25 Feb 2012 - Observation Report at Sedili Besar with 15” f/4.5 dob
Last Saturday 25 Feb 2012, my wife and I went for another overnight observation trip to Tanjung Sutera Resort at Sedili Besar, Malaysia, together with the three other veteran observers: Jiahao, Yang Beng and Elton. Kochu also drove over to do some imaging. There were also five cars from TASOS; those guys were also doing astro-imaging in the same area.
That night, the sky condition was 50-70% cloud cover from 8pm to 4am. Sky transparency was variable at mostly 6/10, occasionally peak at 8/10 when we saw the Horsehead. Seeing was mostly variable at 7-8/10, peaked at 10/10 when we observed Mars & Saturn. NELM at zenith was about magnitude 6.0. High altitude thin hazy cloud was prevalent, and there was occasional slight wind but not as chilly as the week before. Surprisingly there was no dew at all. Mosquitoes were minimal at the observation site; I was bitten only once after midnight.
We observed with my 15” f/4.5 dob from 7.30pm to 4.30am, and each of us observed probably at least 50 objects or more. Paracorr II was in use all the time, bringing the scope focal ratio to f/5.175 and focal length to 1971.675mm.
The following eyepieces (and magnification) were used:
40mm XW (50x) 1.4 deg TFOV
30mm XW (66x)
17mm Ethos (116x)
8mm Ethos (246x)
6mm Delos (328x)
5mm XW (394x)
3.5mm XW (563x)
3mm [6mm Delos + Zeiss barlow 2x] (657x)
2.5mm [5mm XW + Zeiss barlow2x] (788x)
Here are some key highlights of certain objects I recorded for this observation:
1. Jupiter: Io in transit was visible at 116x with the 17mm Ethos. It was quite amazing at this low power, but the image contrast was good so Io was just visible. The satellite became more distinct at 246x with the 8mm Ethos. We also took a quick look at Venus in gibbous phase, it was too bright. In contrast, the thin crescent Moon was not too bright, and the whole Moon was nicely framed with the 17mm Ethos.
2. The California Nebula (NGC 1499) in Perseus, was positively observed with the H-Beta filter with the 40mm XW eyepiece at 50x. This is a huge nebula that spans across at least three FOV of this eyepiece. Compared with the first time I saw it vaguely in a 10” scope many years ago, this time it is much brighter and with higher contrast, so the edge of the nebula is more clearly defined.
3. The Horsehead Nebula (B33 with IC 434) in Orion was seen clearly that night, with better contrast than the same observation two weeks earlier. We used the H-Beta filter with the 40mm XW eyepiece at 50x. Again we were quite lucky similar to two weeks prior, where the sky transparency was generally not that good at 6/10 but Orion was at zenith and culminated within a clearer patch of sky, so transparency there was about 8/10.
4. The Monkey Head Nebula (NGC 2174) in Orion, is a rather large faint nebula nicely framed in the 40mm XW eyepiece at 50x. The Oxygen-III filter was used to bring out the contrast, otherwise without any filter, it was barely visible.
5. The Medusa Nebula (PK 205+14.1 or Abell 21) in Gemini, is a large but very dim planetary nebula that was just barely visible with the 40mm XW eyepiece at 50x with the O-III filter. Transparency was not that good at this point in time.
To be continued ...
horsehead seen last night...Sedili ob report
Re: horsehead seen last night...Sedili ob report
Richard Low
Re: horsehead seen last night...Sedili ob report
6. The Orion Nebula (M42) and neigbouring nebula M43 was nice that night but not so spectacular as seen two weeks earlier as the fine filamentary structure are not clearly visible at 116x. Strangely, the transparency here suffers somewhat even though we had better transparency at the nearby Horsehead Nebula which we observed just a while earlier.
7. The Eskimo Nebula (NGC 2392 ) in Gemini is a splendid planetary nebula at 563x, with the furry hood visible around the ‘face’ disc which also shows some details besides the central star.
8. The Rosette Nebula (NGC 2237-2239, 2246), and open cluster (NGC 2244) within, is a really nice huge ‘flower’ in Monoceros . It appeared slightly bigger than the 1.4 degree TFOV in the 40mm XW with the O-III filter. Some sources list the apparent size as 60 arcmin or 1 degree which is not correct. It is closer to 90 arcmin. A quadrant of the rose is noticeably darker than the rest. The associated star cluster within is actually quite pretty but it is sadly eclipsed in grandeur by the nebula itself. I think the transparency affected the image quality here too, otherwise the nebula should appear brighter, bigger and more defined.
9. The Christmas Tree Cluster & Cone Nebula (NGC 2264) in Monoceros was viewed at 50x with the O-III filter. The Cluster is an easily visible object but the Cone Nebula was not positively identified. Have to try again when the sky transparency is better.
10. Thor’s Helmet Nebula (NGC2359)in Canis Major is a relatively large object that is nicely framed in the 17mm Ethos at 116x with the O-III filter. The “wings” on the ‘Helmet’ makes this a very uniquely-shaped planetary nebula indeed.
11. Caldwell 90 (NGC 2867 or PK 278-5.1)in Carina is easily found just besides the “False Cross”. Very small planetary nebula, only 11 arc-seconds in diameter.
12. Eight-Burst Nebula, (NGC 3132) in Carina, is a relatively large planetary nebula observed at 246x and 394x.
13. Ghost of Jupiter Nebula (NGC 3242) in Hydra was again observed as a spectacular planetary nebula with great detail at 246x and 394x without any filter. At such high power, it doesn’t look like a ghostly-image of Jupiter anymore. Instead, the oval inner-ring and central star surrounded by the outer halo reminds me of an eye…the Eye of Sauron…LOL! Edit:I found out it is also called the Eye Nebula.
14. Mars was splendid at 563x, 657x and 788x magnification. The image was still sharp at 788x and there was a huge amount of details in various hues of colors that was seen at such high power. It was getting a little bit tricky to hand-track at 657x and 788x but we did managed it. It was relatively easy to hand-track at 563x on this dob. Incidentally this is beyond the 50x per inch (ie, 750x) milestone for the 15” dob, and this only attest to the superb quality of the Zambuto mirror. Carl Zambuto issues a guarantee for every ZOC mirror that he made, stating that it can perform to 50x per inch or better (subject to certain conditions in the optical train), and on that night, this was indeed proven.
15. Saturn was awesome at 788x and 657x! The image was still sharp at this ridiculously high power and at three occasion, I observed the Encke Division for brief moments at the ansae. At other times, only the Encke Minima was constantly visible but at these precious moments when the seeing turns motionless and perfect, the Encke Division just appeared for a second or two. Very precious experience indeed! The first and only other time I saw the Encke Division was in 2005 so I had been searching for this moment for a long time. Incidentally many observers think that Saturn’s rings are still not open enough for observing the Encke Division, and the appropriate time to catch this elusive object is another two years down the road, so we must be really lucky that night.
To be continued...
7. The Eskimo Nebula (NGC 2392 ) in Gemini is a splendid planetary nebula at 563x, with the furry hood visible around the ‘face’ disc which also shows some details besides the central star.
8. The Rosette Nebula (NGC 2237-2239, 2246), and open cluster (NGC 2244) within, is a really nice huge ‘flower’ in Monoceros . It appeared slightly bigger than the 1.4 degree TFOV in the 40mm XW with the O-III filter. Some sources list the apparent size as 60 arcmin or 1 degree which is not correct. It is closer to 90 arcmin. A quadrant of the rose is noticeably darker than the rest. The associated star cluster within is actually quite pretty but it is sadly eclipsed in grandeur by the nebula itself. I think the transparency affected the image quality here too, otherwise the nebula should appear brighter, bigger and more defined.
9. The Christmas Tree Cluster & Cone Nebula (NGC 2264) in Monoceros was viewed at 50x with the O-III filter. The Cluster is an easily visible object but the Cone Nebula was not positively identified. Have to try again when the sky transparency is better.
10. Thor’s Helmet Nebula (NGC2359)in Canis Major is a relatively large object that is nicely framed in the 17mm Ethos at 116x with the O-III filter. The “wings” on the ‘Helmet’ makes this a very uniquely-shaped planetary nebula indeed.
11. Caldwell 90 (NGC 2867 or PK 278-5.1)in Carina is easily found just besides the “False Cross”. Very small planetary nebula, only 11 arc-seconds in diameter.
12. Eight-Burst Nebula, (NGC 3132) in Carina, is a relatively large planetary nebula observed at 246x and 394x.
13. Ghost of Jupiter Nebula (NGC 3242) in Hydra was again observed as a spectacular planetary nebula with great detail at 246x and 394x without any filter. At such high power, it doesn’t look like a ghostly-image of Jupiter anymore. Instead, the oval inner-ring and central star surrounded by the outer halo reminds me of an eye…the Eye of Sauron…LOL! Edit:I found out it is also called the Eye Nebula.
14. Mars was splendid at 563x, 657x and 788x magnification. The image was still sharp at 788x and there was a huge amount of details in various hues of colors that was seen at such high power. It was getting a little bit tricky to hand-track at 657x and 788x but we did managed it. It was relatively easy to hand-track at 563x on this dob. Incidentally this is beyond the 50x per inch (ie, 750x) milestone for the 15” dob, and this only attest to the superb quality of the Zambuto mirror. Carl Zambuto issues a guarantee for every ZOC mirror that he made, stating that it can perform to 50x per inch or better (subject to certain conditions in the optical train), and on that night, this was indeed proven.
15. Saturn was awesome at 788x and 657x! The image was still sharp at this ridiculously high power and at three occasion, I observed the Encke Division for brief moments at the ansae. At other times, only the Encke Minima was constantly visible but at these precious moments when the seeing turns motionless and perfect, the Encke Division just appeared for a second or two. Very precious experience indeed! The first and only other time I saw the Encke Division was in 2005 so I had been searching for this moment for a long time. Incidentally many observers think that Saturn’s rings are still not open enough for observing the Encke Division, and the appropriate time to catch this elusive object is another two years down the road, so we must be really lucky that night.
To be continued...
Last edited by rlow on Sun Mar 04, 2012 9:33 am, edited 1 time in total.
Richard Low
Re: horsehead seen last night...Sedili ob report
16. Eta Carinae Nebula and Homunculus Nebula in Carina wasn’t too spectacular that night as the transparency in that area wasn’t that good. The Homunculus Nebula appeared as a bi-lobed flame-shaped nebula immediately surrounding the star Eta Carinae at high power. One of the flame is bigger than the other on the opposite side of the star. We observed at 246x and 394x and the flame was pale yellowish; I had previously seen it appeared bright pink in a 11”f/5 dob on a good night.
17. Omega Centauri (NGC 5139) in Centaurus was not too spectacular at first sight at 246x in which the cluster core fills up the whole FOV of the Ethos 8mm quite nicely, but a later viewing at 116x with the Ethos 17mm showed it in its full splendour, scintillating pin-point stars sprinkled all over the core giving that 3-dimensional effect. Not to be missed!
18. Centaurus A Galaxy (NGC 5128) in Centaurus is a large elliptical galaxy which we affectionately call the ‘Hamburger’ Galaxy. It has two sesame buns (galactic halo) covering two beef patties (dust lanes) separated by a layer of cheese (or onion) which is a thin sliver of light right down the middle. That night the transparency was not good in that area, so this object give a poor showing.
19. The Southern Pinwheel Galaxy (M83)in Hydra nearby was much better, and the spiral arms could be seen clearly. A nice big and bright spiral galaxy that showed the spiral arms at 246x.
20. The Sombero Galaxy (M104)in Virgo is a large bright galaxy that is uniquely-shaped and striking. Very lovely galaxy with the dust lane seen at 116x and 246x.
21. The Leo Triplet Galaxies (M65, M66 & NGC 3628) in Leo are a lovely set of triple galaxies seen together at 116x in the Ethos 17mm. Individual galaxy begin to show more details like dust lanes and fill up the FOV at 246x in the Ethos 8mm.
22. Another Leo Trio Galaxies (M105, NGC 3384, NGC 3389) in Leo are another lovely trio galaxies visible together in the same FOV. We also took a look at the nearby galaxies M96 & M95. We observed that M96 was an oval-shaped galaxy with hints of its spiral arms, while M95 was more roundish, the bars were evident and there was hint of the dark lane separating the coma from the outer arms.
23. The Markarian’s Chain Galaxies comprising of Smiley Face Galaxies (M84, M86, NGC 4387, 4388, 4402, 4413, 4425), plus The Eyes Galaxies (NGC 4435 & 4438) and the rest (NGC 4458 & 4461 pair), (NGC 4473), (NGC 4477 & 4479 pair) forms a striking curved chain of galaxies in the Virgo Cluster. In one FOV at 50x with the XW 40mm, I could see nine galaxies at one glance, centered around the Smiley Face Galaxies. A few years ago using Elton’s 10” f/5 Teleport, we were able to see 13 galaxies (the whole Markarian Chain) in one FOV using the XL 40mm at 31.75x.
24. The Whale Galaxy (NGC 4631) & Pup (NGC 4627) in Canes Venatici are quite lovely. For NGC 4631, the fore-fin and eyes of the ‘whale’ was visible. The Pup is a small faint smudge adjacent to the ‘whale’.
25. The Crowbar Galaxy (NGC 4656 & 4657) in Canes Venatici. The Crowbar Galaxy is also known as the Hockey Stick Galaxy, and NGC 4657 is the hook at the end of the galaxy NGC 4656. The Crowbar Galaxy and Whale Galaxy should fit into the 1.4 degree FOV of the XW 40mm at 50x.
26. The Needle Galaxy (NGC 4565) in Coma Berenices is a big beautiful edge-on galaxy that shows the prominent dust lane at 116x. The galaxy fills the whole FOV and showed more details at 246x.
27. The Black Eye Galaxy (M64) in Coma Berenices was also observed that night. The prominent dark dust lane that form around the nucleus was easily visible at 116x.
28. Bode’s Galaxy (M81) & Cigar Galaxy (M82) in Ursa Major was a splendid sight seen together at 116x that night despite the lower elevation viewed just over the tree-tops. I could see the spiral arms in M81 and the dust lane bisecting M82.
29. The Whirlpool Galaxy (M51) & adjoining galaxy (NGC 5195) in Ursa Major was a spectacular showpiece that night. The areas between the spiral arms were dark and so I could traced out three spiral arms with direct vision, one of them joining all the way to the other galaxy NGC 5195.
30. The Pinwheel Galaxy (M101) in Ursa Major was surprisingly very bright in the Ethos 17mm at 116x. The dark lanes between the spiral arms were in good contrast, so I had no difficulty tracing out four spiral arms around the central nucleus. The visibility of the spiral arms was as easy as M51. Some brighter patches of H-II regions could be seen and this merits further observation in future on a clearer night.
31. The Owl Nebula (M97) in Ursa Major was observed with the two eyes and the central star visible at 394x.
32. Comet Garradd is big and bright as seen through Yang Beng’s Fujinon 10x50mm binocular. I also somehow did managed to glimpsed it as a very faint naked-eye object with averted vision.
There were some other deep-sky objects we had observed but I had missed in this report or probably forgotten
Can anyone remember the name of that planetary nebula we saw with the four stars inside at the centre?
17. Omega Centauri (NGC 5139) in Centaurus was not too spectacular at first sight at 246x in which the cluster core fills up the whole FOV of the Ethos 8mm quite nicely, but a later viewing at 116x with the Ethos 17mm showed it in its full splendour, scintillating pin-point stars sprinkled all over the core giving that 3-dimensional effect. Not to be missed!
18. Centaurus A Galaxy (NGC 5128) in Centaurus is a large elliptical galaxy which we affectionately call the ‘Hamburger’ Galaxy. It has two sesame buns (galactic halo) covering two beef patties (dust lanes) separated by a layer of cheese (or onion) which is a thin sliver of light right down the middle. That night the transparency was not good in that area, so this object give a poor showing.
19. The Southern Pinwheel Galaxy (M83)in Hydra nearby was much better, and the spiral arms could be seen clearly. A nice big and bright spiral galaxy that showed the spiral arms at 246x.
20. The Sombero Galaxy (M104)in Virgo is a large bright galaxy that is uniquely-shaped and striking. Very lovely galaxy with the dust lane seen at 116x and 246x.
21. The Leo Triplet Galaxies (M65, M66 & NGC 3628) in Leo are a lovely set of triple galaxies seen together at 116x in the Ethos 17mm. Individual galaxy begin to show more details like dust lanes and fill up the FOV at 246x in the Ethos 8mm.
22. Another Leo Trio Galaxies (M105, NGC 3384, NGC 3389) in Leo are another lovely trio galaxies visible together in the same FOV. We also took a look at the nearby galaxies M96 & M95. We observed that M96 was an oval-shaped galaxy with hints of its spiral arms, while M95 was more roundish, the bars were evident and there was hint of the dark lane separating the coma from the outer arms.
23. The Markarian’s Chain Galaxies comprising of Smiley Face Galaxies (M84, M86, NGC 4387, 4388, 4402, 4413, 4425), plus The Eyes Galaxies (NGC 4435 & 4438) and the rest (NGC 4458 & 4461 pair), (NGC 4473), (NGC 4477 & 4479 pair) forms a striking curved chain of galaxies in the Virgo Cluster. In one FOV at 50x with the XW 40mm, I could see nine galaxies at one glance, centered around the Smiley Face Galaxies. A few years ago using Elton’s 10” f/5 Teleport, we were able to see 13 galaxies (the whole Markarian Chain) in one FOV using the XL 40mm at 31.75x.
24. The Whale Galaxy (NGC 4631) & Pup (NGC 4627) in Canes Venatici are quite lovely. For NGC 4631, the fore-fin and eyes of the ‘whale’ was visible. The Pup is a small faint smudge adjacent to the ‘whale’.
25. The Crowbar Galaxy (NGC 4656 & 4657) in Canes Venatici. The Crowbar Galaxy is also known as the Hockey Stick Galaxy, and NGC 4657 is the hook at the end of the galaxy NGC 4656. The Crowbar Galaxy and Whale Galaxy should fit into the 1.4 degree FOV of the XW 40mm at 50x.
26. The Needle Galaxy (NGC 4565) in Coma Berenices is a big beautiful edge-on galaxy that shows the prominent dust lane at 116x. The galaxy fills the whole FOV and showed more details at 246x.
27. The Black Eye Galaxy (M64) in Coma Berenices was also observed that night. The prominent dark dust lane that form around the nucleus was easily visible at 116x.
28. Bode’s Galaxy (M81) & Cigar Galaxy (M82) in Ursa Major was a splendid sight seen together at 116x that night despite the lower elevation viewed just over the tree-tops. I could see the spiral arms in M81 and the dust lane bisecting M82.
29. The Whirlpool Galaxy (M51) & adjoining galaxy (NGC 5195) in Ursa Major was a spectacular showpiece that night. The areas between the spiral arms were dark and so I could traced out three spiral arms with direct vision, one of them joining all the way to the other galaxy NGC 5195.
30. The Pinwheel Galaxy (M101) in Ursa Major was surprisingly very bright in the Ethos 17mm at 116x. The dark lanes between the spiral arms were in good contrast, so I had no difficulty tracing out four spiral arms around the central nucleus. The visibility of the spiral arms was as easy as M51. Some brighter patches of H-II regions could be seen and this merits further observation in future on a clearer night.
31. The Owl Nebula (M97) in Ursa Major was observed with the two eyes and the central star visible at 394x.
32. Comet Garradd is big and bright as seen through Yang Beng’s Fujinon 10x50mm binocular. I also somehow did managed to glimpsed it as a very faint naked-eye object with averted vision.
There were some other deep-sky objects we had observed but I had missed in this report or probably forgotten
Can anyone remember the name of that planetary nebula we saw with the four stars inside at the centre?
Last edited by rlow on Fri Mar 02, 2012 10:53 pm, edited 1 time in total.
Richard Low
Re: horsehead seen last night...Sedili ob report
Amazing report. Thanks! You have elephant memory!
http://www.astro.sg
email: gary[at]astro.sg
twitter: @astrosg
"The importance of a telescope is not how big it is, how well made it is.
It is how many people, less fortunate than you, got to look through it."
-- John Dobson.
email: gary[at]astro.sg
twitter: @astrosg
"The importance of a telescope is not how big it is, how well made it is.
It is how many people, less fortunate than you, got to look through it."
-- John Dobson.
Re: horsehead seen last night...Sedili ob report
Very detailed report ![[smilie=admire.gif]](./images/smilies/admire.gif "admire")
Made me so envy with all these nebs...
But frankly, even in SG, there have been many clear nights lately. Been happy even just see the crescent moon, jup and orion with unaided eye
Made me so envy with all these nebs...But frankly, even in SG, there have been many clear nights lately. Been happy even just see the crescent moon, jup and orion with unaided eye
Re: horsehead seen last night...Sedili ob report
Thanks Gary & stargazer.
On the contrary, we need to jot down our memory, that's also why we write it down here...not just to share our experiences with you guys, but also to recall later otherwise we may have forgotten what we had seen by the next new-moon observation
On the contrary, we need to jot down our memory, that's also why we write it down here...not just to share our experiences with you guys, but also to recall later otherwise we may have forgotten what we had seen by the next new-moon observation
Richard Low
-
Canopus Lim
- Posts: 1144
- Joined: Fri Jun 03, 2005 12:46 pm
- Location: Macpherson
Re: horsehead seen last night...Sedili ob report
VinSnr,
Wow Sumerian telescope..they look like works of art in the pictures!
Wow Sumerian telescope..they look like works of art in the pictures!
AstroDuck
Re: horsehead seen last night...Sedili ob report
Yes Vincent, the Sumerian Optics scopes does look good indeed!
which model and size did you get?
how about showing it to us this weekend...?
which model and size did you get?
how about showing it to us this weekend...?
Richard Low
Re: horsehead seen last night...Sedili ob report
Yeap, the parts are cut to very precise tolerances until everything could be fitted into the box.Canopus Lim wrote:VinSnr,
Wow Sumerian telescope..they look like works of art in the pictures!
It's quite amazing how the maker did that to keep the compactness.
Re: horsehead seen last night...Sedili ob report
14.5", f/4.5 with a Waite Research mirror.rlow wrote:Yes Vincent, the Sumerian Optics scopes does look good indeed!
which model and size did you get?
how about showing it to us this weekend...?
Took 9 months, a very demanding project in terms of logistic because of the need to make the mirror in US before flying the mirror to Holland for final assembly onto the scope.
BTW, arrived 3-4 weeks ago and I have not even set it up yet! There is still a need to make a shroud.
Anyway, great report on the observations and great memory too! Amazing the amount of stuff you guys see without GOTO. Still human GOTO is the best.