asked Andrew Murrell to put the Horsehead in the 25" Obsession, which he did. In the 25" Obsession it was a simple target for Andrew and I without a filter and with direct vision. Our colleague and a couple of other people still could not see it in the 25" Obsession. I was somewhat baffled by this so I subsequently spent a lot of time researching why this might be so. What I came up with was different individuals own eye sensitivity to light towards the infrared end of the visible spectrum. I have discussed this subsequently with a number of experienced observers and they have agreed with me on this.

Some tips to enable you to see the Horsehead. I have observed it in scopes down to 10" aperture under pristine skies, although it's a very tough get in a 10" scope and it is a target you would normally chase in scopes > 14" aperture.

1) Dark Transparent Skies. You will struggle to see it anywhere within 100km of Sydney. I would call dark skies anything over 21.3 on a properly calibrated SQM. Places like Ilford, Bucketty, Lostock and some places in the Southern Highlands like Canyonleigh etc and several others, within reasonable proximity of Sydney, will be good enough. Places like Coonabarabran and Mount Kaputar will be better still.

2) Clean optics always help as they increase contrast and reduce light scatter.

3) Use a high light transmission and high contrast eyepiece having an exit pupil between 3mm and 5mm, 4mm is ideal. A 4mm exit pupil gives you the right contrast ratio. In other words in an F5 scope you would use about a 20mm eyepiece. In an F4.5 scope about an 18mm eyepiece and in an F4 scope about a 16mm eyepiece. A couple of mm in focal length either side of this will be fine. What you don't want to do for example is stick a 31mm Nagler or 27mm Panoptic in an F4.5 scope. The large exit pupil will reduce contrast too much. The eyepiece doesn't have to have a huge FOV. A medium FOV eyepiece between 45 and 70 degrees is probably best, but don't be scared to use a 17mm Nagler T4 for example if this is the focal length you need.

4) Try for the Flame or Tank Tracks nebula (NGC 2024) first, before you try for the Horsehead. The Flame Nebula is a little to the east of Alnitak (Zeta Orionis) and is illuminated by it. If the conditions and the telescope are not good enough to see the Flame Nebula, don't waste your time trying for the Horsehead.

If the Flame Nebula was doable then try for the Horsehead. It is located South of Alnitak and you need to push Alnitak just outside the FOV of the eyepiece. Pushing Alnitak out of the FOV greatly increases the contrast within the FOV.

5) A H-Beta filter is the filter of choice but if you do not have one don't despair. A wide bandpass UHC filter helps a lot. You need to use a UHC filter that has a high bandpass in the H-Beta line at 486nm and a bandpass in both OIII lines at 496nm and 501nm. My Astronomiks UHC filter works very well in my 18" Obsession. Not quite as good as my dedicated H-Beta filter, but not far behind it.


I think that just about covers it. Good Luck !!!

Cheers,
John B

[tonybarry]

Hi John,

Many thanks for your tips on observing the HH.

Your suggestion that the failure to observe was due to red sensitivity in the eyes of the viewers is intriguing. I shall share your post with other members.

You comment that the sky at Linden is now just "fair" rather than "dark" and yes, when objects are in the east and in the Sydney skyglow, it is a sad situation. To the north and west it is not so bad. But it is not pristine (to use your term). Still, it's WAY better than trying from UWS Penrith (closer to Sydney). On the plains, the light pollution is really serious.

Regards,
Tony Barry

[Terry B]

Jonn
Interesting description.
My only comment though would be that if you are using a H-beta filter you are filtering out all light except for the green coloured H beta line.
For this line it doesn't matter whether you eye is sensitive to the deep red of a H-a
I don't know how much H-beta IC434 emits but there should be some.

Terry

[N1]

For me, it's the Gegenschein and the Light Bridge connecting it to the Zodiacal Light.

[ZeroID]

Hamburger, NGC 5128. Went hunting for it to image and could only just see it through averted vision. Mind you, it was from my rather LP'd Ob site in Auckland.
I got enough frames to get an ok pic from it with some push in the processing.