This region of the sky is an interesting, yet often neglected area by amateur observers. It contains two enigmatic planetaries - one of which has a most bizarre history. The area of the first contain various pretty pairs, a dark nebula and several marvellous asterisms. The second area is near an interesting globular and a number of pairs.

NGC 5844 (PK317-5.1/ SA2-115/ WRAY 16-168/ He2-119) (15107-6440) TrA is part of a small arc of stars in the western portion of Triangulum Australe. According to most of the modern computer software that uses the Hubble Guide Star Catalogue, there is on right on top of the planetary a bright 7.6 magnitude bluish star (GSC9029:2732) that is not there. (See Footnotes.)

NGC 5844 at position 15h10'42.0"-64^O41'00 is listed as nonexistent, while the planetary SA2-115 is positioned at 15h10'39.9" -64^O40'19". The difference is a mere 52.8"sec.arc.- so likely that the two objects are really the same. (I will assume it is!) The original description by Dryer in the NGC was PB,PL,R,VGVLBM - Pretty Bright, Pretty Large, Round, Very Gradual and Very Little Brighter in Middle. A rather odd designation for this object, as it does not match its telescopic appearance. It has also been deleted from the revised NGC catalogue and no reason is given for this deletion. However, this difference has meant that most Star Atlases and Catalogues - including Sky Atlas 2000.0 and Sky Catalogue 2000.0, Uranometria 2000.0 (map 452.) etc. have not listed this fairly bright and interesting planetary. Recently, a Bowen Mountain all were surprised at the brightness of this object, especially as it lies close to the rear-end of Triangulum Australe and Beta Centauri. Using the 0.45 metre telescope at Bowen on the 23rd August 1997; Mick McCullagh and Don Whiteman (for their first time peek) took sometime to find this object among the brilliantly starry field of Triangulum Australe. When it was found, it was obvious. (Even some local visitors looked at this object, but as first timers I suppose they didn't understand the implications of what they were seeing. However, I did give an explanation the general nature of planetaries and their evolutions.)

To find this object, it is best to use the star Triangulum Australis in the middle of the base of the 'southern triangle' and the star Circini. Draw an imaginary line between the two stars. Divide this line by quarters, and move towards TrA from Cir by a whole quarter. This centres directly on the planetary where two 8th magnitude stars appear within the same field.

The visual magnitude is stated as 12.1 while the photographic magnitude of the planetary is 13.2. In size, NGC 5844 subtends an angle of 53"sec.arc. AOST2 states that this object is "..70"x50"sec.arc.", that is partly incorrect as even the photographic image never exceeds 55"sec.arc.

As an ovoid shaped object it is just visible in a 15cm., best found using an O-III filter with medium power. In AOST2, David Frew states that it can be easily found by blinking across the field an O-III filter. This is true for a 10cm. or 15cm. telescope, but any larger aperture can immediately detect its nebulosity. Using an O-III filter, the brightness is fairly even across the entire disk. I could also see a slight indentation in the northern edge of the planetary. Using a 30cm., the appearance of this indent becomes more pronounced, revealing an uneven edge, and this turns into a "bay" in telescopes exceeding 40cm. A 40cm or larger should also start to see some structure in the planetary - perhaps more obvious using an O-III or using a Hydrogen-Beta filter. Observers at Bowen, including Les Sara, thought that the appearance seemed mottled - and even more so with the O-III. Some faint bipolar features were also noted, with some difficulty, by each of them.

The PNN central star is invisible in all amateur telescopes and with a stated magnitude of 16.6 - this is understandable. Little in the literature is written about this object until the beginning of the 1990's. Any observational data available remains scant. Distance has been recently determined (c.1996) at 2.900 kiloparsecs.

The corresponding lack of data is a reflection of the poor quality of information on the object's catalogued position, perhaps more so with the rejection in the RNGC. Again, the northerners have actually 'butchered' this most wonderful object. Yet, if it were in the northern skies - we never hear the end of it! I recommend that members of the ASNSW have a look at this object. If you do so, please write a letter to the Editor (or to me.) If we can get enough information, we could punish those northerners by telling them in no uncertain terms what they are missing!

The Surrounding Field of NGC 5844. (See Field Chart and the Footnote.)

B832 (1510.9-6439) is a pair 4.0'min.arc. east of NGC 5844. Both stars are magnitude 9.4 and 11.4, respectfully, appear as yellow and orange. Since the first measure in 1927, little has changed with these stars that are separated by some 4.8"sec.arc. at position angle 79^O. West of B832 (15085-6438) by 17.0'min.arc. W and 3.0' N of NGC 5844, is a second pair - B831. The magnitudes are 8.7 and 10.9 respectfully, separated by 2.6"sec.arc. towards PA 108^O. Little has also changed with this pair in the last seventy years since its discovery. I see both stars as yellowish-white.

Asterism. Located 13'min.arc. NEE (PA ~55^O), and centred on position RA 15h 12m 23s Dec. -64^O 32' 29" is a lovely asterism of eight stars and finding it is easy. This object has no common name, and is not listed as a multiple star. The two brightest and closest stars (GSC9029:374 and GSC9029:167) are magnitudes 7.4 and 7.8. All the other stars are between magnitudes 9.8 and 13.8 in an area of about 4.0'min.arc. It would take a 20cm. in dark skies to see them all, that is best viewed using medium magnifications. (c.200X.)

Asterism. Centred on 14h51.0' -66^O 12' is another brighter asterism that my friend's 14-years old daughter Alexandra Popovic coins 'The Golden Horseshoe.' It lies between Alpha ( ) Circini and Gamma ( ) Triangulum Australis, and some two-thirds the bisected distance in a straight line between these stars. To the naked eye the brightest star in the asterism is the 6.2 magnitude bluish Zeta ( ) Circini (SAO252951). The Golden Horseshoe has a diameter c.0.8^O and contains some 25 stars - three of 6th magnitude, six are 7th, eleven of 8th and five of 9th. It also contains a number of double stars.In the finder, this asterism is obvious, though the larger telescopes may have serious trouble in getting the object within the telescopic field. A small telescope, say 7.5cm. or 10cm. using low power will have no trouble placing it into one field.

Asterism. Another 'mini-asterism' lies in the northern part of the 'horseshoe', which I call the 'Golden Snake'. This is an 'S' shaped line of stars that extends NNE from the 7.6 magnitude star SAO252951 (GSC9019:467) by some 12'min.arc. in length towards Alpha Circini. Twisted like a snake, the line of twelve 11th and 12th magnitude stars end in a 'forked tongue'. A 7.5cm. should see these easily in dark skies, a 10cm. if you are in a sky-lit suburb.

Bottom star of the straight line of five stars in the SE of the field of the horseshoe is the Innes triple I 369 (14487-6635). Magnitudes of the wide AB pair are 5.90 and 9.0, separated by 30.0"sec.arc. at PA 80^O., so this dainty white pair is easily visible in a 7.5cm. Closer inspection reveals that the B star is again double. At magnitudes 9.0 and 11.0, the BC components are separated by 2.7"sec.arc. at PA 224.1^O. Using medium powers, a 10.5cm. telescope easily splits these stars. For some reason Burnham's does not have it placed in his list of doubles within Circinus. Worst there seems a difference in the reference material in regards the AB separation. Of the four sources, Sky Catalogue 2000.0 lists it as 60.0"sec.arc, while others list it as 46", 30" and 6.0"sec.arc., respectfully. All my data quoted above is taken from the Washington Double Star Catalogue; 1996 (WDS96). Visually, 30"sec.arc. is closer to the truth. Checking the observational data, Geoffrey Douglass of the US Navel Observatory confirmed this is correct. The spectral types of the AB system are B2.5Ve and B7/8V. All proper motions are also similar, suggesting that the three stars are really associated. However, little has changed in the positions since Innes observations in 1902.

HJ 4707 (145420-662437) is the John Herschel pair, located on the opposite end of the horseshoe. This nearly equal yellow and white pair, has quoted magnitudes of 7.5 and 7.9. Since the first observation in 1837 the separation had slowly decreased, until sometime is the early 1960's. Ie. 1.5"sec.arc to a minimum of 0.54"sec.arc. Since then the separation has began to increase and according to the calculated ephemerides of the 4th Catalogue of Visual Binaries, the current separation is 0.84"sec.arc. at PA 294^O. Then if this is correct, an aperture of 20cm. could just resolve the pair under good seeing conditions and medium-high magnification. Visually, I can just see it in a 30cm., suggesting a separation of ~0.65-0.7 sec.arc. and the position angle may also be out by +10^O or so. It is possible that the binary star ephemeris is incorrect. (Any comments???) To my eyes, the pair appears strongly yellow in colour. It is no doubt, from the forty-one measures made to date, it is likely a long period binary. In 1948, Woolley and Mason calculated the retrograde orbit has a period of two hundred and eighty-eight years. Another known problem is the observed magnitude difference ( m). Herschel's observations state a difference of 0.4 - and this figure is given in the IDS. The most recent observations suggest no difference at all - magnitude 7.00 and 7.00, respectfully. My own observation suggests that the difference is nearer Herschel's. Could this be a suspected variable?

Alpha Circini (14424-6458)( 166) is further afield, and is the bright 3.4 magnitude star that is a wide binary with a beautiful colour contrast. The primary appears distinctly yellow while the companion is reddish. Discovered by Dunlop in 1828 and first measured by John Herschel in 1837, little change has occurred in the last 160 years except for a decrease in position angle by some 18^O, showing a retrograde orbit. As of 1994, the current separation is 15.7"sec.arc. and the position angle is 246^O. Once in the Third Catalogue of Visual Binaries this system was quoted as having a thousand-year long orbit, only to be rejected in the latest Fourth Catalogue. If it is a true binary, the period must be a few millennia. Recently, the 'A' component was thought by double star observers to be a variable. (Ie. WDS96) As yet it is not listed in the NSV. The pair is easily visible in a 7.5cm. In larger apertures, it is absolutely beautiful in a star-studded field.

Between the 'Golden Horseshoe' and Circini is a dark nebula. Typically dark nebulae are boring. However, this one is interesting because of a major drop in the number of stars both east and south of Circini, and this is visually obvious some 1^O East of Circini. Astrophotographers using a 50mm. or 55mm. lens on a SLR will readily see the object. (Note: If you have already have a 55mm. photo that has Alpha Centauri and the Cross in it; you probably can see this in the bottom left hand corner!)

Bernes 145 / B145 (1449-6515), first named as recently as 1977, is the darkest globule in the region. This object is listed in Sky Catalogue 2000.0 but not drawn in the Atlas. The size of the 'hole' in an east-west direction is about 12'x5.0'min.arc. As a globule is given a Class 5 status, which is an indication of the opaqueness of the nebulosity. Class 6 is the most opaque and Class 1 is fairly transparent. In a telescope above 10cm. using a wide-field low power eyepiece, this dark nebula is just visible from the surrounding stars. Increasing the aperture, say 20cm., the object appears as a distinctive 'blank hole'. No stars are observed inside the patch to about 17th magnitude. On the eastern part of the nebula (following) is a yellowish 10.4 magnitude star, (GSC9015:1312) positioned at RA 14h49.3' Dec. -65^O15', that is not listed in Sky Atlas or Catalogue 2000.0. Surrounding this star to the west and north is the reflection nebula known as B145E or vdBH 63. I estimate the visual magnitude is about 14.5, as no magnitude is given for this object. The size of the reflection nebula is about 85"x 60"sec.arc. To find this reflection nebula would be tough for most amateurs unless you have the aperture. A 40cm. can probably see the wisps of nebulosity from a site like Wiruna, but a 50cm would really be needed to see it clearly.

Few interesting stars lie inside the larger dark nebula except for the pair Rossiter 3894 (RST3894). This star is easily found by drifting 0.8^O East of Cir. The magnitude of the two stars is 10.5 and 11.0, and separated by 2.2"sec.arc. at PA 160^O. The pair is easily visible in a 7.5cm. Little has changed in the positions since Rossiter first measured the pair in 1936.

NGC 5979 (PK 322-5.1/ SA2-124/ WRAY 16-187 / He2-135) (15477-6123) TrA is found near the southern boarder of Norma and the northern boarder of Triangulum Australe. This relatively bright planetary is contained in a starry field, having a photographic magnitude of 11.8 and a catalogued diameter of 8.0"sec.arc. The size is in fact more like 15"sec.arc., as David Frew states in AOST2. Visual magnitude of NGC 5979 is often stated as 13th in some references (like 13.01 in Sky Catalogue 2000.0) but it is likely 0.5 to 0.8 magnitudes higher.

In AOST2, the planetary is said to be faintly seen in the prism image in a 7.5 cm. I question this, because even in an O-III filter, I frankly could not see it. (Derived by an aperture reduction filter placed over the C-8.) A 10.5cm. can probably distinguish it from the starry field but an O-III would be a help. In the C-8, the planetary looked slightly mottled, with the edges very even and smooth. I could see no colour in this object, though a larger Dobsonian may see a hint of a blue. Its appearance is slightly elliptical, along PA 90^O- ie. East-West.

PNN is magnitude 15.3 and is invisible except for the largest Dobsonians. It has a mean radial velocity of +23 kms^-1 indicating that NGC 5979 is moving towards the Earth. The distant has been listed as 3 300 parsecs, but based on the metallic-emissions one recent reference states it is nearer to 3 600 parsecs. Again, little information is available - though it is better covered than its cousin NGC 5844. The STScI derived image of this object can be seen in Figure 3.

The Surrounding Field of NGC 5979.

NGC 6025 (Mel 139 Cr 296) (16037-6029) is an open cluster two degrees east and 10'min.arc. north of NGC 5979. As a cluster it can just be discerned as a lucid-spot to the naked eye and easily visible in any finder. The fourteen bright stars in this cluster are visible in a 7.5 cm. telescope. Larger telescope (>20cm.) reveals more stars, with about twenty-five being brighter than 14th magnitude in an area of 12'min.arc². Total integrated visual magnitude of the cluster is 5.1 and five stars are brighter than 9th magnitude. Brightest is the 7.3 magnitude star GSC 9036-2707. Deep astrophotography reveals about sixty associated stars, though some of the stars to the NW are not attached to the cluster. It is given a Trumpler classification of '2 3 r' - A weak concentration towards the centre with a large range in brightness and has a population that is rich.

At Bowen Mountain on the 23rd August 1997, Don Whiteman though it was "pretty neat and nice" through the Society's 45 cm. My personal belief is that the cluster is fairly elegant.

In reality, the cluster is about 2.9 parsecs (9 lty.) across, and has an estimated distance of 800 pc. (2 600 lty.). The age of this B3-spectral class metal-poor cluster, as calculated by the turn-off point on its colour-magnitude diagram, is calculated to about seventy million years. The cluster is slowly moving away from us at a small 3kms^-1.

194/ SLR 11 (15549-6045) is the stunningly brilliant multiple star, 1.0^O north-east of NGC 5979. The primary pair is SLR 11 (AB) has component magnitudes 6.5 and 8.8, separated by 1.3"sec.arc at a due east position angle of 93^O. To me the primary is yellowish, and the secondary is blue in colour. Spectrally this star is given as B9 II, but there is some doubt, ie. the WDS Notes, that suggests it maybe more like a 'K-type star. A 20cm. telescope, using medium to high magnification and good seeing will just easily separate the pair. 25cm or 30cm. will perhaps separate the pair more easily. Since the first measures by Sellors in 1891, the separation has slowly increased by 0.4"sec.arc. - with the last reliable measure made in 1962. The 'A' component is a suspected variable of unknown type (NSV 7310), with a small visual magnitude range of 6.11 to 6.15. It is also a known spectroscopic binary of uncertain period - making this a likely triple.

Two fainter yellowish companions are associated with the main pair that was discovered by Dunlop at Parramatta Observatory in 1832. The brightest lies north followed by the principle pair. 194 (AC) has the component 'C' is 9.1, some 45.0"sec.arc. apart at PA 48^O. Since the first measures by H.C.Russell in 1883, the separation has increased by 1.5"sec.arc. and the PA diminished by a mere 3^O. The second star is 194 (AD) lies south preceding. At magnitude 8.7, it is separated by 48.1"sec.arc at PA 225.7^O. Since 1883, the separation has diminished by 1.2"sec.arc.

Due to the small motion of these stars, little is known of the true connect of these outlying stars. The 'C' and 'D' components display opposite common proper motions. They maybe orbiting in a very long period - but it is more likely they are mere field stars.

In all this multiple makes an attractive set of stars in a prolifically starry field.

Footnote 1: Problems Identifying This Planetary (NGC5844).

The Guide Star Catalogue, designed to be used with the Hubble Space Telescope, is notorious for having errors with non-existent stars (c.20%) and misidentifications of known NGC and IC objects. Most of these have been ‘sifted out’ by observers like Brian Skiff, amateurs and professional astronomers by noting differences when observing objects. Fortunately, most happen to be faint objects.

This 7.6 magnitude bluish star (GSC9029:2732) stated in the catalogue proved to be a difficult object to explain.

In the GSC positions, according to the CDS listing of the catalogued position is 15h10m41.01 -64^O40'23.0". The source of the data is a taken with the UK Schmidt on March 1976 (Epoch 1976.256 ) using a IIIJ emulsion and a GC395 filter producing a derived magnitude was 7.61± 0.45. Visually, no star appears at this position nor in a number of other photographs of this region. The STSi image also shows no star. No star in this position is stated in the SAO or any of the preceding catalogues. Also the positional data of the centre of the planetary He2-119 and this 7.61 magnitude star is a mere 1.1"sec.arc North and 5"sec.arc. East, - well within the NGC 5844 boundary.

No asteroids were near this position during 1976 and no known variable stars. It is not in the New Suspect Variable (NSV) listing and no known nova is expressed for this object. It is obvious that a problem exists with this star.

Twenty three references were found during an Internet search with SIMBAD. Strangely, there is no reference to the PNN, nor of this star. The nearest star is GSC9029-1442 at magnitude 12.51±0.22 is stated at this position; 9"sec.arc.W, 43"sec.arc S; but and I could not visually identify this star either!

At first, it was compelling to think that this star is a novae or variable associated with the planetary.

After some checking (and extensive personal searching) a final reply ended the debate. This was received by via E-mail on Saturday 30 Aug 1997 from Gareth V. Williams the Associate Director of the IAU Minor Planet Center at Harvard University, Cambridge, MA;

"The "star" GSC 9029-2732 is actually an artifact of the plate measuring process and is simply a measurement of the "center" of the planetary nebula NGC 5844. Normally measurements of non-stellar objects would be so flagged in GSC, but this object appears to have escaped that classification. I note that NGC 5844 also appears in the USNO A1.0 catalogue, a list that is supposed to contain only stellar objects."

This apparent chaos seem likely because of the presumed non-existence of NGC 5844. If the catalogues are wrong, then observers will tend not to place it in their observing programmes. Although this proved not to be an ‘historical nova’, its final value at least will correct updates of catalogue listings. It proves that for all the technical marvels of modern astronomy mistakes still occur.

Interestingly, there remains one puzzling question that still cannot be explained; How could the magnitude of this "star" be measured at 7.6 if the planetary nebula has a visual magnitude is 12.1 and photographic magnitude of 13.2?

Footnote 2: Something is Seriously Wrong With Space.

(Title taken from Chapter 31 of Arthur C.Clark's: The Lost Worlds of 2001)

This field is strange to about 5^O surrounding NGC 5844. Firstly, the SAO catalogue has some stars placed in this region, while others, and sometimes brighter stars are not listed. For example, surrounding the region of NGC 5844 some other 9.5 magnitude stars are listed. Using my own versions of Atlas Australis and Uranometria 2000.0, I had some trouble identifying the actual field. Between the declinations between -64^O and -65^O, the SAO is both inaccurate and poorly surveyed.

The reason for this might be the original data in the production of catalogues in this region where the problem seems to have started with the beginning of the Astrographic Catalogue in the 1880's. Declinations to be surveyed were delegated to various sites. Those north of declination -64^O were delegated to the Cape Observatory in South Africa. South of -64^O this was allocated to both Sydney Observatory and Melbourne Observatory. The ‘Cape Catalogue’ was used to update the positions of stars to -64^{O . .}Later of the 50 000 stars, some 15% of stars were rejected because no data on their proper motions were given. In essence, stellar positions in the declination range of -52^O to -64^O have a few stars simply not listed. When the Astrographic Catalogue was eventually completed in 1936 - these rejected stars did not make there way in amateur atlases from the 1950 onwards. (Note: Some additional data used in the SAO is also taken from Vol.20 of the Ann. Cape. Obs. Catalogue by Jackson and Stoy. (1950.0))

South of -64^O, the details become very confusing. It seems that some procedural policies in producing the southern parts of the catalogue were different than at the Cape Observatory. Firstly, the magnitude limit is not as extensive from -64^O to the pole. Secondly, it seems that the first stars, and therefore the oldest positions, are in the region of declinations -64^O to -66^O. The data for these stars in the declination range were original made using the 'Third Melbourne General Catalogue, Reduced without Proper Motion to the Equinox 1900.0', eventually published by Ellery and Baracchi in 1917. Again, many stars without known proper motions were not eventually listed in the SAO.

What this means is that many earlier atlases before this time are relatively poor when identifying stars. If you own a computer program, such as RedShift 2.0 - notice the sudden drop off in stars in the declination range of -64^O to -66^O. (Make sure it is SAO orientated data and not based on the more realistic(?) GSC - Guide Star Catalogue.)

Amateurs identifying fields in this region should be cautious - especially object below c.7th magnitude. This includes the constellations of Pavo, Triangulum Australe, Circinus, southern Crux, northern Musca, southern Carina and northern Volans. Soon, the general introduction of the Hipparchos and Tycho catalogues to atlases will not have this problem with identification. This will reduce the uncertainties in this area to magnitude c. 11.5, but at the moment, no deeper.