Southern Doubles, Stars and Variables
10 Mar 2009
RA : 06h
Dec : -30° to -90°
Constellations : Col, CMa, Pup, Pic, Car, Men, Vol, Oct.
Best Observed : Nov - Apr (Text Ordered by RA)
RA : 06h
Dec : -30° to -90°
DS 00h 01h 02h 03h 04h 05h 06h 07h 08h 09h 10h 11h
NEW 12h 13h 14h 15h 16h 17h 18h 19h 20h 21h 22h 23h

Δ26 Dor
Δ27 AB / LDS 157 AC Pic
I 3 Pic
I 5 Pic
I 6 Pic
ζ CMa / Furud / 1 CMa / SMY1
JC 3 CMa
η Mon / 8 Mon / Σ900 Mon
Δ28 AC / HJ 3857 AB Col
JSP 868 Col
BU 753 CMa
β Mon / Σ919 Mon
Δ29 Col
Δ30 Pup
I 4 Col
μ Pic / HJ 3874 / Mu Pictoris
Δ25 ? / HJ 3869 CMa
I 178 (06349-3218) CMa
RR Pic / Nova Pictoris / FIN 74
Δ31 Pup
Δ32 Pup
ε CMa / Adhara /
21 CMa / CPO 7
ST Pic
EsB 188 / IV CMa
RR Pic / Nova Pictoris / FIN 74

μ Cep / Mu Cephei
λ CMa
α Pic


None Listed
ESO 121-6 Pic
ESO 365-10 Col
AGC 3390 Col
ESO 365-16< / PGC 19000 Col
ESO 122-11 &
ESO 122-11A Pic

Positions given as;
I.e. (13583-6018), are;
13h 58.3m
-60° 15'
This follows the current
WDS Conventions.

or arcsec
In arc seconds or
or arcmin
In arc minutes or
mas - milli arc seconds

( ° ) Angle in degrees.
Measured from
North through East

v - visual (naked-eye)
p - photographic
V - Photometric Visual
B - Photometric Blue
MV - Absolute & 10pc.

pc. - parsecs
ly. - light-years
AU - Astronomical Unit


T: Periastron (yr.)
P: Period (yr.)
a: Semi-Major Axis (arc sec.)
e: Eccentricity
i: Inclination
Ω: Orbital Node (°)
ω: Angle True Orbit (°)

R.A. 06 Hours

Δ26 (06122-6532) is one of the more interesting of the Dunlop pairs. It can be found quickly because in is in the same field as the orange-red 5.0 magnitude star, η² Dor / Eta (2) Doradus / HIP 29353 / SAO 249469 (06113-6535) whose spectral class is M2.5III. Δ26 is 6.8'ENE (PA 60°) from this star. Dunlop originally gave the stars as magnitude as 7,8. Modern day bright gives 7.1 and 8.5v magnitudes with the photometric ones being 6.86V and 8.07V. Presently (1994) the separation is 20.4 arcsec along position angle 119°. The WDS does not give Dunlop's measure as the separation is only guessed. The initial values are that of John Herschel in 1834 who measured 113° at 23.0 arcsec, suggesting the position has changed +5° and reduced in distances by 2.6 arcsec. I saw both stars as yellowish. Spectral classes are F6V+F7IV. Proper motions suggest that the stars are likely associated. Surprisingly E.J. Hartung missed this wonderful gem, but Graham Little in his series Ten O'Clock High says of Δ26;

Another fairly attractive double..., but again available to scopes 6cm and upwards. The primary star is an F5 type, appearing as a white, mag. 7.1... Lying 20.9 arcsec away (near enough the same separation as the two stars in Alpha Centauri) at PA 117 is the secondary star. It is a G type star and a good imagination can give it a yellow tinge. It glows with a mag. of 8.5. Keep the stars close for the best effect.

Only a few stars are seen in the fairly dull field with Δ26 itself being visible in apertures of 5cm. The surrounding field seem devoid of any interesting pairs of any interest to the amateur.

Δ27 / Δ27 AB / LDS 157 AC (06163-5913) is a strong yellow pair that lies in eastern Pictor. Both stars are 6.3v and 7.8v magnitude (6.44V and 7.76V) magnitude and are separated by 35.5 arcsec along PA 232°. This is an easy system even in 5cm or binoculars In 20cm I saw the colours as yellow and white. Since discovery these two stars have been diminishing 22.8 arcsec while the PA has increased 10° in the last 175-odd years of available measures. Both stars are likely unrelated as the proper motions in RA are moving in opposing directions and this certainly accounts for the apparent rapid motion. Hipparcos gives the parallaxes of A : 27.50±0.50mas ; B : 16.11±0.66mas giving the distances as 36.4±0.7 pc. and 62.1±2.5 pc., respectively.

LDS 157AC is the wider component of 14.2 magnitude that lies 40.7 arcsec away along PA 302°. Although as double stars go this is a wide and unlikely pair the proper motions with the primary (Δ27A) are -45 arcsec per century in RA and -320 arcsec per century in declination seem to suggest they are associated. The component was discovered in 1958 during the Luytens proper motion surveys. Seeing this companion requires 20cm or greater but is a bit difficult to see under the glare of the two other stars. Using an occultation bar in the eyepiece might help make this companion more visible.



I 3 (06125-6128) lies in southern Pictor and was discovered by R.T.A. Innes in 1894. It is interesting to note that I 3 is the first of the recognized catalogued Innes pairs, mainly because both I 1 and I 2 have been deleted from the WDS as actual pairs. This is a bit more of a difficult pair but it is at least easier than I 5 and I 6 that we have also examined within these pages. A 20cm is needed to split the pair cleanly. I 3 lies 4.4°W of α Pic / Alpha Pictoris or 2.3°S (PA 190°) of Δ27. Presently the magnitude are given as 7.1 and 7.6 separated by just over 1.0 arcsec along PA 5°. I saw the component colours as bluish and white. Since discovery the PA shows direct motion having increased by just over 15° over in the last century while the separation continues to widen from its original 0.8 arcsec. Based on the similar proper motions, though containing sizable errors, makes I 3 probably a real binary.

Using the parallax is 4.31±0.78mas giving the distance as 232±45 pc. or 756±141 ly. At this distance the projected separation is 236 A.U. or 3.5x1010 km. Stars of the given apparent magnitude give the absolute magnitudes as +0.27 and +0.77 suggesting masses of 5.6 M⊚ divided using the MLR Mass-Luminosity Relationship) as 2.9M⊚ and 2.7M⊚. Periods under these circumstances derive the overall period to be more than 1500 years.

Field of I 3

ST Pic (06140-6128) lies directly 11'W of I 3 and appears as a yellowish star. ST Pic is an RR Lyrae variable that changes between 9.3 and 9.8 magnitude in a period of 0.48574 days (11h 39.5m). Like the Cepheids, the rise in an RR Lyraes brightness is more rapid than the decline, increasing in 22% of the period or 0.1069 days (02h 23m).

ESO 121-6 / PGC 18437 (06075-6148) is a Sc spiral galaxy that appear as a 13.4p elongated gossamer smudge some 3.5'x0.5' in size that is aligned along PA 40°. ESO121-6 centre lies 41'SW of I 3 and is visible in 20cm with care but is easily seen in apertures above 30cm. The photographic image measures 4.2'x0.6'.

I 5 (06380-6132) appears in the southeastern part of constellation of Pictor as a yellow 6.2 magnitude star some 1.3° WNW (PA 287°) from α Pic / Alpha Pictoris. I 5 is a good example of an easy pair that has become impossible to view in amateur telescopes. When Innes discovered this pair in 1894 the separation was 1.7 arcsec along PA 270° for this 6.3 and 8.8 magnitude. This would have been easy target even for amateur telescopes. In the last decade the pair seems to be undergoing significant motion. Hipparcos in 1991 measured the pair as 0.762±0.002 arc seconds (PA 262°) yet by 1999 the distance has almost halved. Since this time the pair has continued to close and the separation has reduced now to an impossible 0.3 arcsec. Furthermore the position angle shows retrograde motion changing from 270° to 255°. This star will be interesting to watch in the coming decades when the separation will again increase by this time on the eastern side. Observations of the proper motions indicate that the star are connected physically. It is very likely this is a true binary system.

From the general data available the period is likely between 175 and 500 years. Using the parallax is 46.15±0.64mas finds the distance to I 5 is 28.67±0.30 pc. (1.4% error) or 70.67±0.98 ly. Proper motions are pmRA; -50.80±0.73 and pmDec; 72.69±0.66 indicating the stars are moving NW along PA 137°. Absolute magnitude are +4.62 and +7.12 and respective masses of 1.0 M⊚ and 0.6 M⊚.

Using the available data prediction of the motion of the components are listed in the Table below;

 Year   Sep.    P.A.   Year   Sep.    P.A.
       arcsec   deg.         arcsec   deg.
 1900   1.62   269.1   2005   0.22   254.1
 1920   1.35   266.3   2010   0.15   253.5
 1940   1.09   263.4   2015   0.09   252.7
 1960   0.82   260.6   2020   0.02   252.0
 1980   0.55   257.7   2050  -0.38   247.7
 2000   0.29   254.9   2100  -1.05   240.6

Comment: This predicts the minimum separation will be about 2023AD. However this leaves a problem with the Hipparcos measure as this point doesnt match the other points. If we reject this point, the prediction calculator shows that the 1999 measure matches many of the previous measures. (Note: The above is a linear interpretation and the observed results maybe different because of the eccentricity of the orbit and the inclination to the line of sight.)

I 6 (06425-6145) is also in southeastern Pictor but is a pair that is a challenge for the large amateur apertures. In some way this star by separation is mid-way between I 3 and I 5. The pair can be found between Alpha Pictoris and I 5, being either 42'WNW (PA 284°) of α Pic or alternatively 34'ESE (PA 113°) from I 5 (*See Below). This is a difficult pair as the 7.7 and 8.2 magnitude stars are presently separated by 0.6 arcsec along PA 257°. Since discovery by Innes in 1894, the PA has shown direct motion increasing from 230° to 257° (1997) - an increase of 27° or 2.6° per decade. Furthermore, the separation has halved in this time, changing from 1.1" to 0.6"arcsec. Presently this is not so easy to resolve and 30cm is likely required to see any suggestion of duplicity. By 2010 the stars will like merge as an apparent single star in amateur telescopes. If the motion continues as based on the sixteen (16) odd measures the pair will be closest in 2120 A.D. Unfortunately the available data on the system is too poor to calculate even rough parameters of the binary nature of the two stars, yet at least, the very similar proper motions suggests this is a true binary. Spectral class is F5 IV/V.

ζ CMa / Zeta CMa / 1 CMa / SMY1 / Furud / HIP 30122 (06203-3004) is a very wide but bright pair of 3.0v and 7.7v (2.96V and 7.81V) magnitude. It was noted and measured by Admiral Smyth in 1833 though it was certainly known as a wide pair by several earlier double star observers. Set along PA 338°, the two stars continue to widen from the 167.0 (1833) to 174.3 arcsec (1991). With a blue primary and yellow secondary the colours are certainly enhanced by their general proximity especially in small apertures or binoculars. This pair is likely an optical system.
Listed as star No. 395 in the 9th Spectroscopic Binary Star Catalog, the eccentricity of the orbit is 0.57 based on periastron on 2416508.0. It has an ω (argument of periastron) of 207° while the systems mean radial velocity is +32.2kms-1. This is a fairly poor grade orbit that was first published in 1941. ζ CMa A is a known long period spectroscopic binary with a period of 675 days. Spectral classes are B2.5V and K0V:

JC 3 (06203-2937) is a faint wide pair some 24'N of ζ1 CMa. This 7.9 and 9.3 mag. (8.04 and 9.36V) orange and yellow pair is separated by 13.3 arcsec along PA 207°. Little has change in the position, some +2° and +0.4 arcsec, since Jacob found the duo in 1846. Spectral class of the primary is estimated as K1III: Both star share the same motion so this maybe a true system.

EsB 188 / Herschel 20 / IV CMa / NSV 2945 / HIP 30409 / PPM 726310 (06237-2704) this 8.5v magnitude star is 29'ENE (PA 68°) from the galaxy NGC 2217. Described as intense red by William Herschel this deep red star is quite startling to the eye. I found by defocussing the star the colour becomes a little more obvious. EsB 188 first appeared as a variable star in the NSV Catalogue as NSV 2945 of unknown type that varies between 8.55V and 8.95V. In the recent GVSC4 the star has been accepted as IV CMa 140239 and recent observations have confirmed it is an SRC variable with the later fluctuations observed between 8.21V and 8.75V. These are typically semi-regular pulsating stars usually of late spectral classes which display amplitudes of about one magnitude anywhere between 30 days and 10 years. A classical example of the type is Mu Cephei.

μ Cep / Mu Cephei / The Garnet Star / HIP 107259 / SAO 33693 / PPM 39787 (21435+5847) that is located within the northern part of the bright nebula/ open cluster, IC 1396. Variations are 3.43 to 5.1 magnitude (mean mag. of 4.3v) shows an average period of 730 days. Spectral class is M2sIa while the B-V colour index is +2.242.

EsB 188 has the B-V colour index of+2.860 and is of spectral class C6II. The only observation I have seen is by Steve Coe, who saw EsB 188 it as Orange at 100X in [a] rich field.

Colour Comparison Stars of Late Stars Near EsB 188

While looking for EsB 188 I stumbled upon three red stars and three orange one in the next fields up and to the northeast. The parallax data on these (Stars 1, 4 and 5) (See Below) all these three stars is small and poor. A mean distance of all three stars in about 1.0 kpc. Stars 1, 2 and 3 all appear in a completely straight line along PA 290°. I have used all these stars as a useful comparison between orange and red stars. It is quite surprising how these stars have subtle differences in hue and found it a worthwhile exercise. I know of no other field that contain seven orange to reddish star within in a 1.6° field. Except for EsB 188, all stars are not known variable. The individual stars are;

Star 1 : HIP 30390 / SAO 171672 / PPM 250315 (06234-2623) is located some 42'N of EsB 188 or 57'NNE (PA 24°) in the next field using low magnification. This 7.2 magnitude star has a B-V colour index of +1.669 and is of spectral type of M1 III. This appears orangery-red to my eyes.

Star 2 : HIP 30461 / SAO 171693 / PPM 250340 (06242-2627) lies in the field is a 6.7 magnitude orange K0/K1III+ star appears in the same field some 11'ESE (PA 109°). [B-V of+0.948]

Star 3 : HIP 30288 / SAO 171642 / PPM 250283 (06223-2617) is a second 7.8 magnitude star (HIP 30288) also in the same field, but has a deeper orange colouration. This K2III, lies 17'WNE (PA 290°) [B-V of +1.358] HIP 30288

Star 4 : HIP 30657 / SAO 171751 / PPM 250399 (06265-2606) lies about 45'ENE (PA 68°) from Star 1 (HIP 30390). Although fainter at 7.7 magnitude, this star looks identical in colour to Star 1. The B-V is +1.644 and the spectral class is M1 III

b>Star 5 : HIP 30903 / SAO 171826 / PPM 250481 (06292-2607) lies further due east from Star 4 by some 34'. This star is the fainter of the tree at 7.9 magnitude and matches Star 2 in colour with the B-V of +1.633 and the spectral class of M3III.

Star 6 : HIP 30436 (06239-2525) is yet another orange star some 47'N of Star 1 or 49' from Red Star 4. This 5.6 magnitude star is a light colour than Star 1, 4 and 5 and has a spectral type of K5III and the B-V of +1.561

TABLE 1. CMa Orange Stars Comparison: Decending by B-V (Red to Orange)

    Star     Name      Position (2000)  Mag.   B-V   Spectral 
          RA      Dec. Class    
   EsB 188             06 23.7  -27 04  8.5  +2.860  C6 II    
   Star 1  HIP 30390   06 23.4  -26 23  7.2  +1.669  M1 III   
   Star 4  HIP 30657   06 26.5  -26 06  7.7  +1.644  M1 III   
   Star 5  HIP 30903   06 29.2  -26 07  7.9  +1.633  M3 III   
   Star 6  HIP 30436   06 23.9  -25 25  5.6  +1.561  K5 III   
   Star 3  HIP 30288   06 22.3  -26 17  7.8  +1.358  K2 III   
   Star 2  HIP 30461   06 24.2  -26 27  6.7  +0.948  K0/K1 III

η Mon / Eta Monocerotis / 8 Mon / Σ900 (06238+0436) is a very pretty white and yellow pair in a starry field about 12°N of Beta Mon or 8°E of Betelgeuse. Since discovered by F.G.W. Struve in 1831 the pair has been slowly diminishing from 13.9" to 12.7", but the PA has remained along 27° It was uncertain if these stars were associated, as said in Astronomical Objects for Southern Telescopes; 2nd Edition (AOST2) by David Frew and David Malin, but since the release of the Tycho / Hipparcos data, the respective parallaxes are 25.39±1.02mas and 41.09±10.14mas, combined with the RA and Dec proper motions which are moving in opposite directions, it is likely this is an optical double star. Σ900 is also possibly joined to the open cluster Dolittle 23 (Do 23) whose 18' size holds about ten or eleven stars. As AOST2 notes that 5'NW from 8 Mon is 9.7 mag star T141:2248:1/ SAO113805/ PPM150409. Described as red, I saw it as certainly orange or yellow-orange.
Owners of large Dobsonians may find in the same field the 14.7 mag, UGC3459 / PGC18964 (06240+4243), a Sc spiral galaxy whose visually size measures 30"x22". It is located 7.9' (PA 26°) which in the same direction as 8 Mon. I would be interested if anyone can see this object, as I can find no references in sighting this galaxy.

Δ28 / Δ28 AC / HJ 3857 AB (06240-3642) is an easy bright triple in Columba that is visible in small apertures or binoculars. Lacaillé was first to identify it as a pair, and when James Dunlop found it 1826 the wide components were assigned to the star 11 Argûs. Only later it was designated as Δ28 AC. It is located some 2.3°SE of the yellow 4.4 magnitude star, κ Col / Kappa Columbae. These two 5.7 and 6.9 magnitude components are presently separated by 63.9 arcsec along PA 74° (nf) (1991) and since discovery have slowly diminished from 69 arcsec and PA 64° (1826). I saw the colours as deep orange and deep yellow in a field devoid of many stars. Proper motions of these two suggest that this is just an optical system. Some 1.2'N of Δ28 AC is another faint 10.9 magnitude yellow star that enhances the pair.
Closer inspection of the primary finds the pair HJ 3857 AB. This companion is directly opposite the C component forming a straight line balanced in a ratio of about 5:1. At magnitude 9.8v, B is separated by 13.0 arcsec along PA 256°.

E.J. Hartung in AOST1&2 (#246) describes this triple as;

These are two bright orange stars 70 arcsec apart in this field sprinkled with stars; the brighter is south-west and has a companion described by Hartung as ashy, easily visible in 7.5cm. No real change has occurred since John Herschel's measures in 1836 and similar proper motion suggest a binary system.

I investigated this triple for the appearance of ashy coloured star (as well as HJ 3875 described below). (Ashy being the colour describing a greyish tint.)

How Dunlop missed this star is uncertain as it is clearly visible even in 7.5cm without any trouble. Since 1836 the pair has widened by 1 arcsec while the PA has decreased 4°. Looking at the proper motions it seems, unlike Δ28 AC, that HJ 3857 AB are associated, but if so, the period must be fairly long.

Fields Near Δ28

The visual field of Δ28 contains many faint galaxies, the brightest being the 14.7p magnitude, ESO 365-10 (06219-3633) some 26'WNW (PA 289°) This SA(s)b spiral galaxy appears visually as a small smudge some 1.5'x0.3' in size aligned along PA 107°. This was glimpsed under dark skies within the field using 20cm (65x). As for the other ten-odd 15th and 16th magnitude galaxies, a larger aperture is required which is made more difficult because of the brightness of Δ28.

Within the next southern field, some 50' containing the galaxy cluster AGC 3390 (06250-3720) which contains some sixty-three (63) galaxies within a diameter of 28′ of sky. This contains several galaxies bright enough for large apertures, however, I have not actually observed this. Some twenty-six (26) galaxies appear between 15th and 16th magnitude centred on the AGC position given above.

Only 1.8'NE of the given centre of AGC 3390 is the brightest galaxy ESO 365-16 / PGC 19000 (06252-3720) which is a faint 15.1p magnitude. This is a spiral galaxy with a small ring around it (Type: (R)SB(r)ab.) which would likely appear in >40cm like a smudge with two small condensation aligned almost NW-SE. In size this galaxy visually covers about 1.0'x0.4'.

JSP 868 (06257-3620) is the pair some 30'NW (PA 43°) which is contained within a 4.5' slightly bent line of four stars. The most northerly star of these is the brightest. This is HIP 30558 being 10.0 magnitude and distinctly yellow. Moving southwards the third star is JSP 868 that is made obvious by the 9th magnitude star merely 27 arcsec SSE (PA 158°) JSP 868 is listed as 10.6v and 10.9v (11.0V and 11.4V) which is divided by 4.8 arcsec along PA 230°. Clearly split in 20cm (127×) the two would be visible with care in 10.5cm. To me the stars looked wider than this by perhaps as much as 0.5 arcsec. Few observations have been made of this duo so it is uncertain of their relationship and the latest proper motions are a least borderline.

BU 753 (06287-3222) lies some 54'WSW (PA 247°) of HJ 3869. BU 753 is easy to find as it lies 14'NNE (PA 26°) from the bluish 4.5 magnitude star λ CMa / Lambda CMa / HIP 30788 / SAO 196857 / PPM 282725 (06282-3235). This pair has remained relatively fixed at 1.2 arcsec but the PA has marginaly reduced from 47° to 43o since found by S.W. Burnham in 1892. Visible in 10.5cm the moderately close pair appear in a fairly drab star field. Spectral class is B4Vnpe.

β Mon / Beta Monocerotis / Σ919 (06288-0702) is a triple system. The closer "BC" pair magnitude 5.7 and 6.2 and is separated by 3.0 arcsec along PA 107° The "A" component is 5.1 magnitude and is some 10 aarcsec away at PA 125°. Another 12th mag star, making the AD pair (BU 570), is 25 arcsec apart at PA 56°. Although invisible to amateur eyes, the companion of the "C" component was discovered as recently as 1988. Known as CHR 167 or "Cc"; the 5.6 and 6.1 mag stars are separated by 0.3 arcsec along PA 141° This makes Beta Mon possibly quintuplet. It is certain that the four stars are associated, but the "D" star is still undetermined. All stars are of B-spectral type, and are coloured light sapphire blue. This system is very attractive and not one to miss!

Δ29 (06291-4022) is a wide optical pair in south-eastern Columba lying some 3.2° NNW (PA 330°) from the blue 3.2 magnitude star, ν Pup / Nu Puppis. Assigned as 21 Argûs by Dunlop, this orange pair is listed as 7.5v and 7.9v magnitude (7.70V and 7.98V) and is separated by 64.8 arcsec along the roughly east-west position angle of 118°. Since the time when it was found by Dunlop in 1826, the separation has dropped from 71.7" to 64.8" and increased from 109° to 118°. (1991). The field is moderately starry especially to the eastern parts and several 6th magnitude stars lie within 1°. An easy object even in 5cm or binoculars.

Δ30 (06297-5014) is placed some 3.2°W of Tau (τ) Puppis, or 2.6'N and a little east of Carina's Canopus. The magnitudes of the yellow and red-orange pair are 5.2 and 9.0, separated by 11.7 arcsec at PA 313°. Δ30 is a multiple star with both o the main components show companions. Δ30 AB has an orbital period of 53 years, and the equal 6.0 magnitude duo can be seen in 20cm. Presently the AB system is separated by 0.8 arcsec (2003) whose PA is c.240°. Another invisible component ABb is suspected. Δ30 CD has a longer period of 102 years, however, it is far more difficult to see. Presently the separation is merely 0.5 arcsec, which will slowly increasing to 0.6 arcsec by 2017. Both equal brightness stars are reddish. This CD component should be visible due south in 30cm to 40cm with care, requiring high magnification.
No doubt all the components of this the multiple system are gravitationally connected, being likely a quintuplet system.

I 4 (06307-4027) is a nearly fixed pair in the same field as Δ29 some 17' ESE (PA 103°). In the constellation of Columba, this distinctly blue star is separated by 0.8 arcsec along PA 306°. Innes discovered this pair in 1894 while likely inspecting Δ29, as he likely did with I 3, I 5 and I 6 with Δ27. The stars are listed as 6.7v and 6.9v magnitude (7.28V 7.50V), however, since discovered, the stars have moved along 4° in PA. In 20cm (333x) the two Airy disks were separated in good seeing and I am quite certain that smaller apertures would have far more difficulty. Another deep orange star lies 8' almost due south from I 4.

μ Pic / HJ 3874 / Mu Pictoris (06320-5848) is a bluish and white and pair in an unremarkable field some 6°S of Canopus and about two-thirds the distance between Canopus and Alpha Pictoris. AOST2 says ...7.5cm shows with close attention. I have seen this pair in 20cm, 10.5cm and 7.5cm over the years, and I suggest that the 10.5cm clearly separated the duo without too much difficulty. It would assume that any 7.5cm would need good seeing to view the pair because of the moderate difference in magnitude. Presently (2003) each of the 5.7 and 9.4 magnitude components are separated by 2.5 arcsec along PA 230°. Little has changed with the eleven observations to date (2003) regrading the relative positions. John Herschels measures are questionable and the IDS in 1961 through to the WDS03 continue to quote the 1894 measures. In comment, it is surprising how Dunlop missed this pair, because it was well within his grasp and certainly bright enough.

Lawrence Hargrave observed the pair from Sydney Observatory on the 12th January 1879 stating Seen: but did not measure, however, I doubt he was looking at the right star, because he describes the magnitudes as "6,12" - decidedly underestimating the companions magnitude - as John Herschel did in 1836. Hipparcos found the parallax of 4.50±0.50mas with little proper motion giving the distance as 222±11pc. (or 725±82 ly.) The measured separation was 2.488±0.023 arcsec along PA 2300 - the 1991 values in the WDS03. It remains uncertain if these two stars are really associated, but if they are, the absolute magnitudes are -1.0 and +2.7, respectively, with the masses around 4.1 M⊚ and 1.7 M⊚. Projected separation of 550 A.U. (8x1010 ly.) gives the period around 5½ thousand years. Combined spectral class of the pair is B9Ve. Mu Pic is listed as HIP 31137 / SAO 234564 / PPM 335251 with a 5.69V magnitude and the B-V of -0.057.

Δ25 ? / HJ 3869 (06326-3202). Dunlop gives Δ25 position as 06h 12m 05s -32° 06' (1825) or 06h 18.6m -32° 10' (2000) No pair exists in this location and there are no realistic candidates here. It is likely HJ 3869 is the duo Dunlop is talking about. HJ 3869 is some 3.0°E (PA 88°) from Dunlops precessed position for Δ25s of 06h 18m 26s -32° 09m 55s (2000). This is likely just a transcription error by Dunlop but his catalogue leaves few clues, other then the magnitudes of 6,8 for the components, of Δ25. This pair is very likely HJ 3869 as it matches the pairs magnitudes quite well. Located in southwestern Canis Major, HJ 3869 can be found some 3.3°SE (PA 127°) from the blue 3.0 magnitude ζ CMa / Furud (06203-3004).

Magnitudes are 5.7 and 8.7 (5.68V and 7.87V). I thought the visual magnitude for he secondary was a bit brighter than the visual magnitudes given above - perhaps more like 8.0 - that agrees with the photometric magnitudes. Separation is presently 24.6 arcsec along 258° (1991). Since discovery the pair continues to close while the position angle has increased some +8°. This blue and white pair matches well with the B2IV and A0 spectral type, however, the PPM star catalogue oddly gives the spectral class as F0. It is still uncertain if the stars are attached. HJ 3869 is visible in small apertures and is a delightful pair to search for and find. An orange star 7th magnitude star lies some 15'SW in the same star field.

I 178 (06349-3218) is a close pair in Canis Major that is presently separated by 0.9 arcsec along PA 194O (1991). Innes discovered this pair in 1897 and the pair is placed 34'ESE (PA 119°) of HJ 3869 - Δ25?. The pair is just visible in 20cm at high magnification if the seeing is good, but 25cm or 30cm would be certainly be more preferable.

Although the pair has fractionally widened while the position angle shows retrograde motion and has deceased by 10° in a century. Proper motions are similar so it is likely these is a real system. Spectral class is B5IV.

RR Pic / Nova Pictoris / FIN 74 (06356-6238) was a very bright nova that was discovered on the 25th May in 1925 by R. Watson from South Africa. Nova Pictoris is positioned some 1.6°WSW (PA 242°) from 3.2 magnitude Alpha Pictoris which for a month or two outshone this star.

FIN 74 (06356-6238) is listed in the WDS03 as a multiple star whose B, C and D components are actually the brighter portions of the ejecta being flung into space in the year immediately after fading from view. This is similar process, as the WDS Notes state, ...similar to those made by Kuiper for Nova Herculis (1934)- so FIN 74 is therefore not a multiple star at all.
Finsen made the observations several random sets of observations and measures between 1928 and 1934 after the nova had faded below about 10th magnitude. The positions of these brighter fragments were given in 1928 as B 72° 0.5 arcsec, C 241° 0.4 arcsec and D 356° 0.3 arcsec, with the B and C components being 12.8 and 13.5 magnitude, respectively. This is roughly distributed in a Y formation. From the later observations it was concluded that the material was travelling about 0.2 arcsec per year, and Finsen showed the general motion of the material by further measures during 1930, 1934 and 1935.
RR Pic is listed as variable star 0634-62 and appears on the RASNZ Chart No. 269 and No. 270. RR Pictoris is now a star of 12.5p and maybe a recurrent nova - hence the availability of the RASNZ variable star chart. Nova Pictoris was one of the first novae to be scientifically observed by astronomers.

Δ31 (06387-4813) is another bright pair some 2.5°NE of Δ30 or 3°NW of Tau Puppis. Discovered by Dunlop in 1826, the components are 4.9 and 8.2 mag, separated by 13 arcsec at PA 320°. The pair reminds me very much of Δ51, with a small magnitude difference. I saw the pair also as orange and white. No change has been observed with the pair, so the true connection remains uncertain. The field is quite pretty.

Δ32 (06423-3824) lies near the western edge of Puppis, close to the Columba border, some 7°W then 1°S of Pi (π) Puppis (Δ43). Comparing the field to the other ones in this article, this field is quite spartan. Both stars are white and 6.5 and 8.0 amgnitude, respectively. Since the first observations in 1835 both the PA and separation have remained fixed at 276° and 8.0 arcsec. A 7.5cm should see both stars with care, though 10.5cm would be much easier.

α Pic / Alpha Pictoris / Apictor / HIP 32607 / SAO 249647 / PPM 355624 (06482-6157) is a white 3.24 magnitude star located in southwestern Pictor and is placed 22'W of the border with Carina. Hipparcos parallax is presently given as 32.96±2.14mas giving the distance as 30.34±1.98 pc. or 98.96±6.45 ly. At this distance with the B-V of +0.225, the absolute magnitude is +0.83. If the spectral class is A7 IV, then the surface temperature is 7 810K giving the stellar mass as 2.6M⊚ and the radius of 1.9 R⊚. Proper motions are pmRA -68.39±2.34 pmDec; 242.03±2.29 mas; giving the general cpm of 251.6 mas per year along 344° PA. α Pic is very similar in nature to the 1st magnitude star Altair or Alpha Aquilae.

ε CMa / Epsilon CMa / CPO 7 / ADS 5654 / 21 CMa / Adhara / HIP 52089 / SAO 172676 / PPM 251347 (06586-2858) is the 22nd brightest naked-eye star in the sky at 1.5v (1.53V) magnitude star whose absolute magnitude (Mv) is -4.4. In size, the primary of Adhara is 22 times the diameter of the sun or some 7.6 million kilometres. Stellar interferometry has measured the diameter between 7.2x10-4 and 7.5x10-4 arc seconds. Surface temperature of 23 000K is calculated from its spectral type. B-V is -0.132, while the luminosity class is B2II. A parallax of 7.30±1.80, with very little proper motion, calculates the distance as 140±36pc. or 447±117ly. (Burnham says Mv is -5.0 and 680ly.) ε CMa shows several oddities such as being surrounded by a circumstellar shell and having the colour excess E(B-V) of +0.02. Based on the general distance and motions, ε CMa is possibly a member OB group near Omicron CMa being a stellar member of the open star cluster, Collinder 121 (#34).

ε CMa is the moderately close pair CPO7 was first found in 1850 by J. Maclear from the Cape Observatory in South Africa. Separation for the 1.5v and 7.5v magnitude stars is presently 7.0 arcsec along the fixed position angle of 161° (2000). In the 150 years still the most recent measure in the year 2000 the pair looks like it is continuing to become closer. When measured In 1850 the separation was 7.7 arcsec and 7.5 arcsec in 1950. Like Rigel / Alpha Orionis (05145-0812)(0.3 / 10.4 9.5 arcsec,201° B8Iae:) this pair is difficult to resolve because of the overwhelming glare of the primary hiding the much fainter secondary. Little information is available to declare if the two stars are associated - though one or two sources say this is an optical pair based in the differing velocities (v sin i) which is 54kms-1. Projected separation is 1600 AU.

ESO 122-11 and ESO 122-11A (06591-5908) are two strongly interacting galaxies that can be found 32'W of Δ39. *(See Below) Both galaxies can be seen in telescopes greater than about 20cm in dark and moonless skies, but may be more difficult to see because of the two nearby 6th magnitude star. Observers might like to take the two stars out by move the telescope to the southwest to eliminate from the field some of their overwhelming light.

Both of the galaxy centres are separated by only 6.4 arcsec aligned NW to SE. Apparent sizes of these two galaxies are given as 0.8'x0.4' and 1.0'x0.6' (48x18 and 60x36 arcsec) but I would expect you would see only about half to one-third of this. I.e. 24"x9" and 30"x18"arc seconds.

Looking at the red image, you can clearly see the two separate galaxies. Incidentally, the visual image is merged because of the overexposure, but in allows you to see the effects of the interaction with the tail pointing to the west. These galaxies were taken by Sue Triton on 13th January 1978 starting at 10h 44m PM using the then UK Schmidt Camera atop of Siding Spring - the Observatory of the Anglo Australian Observatory. The Plate Number is J3870 and was made during the 7.5 minute exposure.

Do you see in the telescope two galaxies or just one big nebulous mass? Can the cores be resolved or not? What aperture is needed to do this?
Little is known about this interactive pair except the radial velocities are 8 360 and 8 182 kms-1, respectively, giving a mean distance of about 127 MPc (or about 415 million light-years).

NOTE: By coincidence the pair Δ7 in Horologium, four hours less in right ascension, has the interacting galaxies ESO 115-25 and ESO 115-25A near it. These are near the galaxy NGC 1096, which are all likely part of the same multiple-galaxy group. If you are interested in these double galaxies, it might be worth seeking out ESO115-25/25A on the samenight.

Southern Astronomical Delights”
© (2009)
10 Mar 2009