Object of the Week, January 2, 2022 - NGC 1514, the Crystal Ball Nebula

[Uwe Glahn]

Constellation: Taurus
R.A.: 04h 09m 17s
Dec.: +30° 46' 35"
Size nebula: 2.2'
Size halo: 3'
Magnitude nebula: 10.9v
Magnitude CS: 9.4

Our present OOTW starts as often with a funny and exiting history. William Herschel discovered this object in November, 1790 as a "star with atmosphere". With this discovery he changed his theory about planetary nebula. He was thinking partly right, that the nebula mass were not unresolved stars but "luminous fluid" around the dominant central star which is a product of the nebula mass itself. Remember, Herschel uses a 18.7-inch speculum mirror, which is comparable with a modern 10-inch to 12-inch reflector. With bigger mirrors, details began to be resolved. Also at NGC 1514. Lord Rosse and his co-observer saw the first details in the halo and interpret, sketch and classify them as spiral structure ("new spiral of an annular form round the star, which is central; spirality is very faint"). The used "Leviathan" telescope has a 15-times larger light gathering power and uses a 72-inch speculum mirror, comparable with a modern 36-inch reflector.

But what is NGC 1514 or better, why does it looks like a Crystal Ball. What do we see - an inner shell, some bubble structures and an outer shell, often called halo here around a single bright central star. Today we know, that the central star - a binary system causes the morphology of nearly all non-spherical PNe. The 9.4mag bright BD +30°623 central star consist of a cool main component and a hot companion with a record breaking period of over 9 years [2017A&A...600L...9J]. The observed structure is only a two dimensional projection of a complicated structure. By using high resolution long-slit spectra, the latest scientific studies shows a 3D model of the PN [link to the preprint arXiv:2105.01495]. This model presents an inner distorted shell with some additional and well-defined bubbles and an outer spherical attached shell. The pictured model is very clearly and I recommend to view this at side 7.

From the observing side, NGC 1514 is one of the only PNe who shows his central star even in binoculars. To resolve the single bubbles needs some patience, but is possible to see even in smaller apertures. My former 16-inch shows clear sights of these structures. Because of its strong [OIII] emissions, a filter might help to resolve the morphology. To show all its natural beauty I often go without any filter. The shell structure is also visible. More important is the use of the right magnification and EP - high enough to resolve the structure and small enough to pass enough light. 1.5-2.0mm should work fine.

DSS blue, 10'x10'
DSS_10b.jpg

sketch: 16", 260x, [OIII], NELM 6m5+
NGC1514.jpg
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sketch: 27", 366x, no filter, seeing III, NELM 7m0+
NGC1514_27.jpg
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So, unless your aperture, share your present observation-reports or sketches. If you don't have any, as always, GIVE IT A GO AND LET US KNOW.

[obrazell]

Probably worth noting we have already covered this one https://www.deepskyforum.com/showthr...nary-planetary

[Raul Leon]

Hi, here's my observation from 1/18/2018: ngc 1514 planetary nebula in Taurus; aka the Crystal ball ; magnitude:10.9 ; size: 2' ; large : fairly bright, UHC filter works well to view light and dark patches throughout object, 9th mag central star easily seen, I used a 8mm Ethos at 233x with my 14.5 Starstructure f/4.3ngc 1514.jpg

[Uwe Glahn]

Ahhh, my research just missed the double post. I thought for a moment why this PN was no OOTW yet, but missed Steve's thread.

Thanks Raul, like always a very nice and realistic sketch.

[Robin]

Happy new year 2022!

NGC 1514 was one of the first objects I observed with 20". Please find attached my sketch. I noted that I saw a donut-shaped shell around this PN that has a brighter region with some bulges on one side.

Uwe, thanks for the paper! Seems to be very interesting to read. I will definitely read it when I'll have some more time.

Clear skies,

Robin

[Clear Skies]

This is by all means an object to return to frequently, definitely a showpiece.

My latest observation was 3 months ago in the French Alps, 14" SCT @ 168x / 29', filtered and unfiltered:

A large, almost round glow, slightly ovally shaped, subtly elongated NW to SE. The central star is very clearly visible, approximately mag. 9. To the NE and the SSW of the middle the nebula is slightly fainter. A beautiful nebula.

Lumicon UHC: This filter has a good effect. The nebula is clearly fainter SW of the middle, subtly fainter NE of the middle and brightest SE of the middle where a brighter part of the nebula is visible on the edge. The nebula is fainter on the SSW side in a triangular shape pointing NNE, towards the central star. With AV the nebula is more even in brightness and slightly flattened on the NE side on a line from SE to NW.

Lumicon OIII: The effect of this filter is comparable to that of the UHC filter but is subtly better. The dark part SSW of the middle and brighter part on the SE of the middle are clearer.

Two years ago, in the Ardennes, I upped the magnification a bit. Same scope but at 259x / 19', too:

17mm Nagler T4: Quite a large, faint glow with a very bright central star (SAO57020, approximately mag. 9). The nebula is subtly fainter to the SW of the central star.

17mm Nagler T4, Lumicon OIII: This filter has a better effect than the UHC filter, the nebula is brighter on the SE side and is brightest on the NW side. To the NE a dark part can be discerned, the nebula is clearly fainter SW of the central star.

17mm Nagler T4, Lumicon UHC: Using this filter the nebula is brightest to the NW of the central star in a NNE-SSW elongated part. Without AV the nebula is fainter on the SW and almost interrupted. Using AV the nebula is more even in brightness, subtly brighter on the SE side and brightest on the NW side.

11mm Nagler T6: The nebula is clearly brighter on the SE side and brightest on the NW side. Without AV almost no nebulosity is visible on the SW side. Using AV it is clear that the fainter part is to the SSW of the central star, an interruption in the nebula.

11mm Nagler T6, Lumicon OIII: This filter has a better effect than the UHC filter, using AV the nebula has irregular structure. To the NE of the middle a dark part can clearly be discerned, the nebula is "closed" in that part, contrary to the SSW side where the nebula is interrupted. Filters perform well on this object.

11mm Nagler T6, Lumicon UHC: Using this filter more nebulosity is visible and it clear the interruption of the nebula is to the SSW of the central star.

On both occasions I rated it 8/10.

ngc1514-1.jpg ngc1514-2.jpg

Click here to download the observing guide.

[Don Pensack]

My recollections of this nebula under exceptional conditions with the 12.5" are that this was just about the only nebula I've ever seen a purple tint in.
I recorded the color twice several years apart.