Southern Doubles, Stars and Variables
10 Mar 2009
RA : 07h
Dec : -30° to -90°
Constellations : CMa, Pup, Car, Vol, Men, Cha, Oct.
Best Observed : Dec - Apr (Text Ordered by RA)
RA : 07h
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

HJ 3921 Car
Δ38 Pup
Δ39 Car
RST 4340 Car
R71 AB / SLR 22 BC Pup
HJ 3947 Pup
I 7 Pup
Δ43 / π Pup
JC 10 Pup
R 75 Car
Δ47 CMa
Δ49 CMa
Δ51 / σ Pup
COO 49 CMa
Δ50 Pup
RST 2482 Pup
HJ 3982 / p Pup
HJ 4000 Car
Δ55 Car
HJ 4002 Car
Δ56 Pup
R 79 Car
HJ 4018 Car
Δ59 Pup

PR Pup
L2 Pup
RR Pup Pup
NR Pup Pup

None Listed

None Listed
Sa 2-6 / PK 258-15.1 PNe Pup

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. 07 Hours

HJ 3921 (07006-5824) lies in a fairly spartan field 50.8' (PA 336°) from Δ39. This faintish pair is listed as 8.3 and 11.5v magnitude, being separated by 5.8 arcsec along PA 272°. Since first measured by Innes in 1911, little has changed in the relative positions, and from the merger data available, it remains uncertain if the two stars are connected. HJ 3921 is easily seen in apertures as low as 7.5cm, but is nothing to write home about. If it were not so easy to find to the north of DUN 39 - I might not have even mentioned it.

Δ38 (07040-4337) is a triple system half-way between Sigma (σ) Puppis (Δ51) and Nu (ν) Puppis. Unlike most Dunlop pairs, the primary AB system is yellow and orange. Since discovery in 1836, the pair has continued to slowly widen by 0.8 arcsec and increased in angle by 5°. The separation now is c.21.3 arcsec at PA 125°, both stars being with 5.5 and 6.8 magnitude. It is likely that these two are physically associated as they have similar proper motions and parallaxes. Inspection of the field finds another bright yellow star preceding the main pair. This is the so-called Δ38 AC and wider than most, but since 1900, this star has reduced in separation from 184.8 down to 136.1 arcsec (1977), changing phenomenally by 0.63 arcsec per year! Also the PA has changed from 334° to 282°. I estimated the current positions as 115 arcsec at PA 250° (2001). This star is assuredly not physically associated with the AB system. In this case, the apparent motion is not this star, but actually due to the doubles high proper motion and parallax. Using the Hipparcos data the average proper motion is -102.95 arcsec per century (1.72' per century) in RA and 392.71 arcsec per century (6.55' per century) in declination. This motion, however, is not the quickest in the heavens as 61 Cyg moves almost ten times faster. Observers might like to compare sketches over a number of years to physically see the motion for themselves. Distance to Δ38 AB is 15pc or 49±2ly.

Δ39 / DUN 39 (07033-5911) is a stunningly bright southern pair that lies in Carina, some 1.5°E of the mid-eastern Pictor border and 8.4°NE (exactly) (PA 315°) from the second brightest star in the sky, Canopus. It can also be easily be found some 3.3°NW (PA 35°) from the 3.2 magnitude Alpha (α) Pictoris. The field itself contains a yellowish 6.0 magnitude star, some 22'NE (PA 310°) away that has another two fainter companions (11th and 10th magnitude) in a slightly crooked line. These latter stars will correctly identify the field.
This is one of the very best of the Dunlop pairs discovered from his home Parramatta in 1826. Listed also as 89 Argûs, using the old Bode Numbering System that is similar in nature to the Flamsteed Numbers, Dunlop gives the magnitudes as6,7 at 1828 co-ordinates of 07h 01m 13s and -58° 55'.
Δ39 has the naked eye combined magnitude of 5.1 whose component magnitudes are each 5.50v and 6.52v (5.83V and 6.78V) magnitude. Separation is presently 1.4 arcsec along PA 86° (1997). Since discovery, the pair continues to become a more difficult as the separation has decrease from 2.5 to 1.4 arcsec. I.e. Innes measured the pair from South Africa in 1912, finding the positions as 80.7° and 1.9 arcsec. Furthermore, the PA has continued to progressively increase from 76° to its present 86° (1997).
Using the available Hipparchos data, which I have assumed is correct, finds that the pair's distance from the Sun is 147±7pc. (481±24ly.) - calculated from the 6.77±0.34mas parallax. From this, the true stellar separation would be around 216 AU (3.2x1010 km.) apart, each have respective higher luminosities than the Sun of 118x and 46x with the absolute magnitudes of -0.35 and +0.67.
Association of the two components is almost certain, as the proper motions are not too dissimilar, indicating the stars are moving southwest toward PA 220° at some 14.84mas per year. Visually I have seen this pair several times and each time I saw the pair as bluish and yellowish. These observations are contradicted by both Gould and E.J. Hartung (See Below) who both call them yellowish. Looking at the combined spectral class of B9IV and the B-V of -0.125, it is hard to see how this pair could be described as yellowish at all. Could the colour of the other bright field star be influencing these observers?

Δ39 Descriptions

H.J. Hartung says in AOST1&2;

[A] 7.5cm will readily resolve this bright pale yellow star, and the components have shown a very slow approach and increase in angle since John Herschels measures in 1836, and common proper motion indicates they are connected.

Ross Gould ("Southern Astronomy"; Mar/ Apr 1994 pg.52-53) says of Δ39;

A test for 8cm refractors, and not difficult with 10cm scopes. A pale yellow pair, of mags 6.0 and 7.1... In 1952 it was at 1.7 arcsec, PA 82°.

RST 4340 (07091-5905) is a double star that is near impossible to see in any amateur telescope. It lies some 44.6'E (PA 84°) within the next field from Δ39. For the record, this 9.4 and 10.0 magnitude very close pair was discovered by RST 4340 is separated by 0.1 arcsec along PA 339° (1991). The PA has continued to decreased from 73° (1940) to 339°, some 94°, thus moving from Quadrant 1 to Quadrant 4. The primary is identified as HIP 34810, and has a parallax of 7.98±0.95 displaying significant proper motion in both RA and Dec. Last measure in the WDS02 is the Hipparchos one, giving the PA as 339° and the separation as the amazingly precise 0.147±0.013 arcsec. The companion of RST 4340 is not listed in the Hipparcos Catalog but does appear in the Tycho Catalog as T 8562:1688:1. Using these values, the distance is 125±15pc., separating the stars by some 18AU or 2.8 billion kilometres. Both these stars must be approximately similar in mass to the Sun, with the absolute magnitude of +3.9 and +4.5. No doubt this is a true binary star.
What drew my attention to this object is that the 8.9 combined magnitude deep G5V yellow 'star' is the WDS unlisted 10.3 magnitude reddish-orange companion whose colours made this surprising interesting visual pair. This companion (perhapsRST 4340 C) lies 42.7 arcsec away along PA 292°. This is not listed in the HIP Catalog but is in the Tycho Catalog, giving the magnitude as 10.34V and the significantly larger parallax of 51.80±26.20mas. This star is not likely to be associated as the proper motion in declination travels the wrong direction.
There are also some other colourful stars in the same eyepiece field. First is the orange 8.35 magnitude K1III star, HIP 34618 / SAO 234989, some 10.1'NW (PA 56°) from RST 4340. A second orange 8.31 magnitude K1 III star is HIP 34674 / SAO 234999, which lies either 9.6'NW (PA 33°) from HIP 34618 or 19.5'NW (PA 44°) of RST 4340. Both these stars seem unrelated even though the colours, magnitudes and spectral types are quite similar. To contrast these two orange stars is another 8th magnitude blue star 8' due East of HIP 34674, which at low powers lies on the eastern edge of the eyepiece field if centred on RST 4340. In all, these stars only add to an already attractive scattered field of many faint stars.

L2 Puppis (07135-4439) is commonly an example of a starting variable star for new observers. Some 3°SW of the star Sigma Puppis, finds this orangey red variable is nearly always visible to the naked-eye. First discovered by Gould in 1872, it type is a semi-irregular SRb variable with the mean period that varies over c.141.9 days while the magnitudes ranging roughly from 3rd to 6th magnitude. It is not unusual for it to be brighter than this maximum on occasions. I.e. L2 Puppis has brightened once to 2.6 mag, or faded to 6.2. Its spectrum varies from M5 to M6 and shows unusual emission lines.
This variable is also listed bythe GVSC classification as 071044 based on star positions in 1900. The variable appears in the comparison chart of RASNZ Series 1 Chart No. 8.
L2 Puppis is also the wide double star HJ 3943 that is often missed in many common references. The components in the WDS03 give the 5.1 and 9.5 magnitude stars a separation of 62.0 arcsec along PA 214° which was measured in 1913. HJ 3943 B can be found using the GSC data. This identifies for GSC 7642:279 finds the separation is presently 1.4' (84 arcsec) along PA 221°. The GSC gives this star 11.5V magnitude much fainter than the given 9.5v. Another brighter 10.55V magnitude yellow star, T 7642:1891:1 / GSC 7642:1891 (07137-4439) also appears 1.5' (90 arcsec) away along PA 144°. From the available data and the observed separation this is likely just an optical pair.
[Version 2 12/11/03]

R71 AB / SLR 22 BC (07144-4440) is a white triple star some 8.6'E (PA 99°) of L2 Puppis. R 71 AB is the brighter of the two that contains the 9.6 and 10.2 (9.61V and 9.77V) magnitude stars separated by 15.9 arcsec along PA256°. R71 suggests it has shown some change in the positions, reducing in PA from 288° to 256° and 18.4" to 15.9" in the last 125 years. (2004) Russell, incidentally, gave the magnitudes as 10,10. R71 was discovered by H.C. Russell just before midnight on the 1st April 1879 (1879.248) and then measured as 15.39 arcsec along PA 77.465°. It seems that he evaluated the brighter component incorrectly so the position angle had 180° added to make the new PA as 257.465 or 257.5°. However, the WDS03 gives this 1879 separation here as 288° and 18.4 arcsec which does not match the RussellsSydney Observatory List of New Double Stars that appears written in the 1881 publication. At the time of writing the values are being investigated by the USNO, but it does seem that something is quite wrong with the WDS03 figures or that another observation was made in 1879 by another observer preceding Russells own discovery. In the earlier versions of the WDS, the 1879 position is given as 15.2 arcsec along PA 256° - matching Russells observations. His position angle has likely been precessed from the time of Russells original measure. Another possibility is that this is the 1935 measure and not the 1879 one, as the older versions of the WDS state the same scalar measures.

SLR 22 finds that the R71 B is again double. C is 11.2v (10.90V) magnitude being separated by 1.7 arcsec along PA 257°. Since discovery by R.P. Sellors at Sydney Observatory in 1896, the position angle has reduced from 266° to 257° while the separation remains fixed.
Common proper motions suggests that SLR 22 is likely a true binary star but the brighter A component is a optical companion. All three stars form a straight line proportioned by a ratio of about 9:1. Spectral classes are A5, A5 and A7III, respectively. The whole system is visible in 7.5cm and contrasts nicely with the orange-red colour of L2 Puppis in the field.


Sa 2-6 / Wray 17-1 / Longmore 3 / ESO 256-19 / PK 258-15.1 / PNG 258.0-15.7 (07148-4657) is an 11.8 magnitude PNe some 82.0 arcsecond across that appears in the same field as I 7 - some 46'NNW (PA 346°) away. It can be located using L2 Puppis by moving the telescope 2.3°S (PA 174°). The PNe form as flat equilateral triangle with the 5.6 magnitude orange star HIP 35181 / SAO 218589 (07163-4646) at the apex. This star is 18.5'NE (PA 55°) away. Unfortunately there is another 5.7 magnitude bluish star merely 6.4'N (PA 354°) which interferes with the faintness of the nebulosity.
This star is the ACV variable PR Pup (07148-4651) which varies between 5.69V and 5.74V magnitude in the period of 1.9347 days. (Its spectrum is A0p(Si)) Yet another star interferes with the PNe.
This second stars is the yellowish 4.5 magnitude HIP 34834 / SAO 218537 (07126-4646) that lies 26'WNW (PA 298°). It would be best to eliminate this star from the field as the star bright will obscure the PNe Sa2-6 itself.

HJ 3947 (07166-4614) is a medium close pair of 8.0 and 9.9 magnitude separated by 8.0 arcsec along PA 270°. Located 45'N (PA 348°) of I 7 or alternatively 1.7° (PA 161°) from L2 Puppis. Little has changed since Lawrence Hargraves first measured the pair on the 4th April 1881. This white pair is fairly easy in small apertures and is a good example of a nice faintish southern pair.

I 7 (07175-4659) is within the constellation of Puppis some 2.4°SSE (PA 163°) of the semi-regular variable star L2 Puppis. Innes discovered the moderately close pair in 1894 for this 6.7v and 7.9v magnitude (7.1V and 8.4V) pair being presently separated by 1.1 arcsec along PA 209° (1998) This pair continues to decrease slowly in separation from it original measure of 1.5 arcsec while the PA shows retrograde motion that has changed from 220° to todays 209° - roughly 1° per decade. At present the pair is visible in 15cm using moderate to high magnification, but over the next century the separation will continue to become more problematic for amateur observers. I 7s spectral class is K3III matching the yellow-orange primary seen in the telescope. Proper motions are similar suggesting the pair is attached.

Δ43 / Pi (π) Puppis (07171-3706) is easy to find as it is the brightest star in a small triangle of stars, some 7.4°S of Eta CMa, whose common name is Aludra. Pi Pup is separated by 69.2 arcsec at PA 213°, while the magnitudes are 2.7 and 8.0. Observations since 1826 has seen little changed in the positions. I saw the colours as deep orange and blue, making one-hell-of-a contrast. I place this as 3rd or 4th in my Top 10 of southern contrasting, perhaps just behind the magnificent x Velorum (Δ95)(10393-5536) in SE Vela. This field is just remarkably memorable.

JC 10 (07183-3644) was discovered by W.S. Jacob in 1846 appear in the next NW field. Both these blue stars are 5.1 and 8.7 magnitude and separated by 117 arcsec at PA 216°.

R CMa / R Canis Majoris (07195-1624) is located 8.4°W of Sirius. It can be found 1.2°S of the 9th magnitude open star cluster NGC 2360 containing about fifty stars between 9th and 11th magnitude. This eclipsing binary is listed as semi-detached, suggesting that it is almost an EB system. Magnitude variations change between 5.70 and 6.34, with the period of 1.1359405 days where the primary minima varies by 0.64 magnitudes, while the secondary minima dips only 0.08 magnitudes. The periods length is suspected to vary discontinuously.
Recent calculations place the mass of the system as 1.20 M⊚ and 0.20 M⊚ (1989). W. Heintz in Double Stars (1978) states that the masses of the stars are respectively 1.80 M⊚ and 0.2 M⊚, with the secondary that appears very extended. It is likely that mass transference through the Roche Lobe has occurred in the past, and may still be continuing, with the primary being the youngest star. The individual luminosities are 2.8 L⊚ and 0.1 L⊚, with surface temperatures of 6 110K and 3 110K. True distance between the two stars, surface to surface, is 3.5 million kilometres, with the respective individual diameters of 2 million and 1.7 million kilometres. Spectral classes are listed as F1V and K1VI while distance is 27pc or 88 ly.

R 75 (07216-5521) is a triple star containing a moderately faint close pair and another wider faint component. Located in some 8°E of Canopus, and roughly half-way between Canopus and the open star cluster NGC 2516 at the bottom of the false cross, this system is a faint portion of sky beyond the boundary of the Milky Way. Since discovered by H.C. Russell in 1880, there has been some motion in the main AB pair. When first found the three stars were in a straight line, however the movement of component B has changed from PA 268° to PA 272° making it slightly more bent than any straight line.
R 75 AB is the inner pair is visually given from previous observers as 10.0 and 10.6 mag. with the Tycho values being 10.43V and 11.28V magnitude AB is separated by an unchanged 5.1 arcsec. The primary seems to be F3 III: star.
R 75 AC is some 30.8 arcsec wide along PA 262° yet has hardly moved since discovery. R75 C is given as 11.47 and 10.4v being a whole magnitude different! When I last observed this pair in 1985, I saw all the colours as both yellowish, however, this was a bit harder to discern properly because of the faint magnitude of the stars. It is possible that the inner pair are associated, though there is some doubt about the wider component.

Although this triple wont set 'the world on fire' its linear nature of the three stars is unusual. Proper motions for the three stars are similar, so this is likely a real system.

Pair           Sep.      P.A.   Comp-    Mag. 
              arcsec     (o)    onet     (v)  
R 75 AB        5.1       272     A      10.43 
R 75 AC       30.8       262     B      11.28 
R 75 BC       25.8       260     C      11.47 

Δ47 / DAW 129 (07247-3149) is a wide yellow and white pair just inside the southeastern Canis Major border some 52' due west of Δ49. Both stars are 5.3 and 7.6 magnitude and are separated by 99.2 arcsec at PA 342°, and can be seen even in binoculars. Like Δ30, both components are again double. The brightest component, the "AB" system, was discovered by B.H.Dawson in 1922. Known as DAW 129, the pair is certainly difficult in apertures less than 25cm. At 5.3 and 11.0 magnitude, the stars and are separated by 1.9 arcsec along PA 309°. The fainter component in the "CD" system was discovered by W.H. van der Bos in 1929. The "D" component is 10.8, some 3.2 mag fainter than "C", and can be found about 1.0 arcsec along PA 205°. I found this second pair easier to separate than "AB", even though it is almost twice the separation. A 20cm using medium to high magnification should see each of the components. The connection of the CD is likely, though the distant pair AB-CD is presently uncertain. This pair will challenge some observers.

Δ49 (07289-3151) this magnificent pair lies near the southern Canis Major border. Both 6.4 and 7.2 magnitude stars are separated by 8.9 arcsec at PA 59°, and I saw both stars as blue and blue-white. Some change has been seen with this pair since Dunlop discovered Δ49 in 1836. John Herschel measured the separation as 15.0 arcsec, meaning the apparent distance has almost halved, while the position angle has increase 4° (1993). Spectral class of the two stars is given as B3V and B4V, with the WDS04 giving 6.34V and 6.95V for the individual magnitudes. The field is star-studded and the pair is simply bedazzling!
Hartung in AOST1&2 describes the pair in glowing terms, being;

This bright white pair accentuates a beautiful field sown profusely with stars, many of which form marked curvilinear patterns. The angle is so far fixed but the separation seems to be diminishing slowly, and if these stars in orbit the period must be very long.

Looking at the proper motions the motion in declination is A: +6″ B: +7″ per century, but the proper motion is right ascension is nearly double (-9 arcsec per century compared to -17 arc seconds for the companion.) This result means that either the orbital motion is edgewise to the line-of-site or that the proper motions are moving in similar directions. It is probable that this is an optical pair but the proof will not be known for centuries. The field also contains a 5.7 magnitude rich blue star some 23'N Another 8.5 magnitude orange star also appears some 14' (PA 242°) from Δ49. [Version 2 12/11/03]

Δ51 / Sigma (σ) Puppis (07292-4318) in my opinion is the best in this set of double stars. Located 20°S of M93, this bright pair is of 3.2 and 8.8 mag, whose components are separated by 22.2 arcsec along PA 74°. The pair is quite colourful, which I see as orange and white. Easily visible in 5cm, and little has changed in the positions since Dunlop discovered the pair in 1836.

COO 49 (07297-3209) lies 20.5' (PA 151°) from Δ49. This equal yellowish pair was discovered at the Cordoba Observatory in 1911 and was surprisingly missed by earlier double star observers. Listed as 9.6 magnitude, both stars are separated by 4.5 arcsec along PA 40°. Except for a slight 0.2″ increase in separation little has changed. The proper motions of the two are similar so they may be gravitationally associated. Tycho give the deemed secondary as the brighter star at 9.50V with the secondary being 9.63V - though visually I could not perceive the difference. This a nice pair that can be seen in 10.5cm and probably with 7.5cm.

Δ50 (07294(-3149??)) the listing of Dunlop 50 has no Declination, but Dunlop gives the star the visual identification of 146 Argûs. An assumed precessed position based on Δ49 are 07h 29m 26s (-31° 49'??) and this would be 2.4'W of No. 49. However no star appears anywhere near here.
The only clue is that the pair is separated by 2 arcsec and the magnitudes are5 and 8 which Dunlop describes asVery close double star. I looked through the entire declinations of he constellation of Argûs between -10° and -60° and between 07h 20m and 07 40m and found no candidates except RST 2482 that match this combination of clues. (Another is HJ 3982 (See Below), but this pair is too wide at 38.2 arcsec.)

RST 2482 (07299-2301) is 3.8° of Δ49 and 34'E of the Puppis border with Canis Major. The pairs position is identified simply as it forms a flat triangle (some 39' across in RA and 10' in Declination) with the other two 5.7 and 5.9 magnitude stars to the west. Within a moderately starry field, this surprisingly bright and pleasant pair can be clearly separated in 15cm using moderate magnification but is much easier in 20cm. (127x)- with the main problem being the sizeable Δm of 4.8 magnitudes.
It was R.T. Rossiter discovered the pair 1935, and for something this bright it is amazing that it was not discovered earlier. Visual magnitudes are given as 4.9 and 10.7 whose present separation is 3.0 arcsec along the north-south position angle of 180°. Unfortunately, the Hipparcos never was able to resolve the two because of the inherent problems of pairs in this resolution range of the interferometric system on the satellite. This places RST 2482 within the USNOs Neglected Southern Pairs list - thus awaiting some future measures.
Since discovery, the pair has changed very little, so attachment remains uncertain. The WDS gives the last measure as 1967, and in 1992 I thought I saw little with the last value. Spectral class is given as A5Ib which partly matches the yellowish colour reported in my double star notes. The big question is; Was Dunlop able to see these stars in his 9-inch speculum mirrored telescope? Based on the similar pairs Dunlop observed, I.e. Δ54 (3 arcsec, 6th / 9th mag.), it is just possible this could be seen. In all I think RST 2482 is likely Δ50.

HJ 3982 / p Pup / ADS 6205 (07354-2822) lies 2.6° (PA 70°) from η CMa. In a moderately starry field, this lovely wide pair of 4.6 and 9.1 magnitude is separated by 38.4 arcsec along PA 151°. HJ 3982 is easily visible in 7.5cm and is quite impressive using low magnification in 20cm. The field also contains an obvious yellow 7.4 magnitude star some 9'SW. Measures have changed little since discovery and it remains uncertain if the two are attached. Note: This is an unlikely candidate for Δ50. (*See Above)

HJ 4000 (07423-5840) is a challenge for apertures around 10cm to 15cm, and easy for anything above this. Located 44'NW R79, this 7.1 and 10.2 magnitude pair is easy to find as there is another 6.4 mag. blue star only 2.7' NNW (PA 150°). Close inspection finds that the other star is the double that takes some care to split. The problem is here is there is a moderate Δm of 2.6 mag. for the 1.4 arcsec separation. Colours are white but were uncertain because of the faintness of the comes. HJ 4000 is showing slow direct motion from Herschels angular measure in 1836 of 230° to its present 249° but the separation has remained fixed. As the proper motions in RA and Dec are almost fixed but both are at least very similar, so it is likely they are attached. Spectral Class for the primary is A1IV. Nice.

Δ55 (07442-5027) is a bright and wide yellow / yellowish pair in a fairly starry field that lies in southern Puppis near the border with Carina. It can be found 3.2°NW along (PA 322°) from Chi (χ) Carinae or 5.2°SW (PA 231°) from the gloriously bright multiple star Gamma (γ) Velorum (Δ65). When Dunlop discovered this pair, and before the grand constellation of Argo was divided into its more manageable part, the naked-eye star it was simply known as 209 Argûs. Given as 6.6v and 7.6v (6.64V and 7.55V) magnitude, the current position angle of 133° has changed very little since found by Dunlop in 1826, but the separation has slowly decreased from about 60 to 51.9 arcsec. Spectral classes for both Main Sequence stars are listed as F8 and G0 - corresponding well to the observed colours. It is likely that this pair is attached as both stars show similar proper motion. Δ55 is highly suitable pair even for the smallest of apertures.


He2-5 / Sa2-17 / ESO 209-1 / PK 264-18.1 / PK 264-12.1 / PNG 264.4-12.7(07473-5115) is a bright but very small planetary nebula in a moderately spartan field within nearby Carina, and is 55'SE (PA 145°) from the wide pair Δ55 - useful here as the field star to find the PNe. He2-5 is 3.0 arcsec across and is listed as 12.3p magnitude. It is easily visible in a 15cm especially I one is using an O-III filter by flicking it across the field.

HJ 4002 (07451-5017) lies in the same field as Δ55 and merely 13.4'NE (PA 40°) away. The magnitudes are 7.5 and 11.5 with the separation being 19.5 arc seconds along PA 91°. John Herschel when discovered the pair lists the separation as 18.0 arcsec and the PA as 87°, but looking at the slow changes both these values seem questionable, and likely this reason that it was deleted in the Index of Double Stars (IDS) in 1961. The good measures, however, between 1913 and 1933 looks like it changed very little, I saw the pair as yellowish and possibly white. Knowledge of the true attachment of the two stars is presently unknown. This is an easy pair in 7.5cm aperture.

Δ56 (07471-4130) is 3.4° SW of ζ Puppis and half-way between Δ51 σ Puppis) and ζ Pup. Magnitudes are 6.9 and 7.7 for this bluish-white duo which are separated by 49.6 arcsec along PA 177°. These stars are certainly an optical pair, but the field is quite nice. 7'E is a 9th mag orange star making a nice contrast with all the blue stars in the field. Also note the star in one of the wide 10th mag pairs some 8'N of the main star. This bottom star, 8'NNW of Δ56 is the variable RR Pup (07469-4122), which is an Algol-type eclipsing variable. The light-curve changes between 10.34V and 11.37V mag in the period of 6.4296338 days. Duration of the primary eclipse is 0.83585 days.

R 79 (07472-5905) is a wide and easy pair of 9.0 and 9.8 (8.95 and 9.84V) magnitude that was discovered by Russell on the late evening of the 10th July 1880. Position angle is fixed at 120° though the 32.6 arcsec separation (1991) has decrease from Russell's measure of 35.8 arcsec (PA 299.8°) in 1880. According to the WDS01, the position angle has changed from 300° to 120° between 1880 and 1991 - this might seem significant except that the angle is out by exactly 180°. Russells estimated the brightnesses as 9th and 9 1/2th quite close to the more exact magnitudes today. R 79 lies 1.2°W of the nebulae IC 2220 being near the centre of Carina and 4.6°W of Epsilon (υ) Carinae / Avior. Both stars share similar common proper motions and are likely attached. To me this pair looks white and yellowish in a moderately starry field. An interesting pair to look after observing the nebulosity of IC 2220. Another pair to look for is HJ 4000, some 44'NW.

HJ 4018 (07522-5937) is another triple that is fainter than HJ 4084 mentioned above that was discovered and first measured by John Herschel in 1837. About 1.3°NNW from the centre of NGC 2516, the triple lies within a field with two other similar coloured stars of near equal brightness layed out in a roughly flat triangle where HJ 4018 is the apex. HJ 4018s white primary star is given as 7.5 magnitude with a moderately close 9.7 magnitude companion, joined with another wider 11th magnitude companion. The inner pair is HJ 4018AB, separated by 5.1 arcsec along PA 327° This is visible in 15cm, and possibly in a well-aligned 7.5cm to 10.5cm telescope. Outer pair HJ 4018AC is much easier, as 10.91 mag. star has the separation is 64 arcsec along PA 259°. Proper motions suggest it is unlikely any of the stars are associated. Star A shows it is an Ap star with Silicon (Si) lines in its spectrum.
A nice southern pair.

Δ59 (07592-4950) lies in the far south of Puppis near the Carina border. It can be found 3.2°SW of the multiple star Gamma Velorum (Δ65). This pair contain two equal blue-white stars 6.3 mag. Separated is 16.4 arcsec at PA 47°, and little has changed since Dunlop discovered the pair in 1836. It is uncertain if the two stars are associated, though I suspected the equal proper motions of the stars makes this more than likely. The field is densely populated with 11th and 12th mag stars. At 11'SE is a collection of 12th magnitude stars that look like a small open cluster (which it is not).
The field also contains a deep red variable star NR Pup (07596-5009) some 10'S. The magnitude at maximum is 13.5, which is suspected to drop below 16th. NR Pup is likely another Mira variable but at present the period and details of variability are not known.

Southern Astronomical Delights”
© (2009)
10 Mar 2009