24 replies to this topic

[FernandoPrz]

I live about 39N. I managed to observe Omega Centauri a few times some 10 years ago. But I had no chance to see it again recently.

 

At 39N, this object goes barely 3-4 degree about perfect plain horizon at its best. Along these years I managed to locate a very good observation site, not very far away from home, in order to be able, again, to observe this cluster. This site is a 3100ft mountain top, about 1 hour drive from home, with perfect view along South. The site darkness can be rated about B2, I think.

 

But, even with this wonderful site, weather and the Moon should help in order to be able to see Omega Centauri again. No good luck for the past few years (right time to see it is just beginning of Spring).

 

Until yesterday. A powerful high pressure system with ultra dry air entered Spain from high latitudes. No moon. My barometer went crazy ... 1035mb !! ... and many hours of stable weather in the forecast without wind. Even temperatures were perfect.

 

So I took two binoculars pairs (7x50 and 15x70) and drove 1 hour in the middle of the night headed to the selected observation site. I arrived about 30 minutes before the culmination time, but the sky was so good there (very dark, no wind, very dry and 10C temperature) that I could easily catch Omega Centauri with just handhelds 7x50 at first try.

 

Later, I try the 15x70's mounted on tripod and the view was amazing, just a few degrees about some very distant mountains that defined my horizon there. I could resolve individual stars even with that small magnification and being so low.

 

But the show didn't stop there. I realized that Centaurus A (a large bright exotic galaxy) was near Omega Centauri, just a few degrees up. I tried it and, again, success, with both 7x50 and 15x70 ... barely 8 degrees about the horizon, another amazing view and first time I observe this beauty.

 

The sky was so dark that the Gegenschein was a huge distraction just North of Centaurus, somewhere in Virgo. Second time in my life that I see it.

 

I always thought about Omega Centauri as some object that can be glimpsed from these North medium latitudes, but yesterday proved I was wrong. It's a really amazing object at the right time when there is cooperation from weather and the moon. And Centaurus A is an unexpected powerful companion to Omega Centauri.

 

Regards.

Edited by FernandoPrz, 12 April 2024 - 01:41 PM.

[auroraTDunn]

I'm so impressed an jealous. I used to observe it when I lived in Tucson and still can;t forget not just the first time I saw it with my little handmade 6" but the first time I saw it at a star party with a 20" WITH a 2" eyepiece. It was the eyepiece that really brought it to magical life. All these decades later and I still drool when I think of seeing it that night!

Now in Colorado there's not a chance in heck I could possibly see it unless maybe I was on top of a couple of different fourteeners  (4200+m peaks). But now that you have me thinking about it, hmmmmmm.

[MrsM75]

That is awesome! Sir,

may I ask what your dark site observing place sky Bortle and SQM? If you can see it with binocular then your observing site must be very dark as Omega is so low where you at, you looking through bunch of atmosphere.

 

eta: Sorry reread your post you said your observant site up in the mountains it Bortle 2, well Bortle 2 is very dark.

 

 

I live in 34 degrees North, Omega get 8 degrees altitude here culmination. I observe it from home sit outside right where I live look down South, and I'm in Bortle 7.8 with 18.9 SQM.

 

I have zero problem see Omega here everynight right where I live, it just I only see it as  Big Grey Glow. I cannot see anything more out of than a Big Grey Glow.! And I have small aperture scopes.

 

This sketch I found in Google is what I saw in my Mak, minus the stars in Omega, I do not see any stars in Omega let alone, resolve stars. It look just like this sketch it basically a Big Grey Glow. Minus the bright stars in it in this sketch.

 

Edited by 34degN, 12 April 2024 - 06:59 PM.

[Coldwarwarrior]

I guess I'm lucky where I am at -27S, Omega is high in the sky and an easy naked eye object, even in a small 6" scope you can begin to resolve individual stars,  Centaurus A is a little fainter, but still easily identified in a pair of 10x50s, in a small scope in a dark sky you can see the center dust lane in a larger scope its even more apparent, I observed it once through a 20" dob and it was quite remarkable.

[Nankins]

I live at somewhere between 40 and 45 degrees north, so Omega Centauri is almost a horizon skimmer here.  I've tried once and didn't see a thing, presumably due to some light pollution that is in the south.  We have trees along our southern horizon, and Omega actually sits at it's highest above the treetops a degree or two.  Centaurus A is slightly higher, but I can't see it at all.  Did get as far south as Iota's Ghost, the little galaxy near Iota Centauri, so that was cool.  But I have a place I can go that has visibility to the horizon.... Was just out there last week and I kid you not about a third of Vela was easy to see for those of us who knew where to look and what it looks like.  I could likely get Omega Centauri and Centaurus A from out there.  

 

Glad you have been able to have such luck seeing it. 

[Oldfracguy]

Yes, at this time of the year for those of us in the Northern Hemisphere, Omega Centauri can be seen best around Midnight when it is due South at its highest.  In fact, I caught a decent view of it two nights ago under dark skies far away from the city from 33° N when it was about 10° above the Southern horizon.  It is a real treat to see, but it takes a night of steady air with decent seeing as we are looking through lots of atmosphere at that low angle of elevation. 

Edited by Oldfracguy, 13 April 2024 - 07:06 PM.

[MrsM75]

How do you see it though Sir Oldfracguy, do you see stars in Omega?

 

I see it here every night observing right at home in my 34,000 population town. BUT I only see Omegas a Big Grey Glow.! I don't see any stars in it, let alone resolve any stars. Just a big grey glow.

Edited by 34degN, 13 April 2024 - 07:25 PM.

[MrsM75]

And if those who observe it from home right at home sky like me, I have one tip. Here is the map of Centauri I can see all those stars I circled naked eyes here in my sky, and Omega is 8 degrees altitude here.

 

My tip is, you HAVE to see Zeta Centauri naked eyes in order to see Omega in your scope, due to how low Omega is you looking through tons of atmosphere, so your sky need to be transparency enough that you can pick up Zeta Centauri naked eyes.

 

I see Zeta Centauri naked eyes here, I got Zeta star in my eyepiece and I pan to the right and right and you will hit Omega. With even that Omega is just a Big Grey Glow to me, due to it so low altitude, so you do need a dark sky too.

 

Edited by 34degN, 13 April 2024 - 07:24 PM.

[Oldfracguy]

How do you see it though Sir Oldfracguy, do you see stars in Omega?

 

I see it here every night observing right at home in my 34,000 population town. BUT I only see Omegas a Big Grey Glow.! I don't see any stars in it, let alone resolve any stars. Just a big grey glow.

This last time a few days ago I was able to see a large ball in the middle, but only a few stars around the outer periphery.  I was using an AT125EDL, and the air was getting pretty moist by Midnight.  I was in the desert in far Eastern San Diego County, and the glow of a border town over the low hills tended to create a little "light pollution" when viewing directly South.

 

Last year in mid-May from a higher elevation in the nearby mountains shielded better from urban light pollution, about 5,000 ft., I has a much better view.  That time I was using a C8, and also a 6" f/6 Newtonian.  I could definitely see stars around the core of Omega Centauri.  One thing those SCTs do very well is globular clusters.

 

Also, being under a dark sky is worth more than extra aperture.  If you are able to get out away from the city under reasonably dark skies, you will be amazed at how many more stars you can see in open clusters such as M37 in Auriga, and globular clusters at higher magnifications.

[FernandoPrz]

That is awesome! Sir,

may I ask what your dark site observing place sky Bortle and SQM? If you can see it with binocular then your observing site must be very dark as Omega is so low where you at, you looking through bunch of atmosphere.

 

I don't have a SQL myself.

 

In the past, I have been observing at that site with some other guys who had SQM and I remember seeing SQM readings around 21.6-21.7. M33 is a naked eye direct vision object there. This is not my main observing site (too cold most nights).

 

But altitude and atmosphere stability are paramount to being able to see objects so close to the horizon. I always try to observe (even regular observations) with pressure (at sea level) above 1020Mb, if it gets past 1030Mb then it's time to try really difficult things like Omega Centauri.

[Oldfracguy]

I don't have a SQL myself.

 

In the past, I have been observing at that site with some other guys who had SQM and I remember seeing SQM readings around 21.6-21.7. M33 is a naked eye direct vision object there. This is not my main observing site (too cold most nights).

 

But altitude and atmosphere stability are paramount to being able to see objects so close to the horizon. I always try to observe (even regular observations) with pressure (at sea level) above 1020Mb, if it gets past 1030Mb then it's time to try really difficult things like Omega Centauri.

Fernando, puede ud. viajar a las Islas Canarias?

[FernandoPrz]

Fernando, puede ud. viajar a las Islas Canarias?

He estado en la isla de Lanzarote (la más cercana a África) pero había contaminación lumínica, hay muchísimo turismo y son islas pequeñas.

 

La única isla que tiene cielos realmente oscuros es La Palma, la más lejana de África. Tiene algún sitio habilitado para observadores amateur, pero es una isla con un aeropuerto pequeño y pocos hoteles. Es muy complicado ir allí con un telescopio grande y hay mucha demanda de turismo (no es un sitio barato).

 

Canarias puede ser un destino interesante para gente del Norte de Europa, pero en la península hay varias zonas con cielos muy oscuros, buen clima y que son fácilmente accesibles en coche. Ir a Canarias no es una mejora espectacular. Normalmente, aquí la gente se va a Argentina o a Chile cuando quieren explorar el hemisferio Sur en cielos realmente oscuros.

 

 

 

I've been to the island of Lanzarote (the closest to Africa) but there was light pollution, there's a lot of tourism and the islands are rather small.

 

The only island that has really dark skies is La Palma, the farthest island from Africa. It has some places for amateur observers, but it is an island with a small airport and few accomodations. It is very complicated to go there with a large telescope and there is a lot of demand for tourism (not a cheap place).

 

The Canary Islands can be a good astronomical destination for people from Northern Europe, but in mainland Spain there are several areas with very dark skies and good weather that are easily accessible by car. Going to the Canary Islands is not a spectacular improvement. Usually, spanish people go to Argentina or Chile when they want to explore the Southern Hemisphere in really dark skies.

 

 

 

Regards.

[Redbetter]

From 32.4 N Omega Centauri was an impressive naked eye object in ~Bortle 4 skies.  I didn't have any trouble recognizing it in the star pattern well above the not particularly old or tall pine trees south of my site since they were at least 100 to 200 or more yards distant depending on position (a gun range with backstop and clearing beyond.)  It suffers a lot as one proceeds N.  By 37 N I find myself sitting in the dirt, trying to find a space between tall trees to the south so that I can spot in in binoculars or a finder.  With bright light domes to the S, otherwise dark sites show Omega Centauri as a shadow of its former glory.  It is still big, and I resolve many stars, but the difference in relative appearance is huge.  Observing an object at ~5 degrees creates a lot of problems with respect to extinction, seeing, and atmospheric chromatic dispersion.   Each piles onto the other.  

[Carolina Observer]

I live in the foothills of North Carolina at a latitude of 35º 18' and can see both Omega Centauri and Centaurus A, observing from the rim of the South Mountains.  

 

My sketches are included in the following link, as well as information notes, images from many others from various locations in the country. 

 

https://rogerivester...north-latitude/

Edited by Carolina Observer, 16 April 2024 - 08:39 AM.

[Jon Isaacs]

My most amazing views of Omega Centauri have been when camping with craggy mountains to the south.  The first time I experienced this was observing from the Kelso Dunes in the Mojave National Preserve with the Granite mountains to the south.  The Preserve is at 34.9 degrees North latitude and with the mountains to the south, I was not sure if it would be visible but I did keep an eye open just in case.  The skies are very dark to the south. 

 

Suddenly, I saw Omega Centauri begin to emerge horizontally from one of the crags in the mountains and transverse the crag and then disappear only to reappear in another crag.. It was very bright and sparkly and was never more than a degree above the mountain.  The horizontal "rising" meant that it was emerging into dark sky, it was a very special aesthetic event.. Naked eye, binoculars, refractor, Dob, it was a stunning view.  

 

The next night, my wife got up out of her warm bed to witness it despite the fact that was 3 am and 30 degrees.. '

 

I have also seen this camping in the Saddle Mountain Dispersed camping area,  One must be in the right spot.. You can see the jagged mountains to the south.

 

 

Jon

[12BH7]

In my better days I would camp on Mt Ord to observe. Unfortunately the position always put it in the Phoenix light dome.

[Jon Isaacs]

In my better days I would camp on Mt Ord to observe. Unfortunately the position always put it in the Phoenix light dome.

 

At Saddle Mountain, there's a massive light dome to east from Phoenix but to the south, west and north, the skies were quite dark.

 

It wasn't an ideal stargazing site but the primary purpose of our trips was to visit with the middle son during Covid. He's an electrical engineer and lives in Wisconsin but was in the Phoenix area doing software installs in the construction of a large factory.

 

Jon

[Darren]

Wow, nice work bagging both those objects from a northern latitude. Well done! Dark skies and good seeing are crucial.

I brought my 15x70 bino's on vacation to Cuba a few years back and got Omega Centauri easily. It was a bright, round snowball, but no stars were resolved.

I also tried to locate Centaurus A but with no luck. Would love yo take a trip far south to do some observing.

[Ken....]

I'm heading to Barbados for vacation, so Omega Centauri should be easy, right? I taking just 10x50 binoculars with me.

[Domdron]

I love Omega Centauri, it’s an easy naked eye object from my Bortle 4-5 backyard at my 1°16“ South home. In a recent night, it was particularly impressive because a power cut in the wider area transformed my sky into about better Bortle 4.

But then I haven’t seen it in over a week now because of the „long rains“ season here right now. And the other night, my observation session was cut short by a Safari Ant invasion in our garden…

[Jon Isaacs]

Wow, nice work bagging both those objects from a northern latitude. Well done! Dark skies and good seeing are crucial.

I brought my 15x70 bino's on vacation to Cuba a few years back and got Omega Centauri easily. It was a bright, round snowball, but no stars were resolved.

I also tried to locate Centaurus A but with no luck. Would love yo take a trip far south to do some observing.

 

I am able to Centaurus A in a 50mm finder from 32.7 degrees north.  It's just a faint glow..  in a Dob, the dust lane is easily seen but no much else.  

 

Jon

[Special Ed]

Looking at Omega Centauri is a challenge I take just about every spring.  At my latitude, as Fernado said in his original post, it takes waiting for the right combination of weather, topography, and timing.  My place is at an elevation of 2750 feet/838 meters on the side of a mountain facing south so I have an advantage there.  Even so, OC only reaches a maximum altitude of 4.5° at culmination.  [I had thought that Centaurus A would be easier to spot since it is about twice as high, but it has only appeared as a dim glow so far--when it appears at all]

 

I sketched my first couple of attempts--one with a C8 and one with my 15x70 binoculars, but I could not resolve any stars, or even see much beyond the core.  Just seeing it at all is the reward.  

 

Once I got a little better at astrophotography I got the bright idea that I would try for an image.  First try was a fail--but we learn from our failures, right?  Second try came out better.  [Edit: Forgot to mention image details.  Canon T5i, 250mm, f5.6, ISO 1600, 59x15sec, Omegon LX-2 wind up tracker]

 

The sketches and image were all made from my house.

 

 

 

Edited by Special Ed, 22 April 2024 - 09:12 AM.

[Larry Mc]

I got my best observation of Omega last April at Calhoun Cty Park (38 deg) in WV. setup in the new astronomy field.

Here's an excerpt of my notes from Tuesday, April 18th, 2023:

 

"With the clock now past midnight, the ‘witching hour’ of Centaurus collimating on the meridian was fast approaching. It was time to prepare for the highlight of my entire trip, EAA observing the great globular cluster Omega Centauri!

After first settling on a nearby bright 2nd mag star “Menkent” (theta Centauri) to check the camera focus with the bhatinov mask, I then slewed the telescope further south, to the peculiar galaxy NGC5128, also known as ‘Centaurus A’. While I have observed this interesting galaxy several times over the last half-dozen years from the ridge at Calhoun, as part of my Arp Peculiar Galaxy project work, this galaxy was in my ‘top three’ list of objects for this camping trip.
I was looking forward to getting a clear EAA view of the galaxy from the new observing field’s low southern horizon, and I was not disappointed. At around 7.5 degrees elevation, the giant elliptical galaxy NGC5128 with its bisecting dusk-lane was a fine looking object! I would have liked to have stayed awhile longer on this peculiar galaxy, but the deep-sky object that was the whole reason for being at Calhoun in April was also nearing peak altitude on the southern meridian. I had to move on.

 

So I then slewed the telescope nearly horizontal, to the lower position of Omega Centauri, NGC5139, which was approaching the meridian and its maximum elevation of about 3.44 degrees.

After a 15 second subframe exposure, the globular cluster filled the center of the monitor display, with streamers of stars extending towards the edges of the field. Quite a sight!

According to info in the ‘Annals of the Deep Sky”, at a distance of 17,000 light-years and with a diameter of around 270 light-years, a number of Omega’s astrophysical characteristics points to the possibility that the ‘cluster’ is actually the remnant nucleus of a dwarf galaxy that was consumed by the much larger Milky-Way, similar to several other ‘globulars’ such as M54.

Here’s the observation:

 

(8" SCT @ f6.3 on an Atlas Gem, ZWO ASI294MC camera with L-Pro filter, 15 second subs, dark & flat calibration frames, PHD guided, livestacked using Sharpcap for 75 seconds).

 

I was able to immediately see the dark feature that I noted last fall, called the "Eye of Omega", which is possibly a dark molecular cloud that is in front of the cluster in our line-of-sight. This is generally only seen visually, as most images are longer exposures to pull-out more of the fainter cluster stars. (to me the feature resembles a skull,,,,)   ........

   

With this observation, I had finally got a good observation of the greatest globular cluster in the sky, a bucket-list astronomical goal that I had been carrying with me since the mid-80’s when I had a brief glimpse of omega thru a 10” dob. Life is good!!"

 

(I actually went back two nights later on the 20th and was able to achive a better guided observation of Omega).

 

[Dave Mitsky]

I've had some fantastic views of NGC 5139 (Omega Centauri) from the Florida Keys at the Winter Star Party and western Texas at the Texas Star Party and even more so (and of NGC 104, also known as 47 Tucanae) from the shores of Lake Titicaca in Bolivia. 
 

One of the high points of nighttime observing during the Texas Star Party's TSP 2024 Total Solar Eclipse and Star Party was seeing Omega Centauri again through an EAA rig employing a 10" Dob, an 85mm Tele Vue refractor, and my 101mm Tele Vue refractor.

[maroubra_boy]

Yeah, come south of the equator to really get the most of these two.  It will also help with seeing "The Eye of Omega", a line of sight coincidence of a small molecular cloud sitting between us and Omega.  Easily noticed with an 8" scope under a light polluted sky.  The Eye is often missed, but once you see it you can no longer un-see it.

 

Both sketches done using a 17.5" dob, Omega from my home in Sydney (Bortle 8) and Centaurus A from a dark site on a night of a little reduced transparency.  Both were sketched directly on to black paper at the eyepiece.

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Edited by maroubra_boy, 22 April 2024 - 06:12 PM.