RA : 08h to 10h
SOUTHERN DOUBLES :Δ60 ,
HJ 4044 AB, AC ,
HJ 4048 ,
HJ 4053 ,
HJ 4084 AB, BC ,
OTHER DOUBLES and VARIABLES : W UMa
Δ60 (08014-5431) is
another fine wide double which lies in Carina some
1.7oSSE of Chi (χ) Carinae.
These two blue-white jewels, being a suitable target for
small apertures, are 6.0v and 7.9v (6.10V and 7.89V)
magnitude, and are separated by some 40.3"arcsec along PA
162o. These positions have
changed little since discovery. Dunlop never made a measure
of the components other than identifying the position as
07h 57m 24s -54o 02' (1825) and
the magnitudes as 6,9. It was John Herschel who
made the first micrometrical measures in 1837. The notes in
the WDS03 states that one of the components is both a
variable and spectroscopic binary. This variable is in fact
the primary and is listed as NSV3871 in the GCVS4. Looking
at the small proper motions it is difficult to tell if the
stars are connected. Δ60A is listed as HIP 39225 /
SAO 235686 / PPM 336582 as a B2 IV-V spectral class star.
From the proper motion of 2.47±0.50mas the distance
is about 404pc. Δ60 B has an ill-defined proper
motion and is unusually not registered in the Hipparchos
catalogue. The field contains a number of brightish stars,
with a blue 5.4 magnitude star some 22'N.
In all this is a pair that is easy to find and worthy to look for.
HJ 4044 AB, AC (08025-5502) is
a triple star that lies in the next southern field 33'SSE
(163o) from Δ60. This star
field contains three richly orange coloured stars all
formed into an isosceles triangle that points west - HJ
4044 being the most northerly of the trio. Another two blue
stars also lie about 27'S of the pair.
HJ 4044AB is listed in the WDS as 8.7 and 10.3, whose separation is 29.1"arcsec along PA 213o Between 1892 and 1994, the PA has shown prograde motion, decreasing from 221o to 213o, while the separation has increased from 28.7"arcsec to 29.1"arcsec. HJ 4044 AC often appears as the only main double in some catalogue and books. The companion 'C' in comparison is certainly the fainter than 'B'. 'AC' itself is separated by 31.4"arcsec along PA 199o that since 1913 has increased by 0.4"arcsec and decreasing by 3o in PA.
All stars have very similar common proper motions and no doubt they are all related. HJ 4044 A to me looks like a deep orange star that matches to given K0/1III spectral class, while the fainter companions to me seemed yellowish or white. This will be an interesting system to watch in the future.
Δ61 (08068-2707) appears 2.8oS of Rho (ρ) Puppis (15 Pup). The field of Δ61 has many bright stars, whose centre, including the double, appears like a 15' sized arrowhead. This pair is slightly uneven in brightness of 7.1 and 9.0v magnitud, being separated by 70.7" along PA 35o. The pair is contrasting, with the primary being strong blue and the companion a startling reddish-orange. The only measure made for this pair was in 1920, and it has already be ascertained as just chance alignment. The companion star is also double, being the pair B148. Discovered by van der Bos in 1926, who provided the only measure to date, who found the 12.5 mag companion separated by 2.4" at PA 135o. In 20cm, the magnitude difference seemed to make it more difficult than I expected observers could see this pair in 15cm, and maybe 10.5cm in good conditions.
Δ63 (08097-4238)is last pair listed by Dunlop pairs within Puppis, being located 2.8oSE of Zeta (ζ) Puppis. This bright pair lies in a very starry field whose components are 6.6 and 7.8 mag, The pair is easily visible in 7.5cm, separated by 5.6" along near east PA 81o. Hartung's "Astronomical Objects for Southern Telescopes" (AOST1 and 2) describes the pair as;
This elegant white, unequal pair in a very fine starry field with a pronounced curved line of stars coming in south and ending in a small wide pair 3' east and should shown well in 10.5cm.
This statement is a bit confusing, as I found that the magnitude difference was as listed. As for the curved line of stars, I thought this made the field quite attractive, but I though the telescopic asterism was more "arrow-like" - at least this is what my observing notes say. This is an nice pair worthy of a glance.
HJ 4048 (08087-4211) lies in the next northern field from Δ63 This John Herschel 9.5v and 9.8v magnitude pair is presently separated by 7.9" at PA 210o. Both stars I saw as white. Little change has been seen in the positions since H.C. Russell again measured HJ 4048 in 1879. If the pair is associated, the period is certainly long.
HJ 4053 (08082-6105) is another Herschel pair that can be found by moving 1.3oESE of NGC 2516. This is a nice bright yellow and deep-yellow orange pair easily visible for all small telescopes. Separation is 19.3"arcsec aligned southwest along PA 319o, with little changing since discovery. A really brilliant southern pair that is sadly missed in many astronomical observational texts.
HJ 4084 (08179-5910) is a nice
triple in a moderately spartan field 41'NW (PA
302o) from Epsilon Carinae.
Suitable for small telescopes, HJ 4084 AB is a wide
6.50 / 9.81 magnitude yellowish and white pair separated by
42.4"arcsec at PA 150o. Closer
inspection finds that the ‘B’ component is the
pair HJ 4084 BC appearing a near equal 9.8 and 9.9
(9.81 and 9.88V) magnitude. Split with care in 7.5cm, and
easy in 10.5cm, this dual white pair is separated by
3.1"arcsec along PA 88o. Another
faintly yellow 10.4 magnitude “D” star lies
1.3' (81"arcsec) PA 234o away,
making a right-angled triangle, though this is not listed
with the other stars.
John Herschel first found this triple in 1836, who estimated the respective positions of AB 60"arcsec and 4.0"arcsec. It was H.C. Russell who made the first true measure of the AB pair under “bad definition” on the 23rd April 1879. Innes later measured both these stars again in 1917 showing little change in the relative positions, giving the placements as; AB 43.8" 155o and BC 3.1" 87o. The latest WDS02 gives the Tycho-2 positions, as first stated above.
More confusing is that the Guide Star Catalog (GSC) shows all the stars, except the “A” component is two stars and the “BC” stars are single! In the “A1” is given as GSC8579:2691 and “A2” as GSC 8579:2677, but both have the same 6.5 magnitude and the spectrum as F8, with the separation as 2.0"arcsec at PA 11o. This had me fooled at first, but it is now likely just a simple duplication error.
This is an unusual triple. The brighter star is the single component, with the pair being the fainter stars - making HJ 4084 among few systems having this property. Normally we would find the reverse of this situation in triples and multiples, leading to suspicion that the placement of the A-BC system is merely optical. Examination of the association of these three stars suggests the AB stars are not connected. The BC components, however, remain uncertain - but they are probably joined. This is further confused with the larger Tycho 15.40mas parallax, but this is well within the errors of the observations. Using the less-than precise Tycho-2 1991 data, the parallax and proper motions are as follows;
HJ 4084 System
If these proper motions are to continue then the A-BC will
close. (See Figure xx) Based on the values within the
Table, by 2330AD all four star will form a roughly straight
line along PA 94o with all
separations being a little less than half of today’s
distances. The AC stars will approach each other but will
be no closer than c.20"arcsec (2270AD), while the
“AD” closest approach will be 13.7"arcsec along
PA 40o in 2490AD. (Arrow near
2500AD mark for both ‘A’ and
Overall, this is an attractive group of stars worth looking for if you are near the False Cross.
Coloured Pair (08182-6019)
This lies only some 1oSW from
Epsilon Carinae. These two bright stars I found while
sweeping the general area with 7x50 binoculars. Not list as
any WDS pair, this blue-bluish and orange pair is
remarkable for its colour contrast. At 7.3 and 7.8
magnitude (7.29 and 7.75V), with the two stars separated by
2.2' at the near eastern PA of
This one is almost a worthy of a Dunlop-like pair.
I 194 (08190-6012) is a yellow duo in the same field as the “Coloured Pair” mentioned above by about 10'NE. Another 9.4 magnitude star lies 1.9'N of the I 194, making certain identification a little easier. Magnitudes are 8.8 and 9.8, respectively, while the PA is 129o and separated by 1.5"arcsec. Interestingly, the WDS gives fainter magnitudes of 9.18 and 10.16. Clearly divided in 20cm at 333x, this dainty pair is worth seeking out. Since Innes discovered this pair in 1897, the stars have been slowly closing, while the prograde motion has reduced by some 5o. Looking at the proper motions, these two are probably connected.
Epsilon (ε) Carinae / NSV4058 / HIP 41037 / PPM 336856 / SAO 235932 / HD 71129 (08225-5931) is a suspected eclipsing binary system whose variations are thought to change between 1.64V and 1.82V in an unknownperiod. The combined spectral class of the two unresolvable stars is K3-III+B2V, merged to give the light yellow colour of the star to the naked-eye. Hipparcos and Tycho both gives the B-V as 1.195±0.003, while the Hiparcos parallax is 5.16±0.49 giving the distance as 194±18.5pc or 632±60.6 ly.
HJ 4096 (08234-6100) & HJ 4097 (08234-6059) are two pairs in close proximity. Normally I would not mention these two pairs because they are quite though easy to resolve. The position of this and the galaxy ESO 124-15 can be quickly found by moving directly 1.5o due south from Epsilon Carinae / Avior, or alternatively, moving 3.1o due east of NGC 2516. HJ 4096 stars are 10.0 and 12.5 magnitude separated by a wide 15.2"arcsec along PA 88o. HJ 4097 stars are 10.0 and 11.4 and a separated by a smaller 11.0"arcsec along PA 8o. Since discovery HJ4096 has only rapidly increased in separation (c.5.2"arcsec), while HJ 4097 has decreased by 1.2"arcsec and has shown some direct PA motion. For a fleeting moment I thought I was looking at an obviously fainter but mini-version of the famous northern double-double Epsilon Lyrae near the first-magnitude star Vega. These are not the most enchanting pair I have looked at, but seeing two pairs together like this is a bit more unusual.
ESO 124-15 / PGC 23550 (08237-6053) is 7.6'N from HJ4096/ HJ4097’s position a the 14.3p magnitude galaxy in the same field. This should be visible in telescopes in dark skies above 20cm or 25cm. Data on this object gives the size as 1.7'x0.8', but expect to see only between half to one-third this size in the telescope. ESO 124-15 is also deemed a SB(s)bc barred spiral galaxy.
R 84 (08246-5909) is a near equal
yellow duo is presently separated by 8.9"arcsec along PA
33o (1991) It can be very easily
found without much trouble 27'NE of Epsilon Carinae. The
pair is readily identifiable, as another yellowish star
lays 1.5oNNE. H.C. Russel
discovered this pair and provided the first measures at
around 10pm on the 9th May 1881 - being 7.71"arcsec at PA
213.8o. Magnitudes by Russell
were stated as both 10th, and subsequent observers adopted
11th. The latest WDS02 gives the magnitudes as 10.46 and
10.53. In the last hundred-odd years the two stars have
slowly widened while the PA has remained much the same. It
is still uncertain if the stars are associated, as the
proper motion in RA disagree and the proper motion is
declination are opposite. Yet the Tycho parallaxes agree
quite well, being ‘A’ 121.60±31.50mas
and ‘B’ 135.80±29.40mas.If these are
true, then the distance of ‘A’ is
8.22±2.28pc (26.8ly) and ‘B’
7.36±1.67pc (24.0ly.) If they are joined then the
true separation is presently about 70AU.
Another 40"arcsec ESE (PA 118o) is a fainter 12th magnitude star. In all this field is very attractive under high magnification. Glorious, in a faint star-filled field.
A pm RA 077.72 +32.50 Dec -72.20 +37.70
B pm RA 125.30 +28.70 Dec +48.30 +31.70
I 801 (08264-5926) is a more difficult pair than R 84 (above) but lies in the same eyepiece field. Some 22'SE of R 84, the field contains eight 9th to 10th magnitude stars roughly organised in an arrow-like shape. I 805 is the brightest of all these stars, being 8.6 magnitude, and when split, 8.82 and 10.33 magnitude. The companion appears as a fainter star the SW. Little has changed in the relative positions since R.T.A. Innes discovered the pair in 1910, though Innes measure oddly found the separation as 0.8"arcsec. It was just seen in 20cm at 333x, and I estimate that 15cm is about the minimum aperture to clearly split the duo. The colours I saw as yellowish and white. Common proper motion suggest the stars are connected.
FIN 392 (08265-5912) lies 13.6'N of I 801. I looked at this pair in 20cm, because it is near I 801, but I could not split these two faint stars in the early 1990's. The WDS November 02 gives the present separation as 0.8"arcsec along PA 171o, and the fainter magnitudes of 11.24 and 11.11 - suggesting the discoverer’s estimating that the primary was bright was wrong. The positions really have changed little since it was discovered by Finsen in 1937. Data on this pair is still poor. If the present widening is true the pair could be seen in 20cm with care.
V Car (08287-6007) is a Cepheid variable varying between 7.08V and 7.82V over a period of 6.69668 days. Like most Cepheid it appears just like a yellow star, and this reflects the mean changes seen in the spectral type, which the GVSC5 gives as between F6 and G2 Ib-II. he rise from the minimum to maximum takes about 30% of the period, equal to almost exactly two (2) days (2.009 days, in fact). This augers well for observations at the same time each night over one whole week, and would be an interesting project for a new comer to see a real Cepheid in action. (JDE 2437454.023) A 7.8v magnitude comparison star appear 6.7' WNW which fortunately has a similar spectral class.
V343 Car (08290-5948) is a red Mira type variable that varies between 13.3p and 17.5 in an unknown period. Positioned 24'N of V Carinae, the general field chart shows its overall position in case you see it. The location can be further identified by another 11.8 magnitude star only 44"arcsec to the northwest. I could find little in the literature about this star.
X Car (08313-5913) is an EB/KE eclipsing binary showing a smallish magnitude range. It can be located 1.1o E of Epsilon Carinae and lies on the westward line passing through I 801 (above) Magnitude change between 7.90V and 8.65V in a period of 1.0826310 days or 01d 01h 59m59.3 s from the epoch of 18th November 1937 (JDE 2428857.146.) Both stars are classed as A0V P=1.0926310 in ACTA (1980).
ESO 124-19 (08317-5947) lies 33'S of X Car and I only mention these for completion. These faint two are both 14.8p magnitude separated east-west by 31"arcsec. At least 30cm is required to see them, and they look like to small wisps of cloudy nebulosity, being about 30"x25"arcsec and 16"arcsec across, respectively. Looking at the STScI image, ESO 124-18 is a barred spiral with some ring structure, while ESO 124-49 looks as it is probably a companion spiral galaxy of some sort. The RV’s are almost the same, with the mean of +6 374kms-1, so they must be associated.
d Velorum / HJ 4133 (08444-4239) is a wide yellow pair with a substantial difference in brightness. Given magnitudes, since discovery in 1835, the separation has slowly decreased from 47.2" to 44.8"arc sec while the PA has increased from 61o to 63o. Spectral class of the primary is G5III. Judging from the proper motions, this is certainly an optical pair.
I 815 (08447-4117) is a multiple
whose four components are listed as;
H Vel / R 87 (08563-5243)
is an interesting bright blue and white pair in Vela some
2.8oNE of Delta Velorum or
alternatively 2.4oE of the
naked-eye open cluster IC 2391. Given as 4.67 and 7.92
magnitude, these stars are just visible in 7.5cm and easy
in 15cm. (2002) Since discovery on 4th April 1881
(1881.256) both the PA and separation have decreased by
335o in PA and by 0.9"arcsec to
2.5"arcsec. No doubt the stars are associated and it is
extraordinary that both J. Dunlop and J. Herschel had
missed this obvious pair. It is possible the orbital motion
of the two stars were unresolvable at the time.
Russell saw these two stars as yellow and bluish, while oddly AOST sees pale yellow and yellow, which to me is the reverse in how it appears in the sky. However, there are far more severe problems with Russell's data. For example, he gives the PA as 249.5o and the distance of 3.17"arcsec. Furthermore the magnitudes of the two components are 6th and 9th, and are significantly different than WDS01's magnitudes. None of these values seem to match this pair, though the 1880 positions of 08h 53m -52o 16' are correct for this star. I searched for other pair that might match R87 in case there is two possibilities that exist.
The component R87 A is a known spectroscopic binary with a period of almost exactly twenty-two hours or 0.917 days.
AOST2 says that the main stars is still indeterminate regarding the binary nature of these stars because of the small proper motions of the stars, which is true, however the twenty-six measures to date shows a curve that suggests association. In the years to come this system will be interesting to watch, and perhaps some of its mysteries warrant some future investigation.
b2 Car (08570-5914)
was discovered by Dunlop in 1836 and appears in the same
field in a medium magnification eyepiece as I 318 mentioned
below. I saw the colours as blue and bluish-white. This
bright and wide pair, with magnitudes of 4.87 and 6.58, the
pair has a separation of 40"arc sec whose orientation is
along PA 76o. These last measures
being taken from the 1991 Tycho Star Catalogue and little
has changed in the positions since discovery with the PA
reducing by 1o and the Sep by
J Graham Little says of Δ74; (Southern Astronomy, "Ten O'clock High" Mar/ Apr 1994 pg.54)
This is a very wide double that, with a steady hand, can be seen through binoculars. The primary star is a bluish-white... The companion star is ... roughly the same colour (B8), but is obviously fainter... [and] looks best with low magnification, when the stars are kept close together.
Primary star Δ74 A / HIP 43937 / SAO236436 is
of B2IV-V spectral type and is the Beta Cepheid variable
star V376 Car. Originally this star was NSV04328
identifying the star HR3582 as the variable, giving the
magnitude variance as about 0.10. Observations of the
variations find a 0.05 magnitude difference over a period
of 0.208 days (4hr 59.5m)
In the Δm catalogue of the WDS the difference was observed by Pickering in 1912 as 1.67 magnitudes and later, by A. Wallenquist in 1948 using a wedge photometer and finding a delta-m of 1.34. The latest photometric observations give the difference of 1.71 magnitudes. If the HIP parallax of 5.25±0.46mas is correct, then the distance of the system is about 190±15pc or 620±50ly. If the stars are truly connected, the period must be very long.
I 318 / b1 Car (08594-5905) is another wide pair with a considerable difference in magnitude lying some 21'ENE (PA65o) of Δ74.Both stars are separated by The WDS01 shows the PA had increased by 7o and reduced in separation by 2.7" between 1900 and 1914. I saw the colours as yellow and white. It is unknown if these two are associated as no proper motion information has been collected. This field is has numerous stars in it, and has two 8th magnitude stars - the yellowish 8.3 mag HIP 44158 (3.1'NNE) and the white 7.8 magnitude HIP 44055 (14'SW). This last star being roughly midway between b1 and b2 Carinae. This is also a nice field.
HJ 4171 (09000-6444) (Vol) lies due 1.0oW of Miaplacidus and is yet another faint pair. Quoted magnitudes are 10.1 and 11.1 as first measured by Innes in 1918. Contained in a starry field, the pair is separation is 14.6" at PA of 237o. and is visible in 7.5cm. Although separation of the pair is easy for small apertures, the magnitude of the stars may require 10.5cm. to see it clearly in less than perfect skies.
GP Vel / Vel X-1 / HD 77581
(09021-4033) is one truly remarkable astronomical object
which lies 3.0oNW of NGC 2792. At
first glance it appears just to be another eclipsing binary
with small fluctuations in brightness, but it has proved to
be much more complicate object, as one of the components is
an example of an Alpha Cygni (ACYG) variable and being also
the X-ray source Vel X-1. (This should not to be confused
with the radio source Vel X nor the Vela Pulsar associated
with the Vela Supernova Remnant. (VSR)) It is also an
spectroscopic binary associated with HD 77581. Vela X-1's
optical component is also being known as EQ Vel.
GP Vel itself varies between 6.79 and 6.99 in the period of 8.9647 days, based on the rough epoch 2444275.20. The primary is extremely luminous being of spectral class B0.5 Ia+ and shows extremely violet-shifted Hα absorption lines with a velocity of 400kms-1. The companion star is much smaller in mass whose influence is significant enough to cause gas to stream between the two stars. We know this because the spectra of the primary star has several superimposed bright emission lines characteristic of a gas stream. What is unusual about this system is the longer than expected period compared to other sources, but if the orbit eccentricity is significant, this may only be contrived effect - the conclusion that Hutchings (1974) and Bessell (1975) first suggested. Based on the observed radial velocity of the components (~+300 kms-1 and ~+20kms-1) the mass of the companion is between 1.5 M and 2.0 M, suggesting a neutron star. Its size is exactly in between what would be expected for either a white dwarf or black hole.
GP Vel is one of the closest of the eclipsing X-ray sources known whose distance maybe anywhere between 1.0kpc and 1.6kpc.
References for Vel X-1 / GP Velorum
1. Bessell, M.S., Astroph. J., 195, L113 (1975)
2. Heintz, W.D., Double Stars p.162. (1978) Pub. D.Reidel Pub.
3. Hutchings, J.B., Astroph. J, 180, 151 (1974)
E Carinae/ V345 Car / SAO 256583 (09057-7032) is a Gamma Cassiopeia (GCAS) type variable. This blue-white 4.67 mag star lies 24.6'SW (0.97o) of Miaplacidus, and is one of the brightest of its class. Most of these types of stars often vary by up to 1.5 magnitudes that normally appear without any known periodicity. They are peculiar to the spectral class of sub-giants B-type (B0 III-B3 V), and are exhibited in about 0.4% of all known variable stars. Known as shell stars, they are subject to temporary fades of one to three magnitudes. The variation of this one is only 0.11 magnitudes that vary between 4.67 and 4.78. V348 Carinae has the spectral class of B2 Vne.
Lambda (λ) Velorum / See
109 / HIP 44816 / PPM313999 / SAO 220878 / HD 78647
(09080-4326) is commonly named Al Suhail or just Suhail,
and can be usefully employed to find NGC 2792, and appears
in the north-western part of Vela. As the 55th brightest
star in the sky, this orange star is 2.14v magnitude and is
an example of the rare Lc-type irregular variable stars
-one of only forty-five known. Sharing kinship with Taurus'
first magitude star Aldebaran, it holds the honour of being
the second brightest example of its class. Brightness
fluctuations have been observed to diverge by some 0.08
magnitudes. The Lc variables are significant because they
sometimes show complete absence of periodicity in their
light-curves where as other show at least some. A few
examples show the brightness changes that are slow and
continuous, but several have changed quite abruptly. Most
display spectral types between K and S and are exactly the
same of the more common Lb-type irregular variables except
for being supergiants. Vel is classed as K4 Ib-II, upgraded
from the K5 data. Lambda Velorum shares kinship with the
first magnitude Alpha Tauri, Aldebaran, which is an Lb-type
that varies roughly by only about 0.2 magnitudes. However,
although Aldebaran is of similar spectral type, K5, it is
just a giant star of luminosity class III. Other bright Lc
variables include Beta (β) Gruis, Omicron 1
(ο1) Canis Majoris, Psi
(ψ) Aurigae and Eta (η) Aurigae.
The orangery-redness of the star is shown with the B-V is 1.665±0.013 (HIP) and 1.685±0.006 (Tycho) Hipparcos found the parallax of 5.69±0.53 giving the distance of 177±16.5pc. Proper motions are in RA -23.31±0.50 and 14.28±0.41, and this is similar to the PPM and Tycho data.
Suhail is also the double star SEE 109, however, it is a very difficult object to resolve as the magnitude difference is 12.6. Since discovered in 1897, no change has been observed in the position angle or separation, which is given as 18.2" arcsec along PA 137o.
TX Vel (09130-5449) is an
irregular variable star that varies between 10.0 and 13.0.
Placed a mere 10.4'W from the planetary He2-22 (PA
287o), I saw the magnitude as 10.5, based on two
or three nearby field stars of known magnitude. Little is
known about this star, except that it is a yellow G5
supergiant, though I did not see any colour in 30cm.
Two pairs are found in the southern part of the same field, but both could be clearly separated using a high magnification.
Beta (β) Carinae /
MIAPLACIDUS (09132-6943) is one of the brighter
stars of the southern skies, and can be found about halfway
between the Southern Cross and Canopus. From Sydney it is a
circumpolar star, and although it is today placed in the
modern day constellation of Carina, it was once, prior to
the mid-17th Century, lay within the super-constellation of
Argo Navis. Later, Argo gained a new
sub-constellation called Robur Carolinum. Created by
Edmond Halley and officially published in 1679, Robur was
made to commemorate the place known as the Royal Oak. This
location protected the defeated Charles II, after his army
was routed by Oliver Cromwell at the Battle of Worcester in
September 1651. La Caille complained bitterly about
Halley's addition because it destroyed most of the
prominent stars in the Ship. (Halley, however, didn't
complain. It ensured that he received his Masters Degrees
by royal proclamation!) From about 1720, popularity for the
constellation of 'The Oak' was slowly reclaimed back into
Argo Navis. Its common usage probably ended in 1800 with
Johann Elert Bode's star atlas 'Uranographica'. From
then, like many others, Robur simply fell into antiquity as
an obscure constellation. American astronomer Benjamin
Apthorp Gould in 1879 subdivided this part of Argo Navis
into smaller constellations, and Miaplacidus became part of
Carina. This change was permanently adopted by the IAU in
Once known as Alpha Roburis, Miaplacidus was supposed to have been derived from the Arabic Mi'ak or 'waters', while the Latin 'placidus' was added much later. I assume that from Arabia, the Chaldeans would have seen this bright star in Summer glimmering close to the southern horizon of the Indian Ocean. Today, however, Miaplacidus is fully translated to mean 'placid waters' - appropriate because the star lies in the bilge of the ship!
This white star culminates annually at 9 pm on the 26th March. In order of brightness, at 1.674v magnitude, makes 28th among the naked-eye stars. Distance is given as 26.1 pc. or 85 ly., although the latest information by Hipparcos gives the much further distance of 34.09pc or 111.2 ly. The spectrum of this giant star was for many years given as A0 III, though it has recently been downgraded to an A2 IV, indicating a surface temperature of 8 700K. Measurements suggest an absolute magnitude of -0.4, so the true luminosity is about sixty times brighter than the Sun. Miaplacidus has been shown from the radial velocity that it is approaching us at a pedestrian 5kms-1. This is similar to the first measure in 1927, from the famous southern station of Harvard University in Chile. By 1970, careful inspection of the broadening of the spectral lines showed that the rotational (V.sin i.) velocity is c.145kms-1. Using general stellar evolution theory, the rotation of the star would have a 'stellar day' possibly as long as c.60 hours (or 2.5 days) for its nine million kilometre girth. Proper motion measures is 36.7" per 100 yr.-1 towards the constellation of Volans, which it will crawl into about the year 9 800 AD. Also in the future it will become the southern pole star in 6 200 AD, approaching by some 5° 42'. It is interesting to note that about the same time, Alpha and Beta Centauri will also be making their closest approach of 23'. Today, it stands as a lonely sentinel on the edges of the magnificent southern Milky Way.
HJ4164 (09135-6455) is in the same field as NGC 2808, some 9.5' ESE, is this John Herschel pair first measured by Russell in 1879. The stars are 10.0 and 10.6 mag, separated by 16.4" along position angle 64o.
HU 1457 (09144-5500) is the first, which was discovered by Hussey in 1913. Both these white stars are of near equal magnitude, which is stated as 10.3 and 10.8, respectively. Separated by 1.3"arc sec at PA 260o. Since the last measure in 1957, the position angle has reduced by 10o since discovery. The proper motions suggest that the two are likely physically associated.
I 11 (09152-4533) is a wonderful close and near equal brightness pair some 10.7'WSW (PA 244o) from the planetary known as Pb5 or He2-24, and hence, is useful for finding this PNe. I saw this pretty bluish-white / white pair being resolved with some difficulty using the 20cm (C8) at 234X. (AOST2 describes I 11 as having "...no perceivable colour difference.") My estimate for the Δm was 0.6, and this is quite comparable with the WDS 2001 that gives 0.8 from the 6.7 and 7.5 listed magnitudes. AOST2 claims it can be split in 15cm, though at present time, it would have to be the best observing conditions to do so, as the pair's distance is slowly diminishing. I would consider 20cm is closer to the mark but using telescopes greater than 30cm will become much easier. I 11 was first discovered by Innes in 1895 and was first measured by R.P. Sellors in early 1896. Since this time the PA has increased (direct motion) from 271o to 292o - nearly 30o while the separation has decreased by about 0.15 arcsec. (2002) The spectral class of the duo is B8V. This system is without doubt a binary system of a moderately long period and will be worth watching in the coming decades. A nice pair.
LW Car (09157-6921) is some 7'E is the faint galactic RR Lyrae variable. I only mention it, as photographers can easily detect it it. LW Car's magnitude varies between 14.5 and 15.5 and has a poorly estimated period.
R 107 (09165-5824) was discovered by H.C. Russell , sometime in 1881, as he unfortunately gives no specific date for this object's first observation. He estimated separation as 8", and said the magnitudes were 9th and 10th. Of the three observations between 1882 and 1917, separation has remained at 9.5" at PA 285o. Observers can find it near a bluish 6.1 mag star in Carina (SAO 236772; Spectra B5), some 10'S and 39' due west of NGC 2867. Stated magnitudes are 9.5 and 11.2, making an attractive contrast, and the pair is in a rather pretty field of moderately bright stars. It is easily visible in 7.5cm, though I could not distinguish any colour. This was the same in both the 20cm (C-8) and 10.5cm refractor.
FIN 133 (09166-5506) is the second and lies 19'SE. Using the triple star mentioned in the text with He2-22, continuing along the same direction until the solitary 10th magnitude is found. This is the pair. Discovered by Finsen in 1930, this pair is almost identical to HU 1457. Magnitudes are given as 10.3 and 10.4, and are separated by 1.7"arc sec. at PA 273o. Again the proper motions suggest that the stars are associated. In all, both stars can be separated in 15cm, with care, and easily in 20cm.
RMK 10 (09179-6948) is a white and yellowish pair of magnitude 7.8 and 8.1 magnitude, first discovered by Rumker at Parramatta. The pair lies 24'E of 2nd magnitude Beta Carinae. Of the nine measures, last in 1958, the positions remain 10.5" and PA 18o. No significant change has been observed with this pair. It is possible that it is a true binary, though its period is probably very long. In the same field as RMK 10, is the pair R110.
R110 (09182-6941), that H.C. Russell first found using the 29cm.(11.5") at Sydney Observatory on 21st May 1881. Russell's measures revealed a PA of 26.6o and a separation of 11.1". The magnitude of the two stars is 10 and 11. Little has changed with the pair, and is likely to be just an optical system.
R111 (09208-5716) is found in a starry field some 55'SWW of IC2488 (See last month) or exactly 1.0o of NGC 2867. Within a small horseshoe-shaped asterism, R111 lies next to another field 9.8 mag star to the east. Discovered by Russell at Sydney Observatory on the 5th March, 1873, with the first measure occurring on the 7th May 1880. His observations records 11th and 12th magnitude, separated by 8.52" at PA 209.1o. Later observations have determined the respective as 10.0v and 11.0v magnitudes, with only three measures since this time, with the latest being in 1948. This last observation shows an increase separation to 9.2" at position angle 213o. My estimate in 1992 suggests the separation has increased to about 11". We know few details about this pair, and glancing at the proper motions of the components, it is likely that this is a chance alignment of an optical system.
V Velorum (09223-5558) is a Cepheid variable that fluctuates between 7.19v and 7.95v magnitude over 4.370991 days, whose period is set from 30th May 1970 (JD2440736.25) at 18h UT. The rise in magnitude in the outward pulse takes about 1.3 days to reach maximum brightness. Spectrally, this sub-giant varies between F6 at maxima and F9 at minima.
Jacob 5 / JC 5 / ADS 7379 (09267-2847) was discovery in 1858 to lie 40'E of λ Pyxis and halfway towards the variable S Antliae but still within the constellation of Pyxis. Jacob 5 is the close 0.6"arcsec bluish-white coloured pair of 6.5 and 7.2 magnitude. (Burnham's Celestial Handbook, incorrectly states that the stars are 8 and 8.5 magnitude.) A 30cm telescope can probably resolve the two, using high magnifications and under good seeing. Since, the separation between the two stars has remained fixed but has PA has decreased by 40o since this time. It seems likely that this is a true binary system with several hundred years as the period. The spectrum reveals a B8 star, with the individual component spectral classes still unknown.
BRT 2548 (09281-5652) is some 6'NE from the planeary nebulae IC 2488's centre, and is placed near the cluster's edge. (Top left in Figure 4) Discovered by S.J.Barton in 1924, this faint pair is 11.0 and 12.0 magnitude, whose solitary micrometric measurement gives the separation as 3.6"arc sec at PA 174o.
RST 408 / NSV 4516
(09304-5822) appears as a naked-eye brightish red star some
35'SW of R123 (PA 235o) position. This pair is
very difficult as the magnitudes are 5.9 and 13.5
(Δm=7.6) and the two are separated by 2.3"arcsec
along position angle 98o. Since discovered and
measured by R.A. Rossiter in 1930 there has been no further
measures. Whether the companion is still in this position
some seventy-five (75) years later is anyone’s
I could not see the companion in 20cm the two times I looked at RST 408 even when I tried using an occultation bar to eliminate some of the primary’s overwhelming light. I suspect either 30cm to 40cm could see the stars elongated and under very good seeing split the duo.
Both the GVSC4 and the WDS03 Notes lists the primary as a suspected irregular variable NSV 4516 / HR 3793 (09304-5821) that changes between 5.86V and 5.94V is an uncertain period. It nature is yet to be determined.
Catalogued as HIP 46620 / PPM 338035/ SAO 237056/ HD 82536 this average 5.88 mag. star shows a B-V of +1.676 and the spectral class of M2 III. Hipparcos gives the parallax as 3.08±0.55giving the distance as 325±56pc. or 1060±195ly. It is unknown from the available information if the stars are associated.
N Vel / SAO 237067 (09312-5702) is an orange K5 III star (B-V of +1.538) that is listed in the GCSV4 as possible variable star that changes between 3.12V and 3.15V magnitude in a unknown period, but little change has been seen in recent decades. However the designation of “CST:” means this star actually shows constant light. The N Velorum designated name is also misleading, as all variables may only range between R and Z in a particular constellation. N Velorum is the Roman letter given to the star by Bayer’s original Uranometria when Carina and Vela were in the grander constellation of Argo Navis. This star locates the double star SYO 1whch is only 13.2' away. Hipparcos gives the parallax as 13.72±0.51 that calculates the true distance as 72.9±2.7pc. or 238±8ly. It is possible this might be a secular variable.
R119 (09316-5602) is another fainter pair 3'W of R120. Discovered on the same night as R122 and R120, the magnitudes of this duo are 10.6 and 11.5. Separation is a wide 17.0" at position angle 200o. These last measures were taken 1934. Little has changed since then. Faint but visible in 7.5cm.
R120 / SAO 237073 (09319-5602) is some 3'W of R122, and was discovered on the same night as R122. Russell's original measures show a separation of 9.59" at PA 34.5o Later observations of R120 show that Russell PA was out by 180o, a common problem sometimes facing double star observers. The current PA is 215o. Both are written as 10th magnitude, though later observations suggest the respective 9.2 and 10.2 mag. I saw both colours as slighly bluish. In all, R122 (and R119 and R120) are contained in a starry background and easily found some 42'ENE of the planetary NGC 2899 or 20'NNE from the planetary, Sa3-10. A 7.5cm will ind these pairs faint but certainly it would be better placed in 10cm or above.
R122 / SAO 237078 / HD 82789
(09322-5601) was discovered by H.C. Russell at Sydney
Observatory using the 17.5cm. (7.3") on the 18th March
1873. The magnitudes of this yellow and white pair are 8.4
and 10.2. Separation is 2.5" at PA
110o , and these values have
slowly been decreasing since discovery. Right now it is
uncertain if this is a physical system or an optical pair,
but if it is a true binary, the period must be more than
three hundred years. This pair will be interesting to watch
over the ensuing decades.
In all, these three pairs above are contained in a starry background, and can be easily found some 42'ENE of NGC 2899 or 20'NNE of planetary nebula SA3-10. A 10cm is required to see R119, R120, R122 clearly.
S Antliae (09323-2838) is the
brightest example of this class even though it is ignored
in the literature. S Ant lies close to Antlia's border with
Pyxis, being 2oE of yellow 4.7
magnitude Lambda (λ) Pyxis. Also, exactly halfway to
S Antliae is the 6th magnitude close pair Jacob 5. (See Above) Magnitudes vary
between 6.4 and 6.92, changing equally in both the primary
and secondary minima by the 0.5 magnitudes every 15.92
hours. (0.6484 days) The period between successive
magnitude drops have been measured as 07 hrs 46 min 50 sec.
S Antlia lies within a starry field and 20'W is two faint
7th magnitude stars that are suitable comparison. The
variable has a magnitude greater at maximum and lesser at
minimum than these stars.
In real terms, both S Ant's stars are separated by only 2.2 million kilometres, with each star having an average diameter of 2.4 million and 1.3 million kilometres, respectively. Due to this close separation, both stars are highly distorted, with mass transfer as presently observed being a real possibility. Total mass is the same as the Sun, with the individual masses dividing as 0.68 M and 0.32 M. Surface temperatures are 8 300K and 7 350K. In terms of the Sun's luminosity, the output of the components is 12 times for the primary and 2.3 times for the secondary. Present distance for S Ant is estimated to be 91pc or 300 ly.
SYO 1 (09328-5706) is a charming
blue-white and white pair lies 1.8'S of the southern Vela
border with Carina being suitably placed 13.2' ESE (PA
107o) of the 3.1 magnitude and variable star N
Velorum. The pair can be seen in 7.5cm but would be better
in anything over 15cm. An obvious 8 1/2th magnitude yellow
field star also lies 3.8'SE of the SYO 1.
Discovered probably by R.T.A. Innes before he moved to South Africa, as the first pair in the Sydney Observatory double star catalogue of 1895, it is listed in the WDS Reference file “from additional DD list.” This should not be confused with the H.C. Russell’s Second “New Double Stars” list presented to the Royal Society of N.S.W. on the 5th September 1883 that Russell later published himself. (See WebPage) SYO 1 is also the first of the pairs discovered away from the influence H.C. Russell’s earlier double star work - properly named for the Observatory ad not the individual Government Astronomer. (In 1893 Russell had long stopped his work of double stars almost twelve years earlier.)
SYO 1 itself is a 7.1 and 11.0 (7.12V and 11.06V) magnitude star that is separated by 10.7"arcsec along position angle 20o. Little has changed in the relative positions of the two stars since discovery. It is likely these two are a true pair as the motions are similar but the orbital period of this must be very long. Spectral type in the WDS03 as B6/7II/III.
R 123 (09333-5758) has a
combined magnitude of 6.1 making it a naked-eye star in
Carina. It lies 1.0o SSE of N Velorum or some
2oE from the planetary NGC 2867. This wonderful
near equally bright blue / bluish pair can be seen in 7.5cm
but is fairly attractive in 15cm or 20cm. Magnitudes were
visually estimated as 7.8 and 7.9, but the latest Tycho
data suggests it is brighter than this giving 6.82V and
Russell discovered this pair on the night of the 5th March 1873, describing it as “8 and 8” appearance in the field saying “This is the following star of a small triangle.” In the telescope I could not identify these stars.
Up till the last measures in 1977, the pair seems to be fixed, but there is evidence that now shows direct motion that has increase +4o to position angle 34o. However, the separation is clearly closing. In 1880 this was 2.5"arcsec and this has reduced to 1.9"arcsec. If the trends continue, the stars will become difficult in about 2200AD with closest approach being in 2340AD. Spectral Class of both is B8V. An attractive and enticing duo in a field of scattered stars..
He2-32 / Sa3-9 / ESO 166-19 / Wray 16-49 / PK 278-4.1 / PNG 278.5-4.5 (09309-5737) is a faint PNe that is listed as 16.1p and subtends some 56"x31". Double star R123 lies within the same field some 28'SE (PA 137o). It is likely invisible to most amateur telescopes except perhaps the larger Dobsonians.
RST 413 (09335-5823) lies 25'S of R 123’s position and is a very difficult pair that would be a true challenge for any southern amateur to either see elongated or clearly separated. If the Hipparcos separation of 0.396±0.002"arcsec, however, is true then it is unlikely to be split. I have never divided this pair R.A. Rossiter found this pair in 1929 and it has been measured five times in the ensuing years. The star at low magnification looks like a 7.2 magnitude blue star. When divided, the stars appear visually as 7.9 and 8.0 mag, however more recent photoelectric estimates give 8.10 and 10.04. Since found the separation remains unchanged at 0.4"arcsec, but the position angle seems to be prograde and now orientated at 237o. A pair to watch in the future to see if the two are attached.
GW Car (09364-5959) is an
EB/KE* eclipsing binary that lies in the same field as the
planetary IC2501, some 1.9' along PA
287o. Visual magnitude variations
change between 9.55 and 10.1 in the period of 1d 03h 05.6m
(1.128911 days.), based on the starting date on the 23rd
October 1941(JD 2430291.0395). The blue B1 III star show
nebulose characteristic in the spectra, suggesting that the
stars are, or have been, in the process of mass
* KE classification is a contact binary whose components have early spectral types in the range of O-types and A4 spectral types.
R133 (09432-8120) has magnitudes 9.5 and 9.5 was first discovered by H.C. Russell from Sydney Observatory on the 26th May 1880. His observation is given as 3.5"arc sec and the PA of 44o. In 1983, the separation was measured at 3.65"arcsec while the PA was given as 46o, indicating little change. This is a delightful even pair, with yellowish components. As both have similar common proper motions, it is likely that these stars maybe associated. If it is a true binary then the period is probably very long.
HJ 4240 (09433-6002) is an 8th and 10th magnitude pair 34'E of the small planetary IC2501. Although discovered by Sir John Herschel, Lawrence Hargrave made the first measures at Sydney Observatory on the 12th May 1882. Separated by 12.4"arcsec at PA 57o, little has changed in the positions in the last 116 years. I saw the colours as bluish and white, which is easily visible in 7.5cm According to the WDS96, the magnitudes are 7.5 and 10.0, with the primary's spectra being B5V.
W UMa / W Ursa Majoris (09438+5557) is one of the most famous and interesting of the EW eclipsing binary systems that is not visible from Sydney's -33o latitude. W Ursa Majoris varies from 7.9v to 8.63v over 0.3333639 days - or nearly exactly 8 hours. Both appear as dwarf F8V spectral class stars, both containing peculiarities in their spectrum. W UMa has the true separation of 3.6 million kilometres, each with diameters of 2.6 and 1.1 million kilometres, respectively. Luminosities are comparable with the Sun, being 1.3 L and 0.8 L, while both the temperatures are 5 920K and 6 140K and masses are 1.3 M and 0.76 M. Both stars appear grossly distorted, surrounding the whole system with a bright glowing gas, torn either by mass transfer between the stars or material is stripped from their surfaces. Some of these energies appear strongly in X-ray. Distance to W UMa is 55pc. or 180ly. from us.
Upsilon Carinae / υ Car /
RMK 11 (09471-6504) is one of the brightest
double stars in the southern skies and rates among the
very best pairs for small apertures. Discovered by
Charles Rümker and later measured by John Herschel
in 1836 this magnificent double star is listed as 3.0
and 6.0 visual magnitude on a continuing virtual fixed
position of 5.0"arcsec along the
128o position angle.
Both stars are pale bluish-white to white and yellowish
- though some say the companions colour is yellow
being likely a slight contrast effect but does agree
with the spectral class of A8Ib or A9.
E.J. Hartung says of this pair;
...there has been no real change in this very fine pair, and the proper motions are sufficiently similar to indicate a long period binary. It is an admirable object for small apertures.Canberra observer Ross Gould in "Seeing Double" (Southern Astronomy, Mar/ Apr 1994 pg.52-53)
The 18cm refractor showed it as an easy and beautiful pair at x180.This is a wonderful pair especially as it shares the field with the faint and just as easy HJ 4252. The main star of υ Car is catalogued as HIP 48002 / T8950:2272:1/ PPM 357553/ SAO 250695/ HD 85123 whose exact position is RA: 09h 47m 06.14s and Dec: -65o 04' 19.3" and the given visual magnitude is 2.92 with a B-V of +0.273. Tycho gives the primary as 3.01V magnitude and the B-V of +0.267.
HJ 4252 (09478-3507)
lies only 5.4'SE (PA 123o)
from Upsilon (υ) Carinae / RMK 11. This
bluish-white stars are 9.3v and 9.5 magnitude (or
8.74V and 9.13V) and are presently separated by
12.2"arcsec along PA 303o.
Both stars continue to slowly reduce in distance,
going from the Herschel measure of 13.0" (1836) to
12.2" (1991). As the proper motions are similar,
it is likely these two stars are attached. Assuming
the parallax is 12.10±0.84mas is correct,
being the distance of 83.3±5.9pc
(279±19ly.), then the true separation is now
around 1 100 AU with the a period being around of
20 000 years.
Hartung (AOST1) states under his description of Upsilon Car;
...a small pair h.4242 (9.3 9.5 12" 303o) almost 5'Sf. is also easy.Ross Gould in "Seeing Double" (Southern Astronomy, Mar/Apr 1994 pg.52-53) states;
...5' South-east is HJ4252, a wide faintish fixed pair...[and] showed well with 18cm at 180x.This is interesting pair that shares the same field as υ Car that best is seen using medium to moderately high magnification. A true southern splendour.
Δ81 / DUN 81 (09543-4517)
also known as Bode star 524 Argus, is one of the most
magnificent jewels of the southern sky and not to be left
out of in any southern observer's object lists. Hartung
describes it as ornaments, a lovely field, a real
treat to see.
I saw the colours as "pale yellow and bluish". I saw these two's colour a little more prominent than when Dunlop saw the pair in 1827. Dunlop measured the pair first, but for some reason the first recognised measures were achieved by John Herschel in 1836 (as stated in AOST2). Dunlop actually did measure this star first, giving the PA as 30o 34'sp. equally the PA of 270o - 30.57o = 239.4o and 4"arcsec. Little change has occurred in these star since Dunlop found the duo in 1836. Presently the PA is 240o with the separation of 5.4"arcsec, and the stated magnitudes are 5.8 and 7.9. As there is little movement in positions it is uncertain if these two are connected, but there is evidence of similar common proper motion. If they are really attached the period will be very long.
Southern Astronomical Delights © Andrew James 2003 Sydney, Australia