Double Star of the Month Archive 2016

In this series of short articles, a double star in both the northern and southern hemispheres will be highlighted for observation with small telescopes, with new objects being selected for each month.

December 2016 - Double Star of the Month

pi Arietis (02 49 17.55 +17 27 51.5), also known as STF 311, is a very unequal triple and as such probably needs 10-cm to see all three well. The stars are magnitudes 5.3, 8.0 and 10.7, and the separations of AB and AC are 3".2 and 24".1.

AB first came to the attention of the elder Herschel in 178x and is listed as H I 64. Sissy Haas notes that this pair was not seen in 12.5-cm, but Admiral Smyth is enthusiastic about this superb trio. Pale yellow, flushed and dusky is his conclusion on the star hues.

The proximity of pi Ari to the ecliptic has resulted in lunar occultations occurring and it was during one of these events that a close companion to A was found. A also appears to be an SB1 but it seems unlikely that this is the occultation pair so A would appear to be a group of 4 stars.

Looking much further out David Arnold finds a mag 10.5 star at 220" whilst Tofol Tobal has imaged stars of mags 14 and 15, at respectively 14".2 and 17".5 from A.

DUN 16 = f Eri (03 48 35.88 -37 37 12.6) is a member of the Tucana/Horologium + Columba moving group - a cadre of bright stars with similar space motions which are between 37 and 65 light years away from the Sun.

The pair consists of a magnitude 4.7 B8 dwarf paired with a 5.3 magnitude A1 dwarf. The separation has increased from 7" in 1826 to 8".4 in 2009 whilst the position angle has changed from 202° to 216° in the same interval.

The significant proper motion of star A would have moved it further away from B had B been a field star, rather than a binary companion, as seems to be the case.

One star is possibly a beta Lyrae-type eclipsing binary. The revised Hipparcos parallax gives a distance of 50.8 parcsecs. Ernst Hartung says that This beautiful pale yellow pair dominates a field of scattered stars and is a fine sight with 7.5 cm. Sissy Haas calls it a Showcase pair.

Bob Argyle - Double Star Section Director

November 2016 - Double Star of the Month

Iota Cas (02 29 03.96 +67 24 08.7) can be found by extending the line between delta and epsilon Cas by the same distance again. It was originally observed by William Herschel in 1782 as a 7" pair (H 3 4); he missed the closer component B (1".5) on that occasion but found it in 1804 (H I 34). As it has widened considerably since then, B is now easier to see.

Smyth gives the colours as pale yellow, lilac and fine blue whilst Webb restricts himself to yellow, blue and blue. Measures by the writer in 2015 give 232 degrees and 2".9 for AB and 120 degrees and 7".1 for AC. With a small aperture, B and C are delicate objects. The WDS gives magnitudes of 4.63, 6.92 and 9.05.

Orbital motion has reduced the position angle of AB some 60 degrees in 200 years and an orbit for it indicates a period of about 620 years, although one recent report argues that the motion of B relative to A is linear. The separation of AB has not changed in a smooth fashion but rather B appears to execute a loop every 50 years with respect to A. In fact, it is star A which has a faint K-type companion and it was first directly detected in 1982. This star is visual magnitude 8.5 and is separated by about 0".5 from A. Another companion, this time to C, was found in 2006, also at a distance of about 0".4 and this is probably an M dwarf.

Stars in the Dunlop catalogue, denoted by a capital Greek delta (Δ) are mostly very bright and wide and therefore constitute an excellent introduction to the double stars of the southern hemisphere.

Number 7 in that catalogue, DUN 7 (02 39 39.84 -59 34 02.9), is a rather faint member of its class (the mags of A and B are 7.56 and 7.66 in SIMBAD) but for the larger telescope aperture it does boast a close star to B which was discovered by Robert Innes. The primary, A, is a late G or early K giant of visual mag 8.0 and has a mag 8.9 companion about 36" away in PA 97 degrees. Although the Hipparcos parallax for each star differs by an amount somewhat greater than the quoted errors, the similarity of the proper motions indicates that this is almost certainly a physical system, and is located about 700 light years away.

In 1926, whilst measuring BC, W. H. van den Bos estimated the colour of A as between yellow and orange and considered this was equivalent to a spectral type of about K0. He gives the spectrum of B as A5. BC has mags of 8.0 and 8.9 and is currently separated by 0".4 and, although the system has not been measured for 20 years, there is significant angular motion.

Bob Argyle - Double Star Section Director

October 2016 - Double Star of the Month

STF3050 (23 59 29.33 +33 43 26.9) is a beautiful pair of white stars forming a long period binary system to the north of the Square of Pegasus. More specifically, it is 5 degrees north of and 2 degrees preceding Alpheratz (alpha And).

The components are mags 6.4 and 6.8 and the spectral type of star A is F8V, whilst that of B is likely to be similar. The first observation in the WDS is for 1777 representing the discovery of the system by Christian Mayer. It is the 80th and last entry in his pioneering double star catalogue. William Herschel later recovered it on December 13, 1787 and called it H N 58.

Thomas Lewis in his book on the Struve stars published in 1906 said it was evidently a binary, whilst Burnham in his General Catalogue of the same year notes apparently rectilinear motion. Subsequent observations have proved Lewis right and the pair is now significantly wider than it was at the beginning of the last century when it closed to less than 2". An orbit produced in 2011 by W. Hartkopf predicts a period of 717 years, with a position in late 2016 of 340 degs and 2".4. This makes it an easy target for 75-mm apertures and above.

Lewis noted that both stars were yellowish.

Beta PsA, (22 31 30.33 -32 20 45.9) bemoans Jim Kaler on his Stars website, is a neglected object most likely all alone, apparently unloved by a companion, or, for that matter, by astronomers and he compares it unfavourably with the much more referenced star alpha PsA.

Beta is certainly a fine double star and worth a visit, and the question of whether it is binary or not can be settled by considering the proper motions of the two stars.

The Hipparcos satellite reveals than A (mag. 4.3) is 143 light years away and moves across the sky, mostly to the east, at about 60 milliarcseconds per year. Star B has an almost identical proper motion and radial velocity and so is physically connected to A. Over the last 200 years the separation has reduced from 35".3 to 30".6 and the PA is almost fixed at 172 degrees.

The SIMBAD spectral types of A1 and G1 might suggest stars of white and pale yellow when in fact the observed colours (by Hartung) are given as pale yellow and white, although he notes that B sometimes appears reddish.

Bob Argyle - Double Star Section Director

September 2016 - Double Star of the Month

Located in Cepheus, STT 461 = 15 Cephei (22 03 53.86 +59 48 52.5) offers a stellar grouping which more resembles an asterism than a multiple star. On the basis that a picture is worth a thousand words, an image from the POSS Quick V survey is appended showing the main components of the group.

15 Cephei - Image Courtesy the Digitized Sky Survey
This image was provided by the Digitized Sky Survey.

STT 461 is located close to the galactic equator and can be found about 2 degrees north-west of the orange supergiant zeta Cep. (mag. 3.4), the most south-easterly of the five bright stars in the pentangle of Cepheus. W. J. Hussey, who re-observed the complete STT catalogue using the Lick 36-in (1901) merely measured AB and the 9th magnitude companion C. The WDS lists eight stars to mag 14.3; the primary star is a hot B1 dwarf of magnitude 6.6 and has B (mag 11.4) 11" distant in PA 297. C which is a K0 giant is 90" away in PA 40. There is little relative motion in the group, which, if the stars are all at the same distance as A, lies about 1500 light years away.

One of S. W. Burnham's earlier discoveries (BU 172), made with the 6-inch Alvan Clark refractor, was 51 Aquarii (22 24 06.87 -04 50 13.2). At that time Burnham's telescope was not fitted with a micrometer so his friend and colleague, Baron Ercole Dembowski in Italy measured the pair for him. In 1875 the two stars were at PA 20 degrees and separated by 0".46 so offered a tough test for Dembowski's 7.5-inch refractor.

The pair then slowly closed through most of the last century, reaching a minimum distance of 0".11 around 1987 when the position angle was changing by 20 degs per year. A good set of speckle measures since then means that the orbit is now tolerably well-known. The period is 145 years and at the time of writing the separation was just under 0".5 and widening, with the companion almost at the point in the orbit where it was discovered last time around.

A good 20-cm should show the pair but its fairly low altitude means the air needs to be steady. On 1782 Oct 2, William Herschel noted three faint and distant companions to 51 Aqr, but the duplicity of the primary star, then close to its maximum separation of 0".6, escaped him.

Bob Argyle - Double Star Section Director

August 2016 - Double Star of the Month

STF 2690 (20 31 11.94 +11 15 37.7) was found by William Herschel in 1779 and he called it H III 16. Since that time the position angle has reduced 26° to 255° and the separation has increased from 15" to 17".6.

Located in Delphinus it can be found just 30 arc mins preceding epsilon Del. Also in a low power field is 1 Del (BU 63) an unequal close pair which is a test for 15-cm.

The components of STF 2690 are mags 7.1 and 7.4 and Sissy Haas called them both 'peach-white'. Whilst observing at George Bishop's observatory, at South Villa in Regent's Park, London, W. R. Dawes noted .. on the first night on which I measured this object with Mr. BISHOP's 7-inch refractor (1840, Oct 27) I perceived that B was unquestionably wedge-shaped, and succeeded in obtaining moderately good measures of it. Dawes also speculated on why Struve has missed this pair during the Dorpat survey, and suggested that pairs such as STF 2690, being wide and easy, were only measured on poor nights and hence the real nature of star B would have eluded him.

DA 1, as the close pair became known, has a highly eccentric orbit and the separation ranges from 0".55 to 0".02, a distance which it attained in the last years of the previous century. It is now widening and in mid-2016, the separation is expected to be 0".34. The stars are mags 7.9 and 8.0 so this will be a severe test for 30-cm. A is also a very close pair being found in speckle survey of B stars in 1983. Motion appears slow and the period is likely to be a century or more.

Rho Capricorni (SHJ 323 - 20 28 52.19 -17 48 49.2) is the northernmost of a bright triangle of naked-eye stars about 5 degrees south-south-east of beta Capricorni. Of the other two, omicron featured in this column in 2015, and pi will appear in 2017.

Although discovered by the elder Herschel the pair now has the moniker SHJ attached to it - the name for stars catalogued by James South and Sir John Herschel.

This is a binary of period 278 years which is now widening but will remain quite a difficult object for the northern observer. The writer has not yet observed it but with a magnitude difference of 2 between the brightest components and a separation of 1".8 then it requires a good night to be seen.

There is a 13.3 star at 55" (distance increasing) and a 6.7 mag star some 259" away (and increasing) has, in turn, a companion of mag 10.6 at 54" and is catalogued as DOB 13DE.

Sissy Haas notes that A and D are pretty - Bright Sun-yellow and pale rose-red.

Bob Argyle - Double Star Section Director

July 2016 - Double Star of the Month

39 Dra (17 57 12.56 -30 22 24.80) can be found about 4 degrees following and slightly north of xi Dra in the 'head' of Draco. It is also known as b Dra.

The binocular user will see a pair of mag 5.1 and 8.0 stars separated by about 89". Any aperture larger than 6-cm will show the companion to A which William Herschel found in 1780 and allocated to his class 1 i.e. between 0 and 2". Since that time the pair has widened with increasing position angle and in 1993 was found at by the writer at 351° and 3".9. The AB stars are magnitudes 5.1 and 8.1 so it requires good seeing to see B clearly.

This is a quintuple system since all 3 bright stars are physically connected and both A and B are spectroscopic binaries. Surprisingly, although the motion in AB amounts to just 25 degrees in 230 years, a highly speculative orbit with a period of 3962 years appears in the USNO Sixth Orbit Catalogue.

In October 2011, John Nanson found the primary was a distinct yellow watered down by a weak touch of white, I could see a slight tinge of blue in "B" and "C" was just weakly white. There is much more information on this system on the Starsplitters website.

PZ 6 (17 59 05.28 -30 15 10.8) is a beautiful pair which lies about 1.5 degrees due west of gamma Sagittarii. In the 1st edition of the Cambridge Double Star Atlas it is given as PZ 4 but is corrected to PZ 6 in the second edition.

An observation of this pair on the evening of 5 September 2013 using the Johannesburg refractor showed the colours of the stars to be deep yellow and lilac.

The WDS gives spectral types M1Ib and G8II so this is a rare pairing of a supergiant and a giant. There is little motion between the two stars and the primary star sits a little over 1,000 light years away but with an uncertainty in the distance of 30%.

The stars are magnitudes 5.4 and 6.0, and the current separation of 5".7 appears to indicate that the stars have been slowly closing since the first measure in 1826. A 13.2 mag star at 25" was measured by the writer in September 2013.

By moving the telescope another 1.5 degrees further west, and crossing the border from Sagittarius into Scorpio, the observer will come across PZ 5 - another bright wide pair easily resolvable in a small aperture. The stars are mags 6.7 and 8.2 and both white - the spectral types are A3 and B9. Note, however, that PZ 5 is not labelled in CDSA 2 whilst it is in the first edition. The position in 2013 as determined by the writer was 104° and 5".7. On the same night a mag 11 companion was also noted at a distance of 49".

Bob Argyle - Double Star Section Director

June 2016 - Double Star of the Month

16/17 Dra (16 36 13.72 +52 55 27.8) is a 90" binocular pair to be found about 15 degrees preceding the head of Draco and the stars are of magnitude 5.4 and 5.5. William Herschel noted that A itself was a rather unequal but easy pair 4" apart, and he included it is his 1782 catalogue as H I 4. He reported that It is the star to which a line drawn from nu through mu points, at nearly the same distance from mu as mu from nu. The brighter star was recorded as white whilst the fainter was 'white inclining to red'. In mid-2015 the writer found the position angle 106 degs and the separation 2".9. The angular motion is but 8 degrees and the stars have closed up from 4" at discovery. All three components appear to be physically connected.

COO 197 (16 25 17.59 - 49 08 52.2) is a rather faint pair (mags 8.1 and 8.2) in southern Norma, near the border with TrA, which appeared in the catalogues of stars compiled at Cordoba Observatory.

It was first measured as double by R. P. Sellors at Sydney in 1895 using the 11.5-inch refractor. It was found to be in slow direct orbital motion and in 1977 an orbit was calculated with a period of 311 years. In 2008 the writer observed it with the large refractor in Johannesburg and at that time the observed position angle and the calculated value differed by more than 20 degrees. Andreas Alzner then performed a re-calculation of the elements of apparent orbit and found that the period was much longer (1132 years). In mid-2016 the stars will be found at 93 degs and 2".3.

In recent years, observations of this system with high resolution techniques and large telescopes have revealed that it is quite a complex multiple star. Using the NACO infra-red camera on one of the 8.2-metre VLT telescopes in 2004, Chauvin and colleagues found that B was again double at a distance of 0".1. The image in the journal shows the two stars clearly separated, but nearby star A appeared single. However, in 2014 Andrei Tokovinin also resolved A into two unequally bright stars separated by 0".1. It appears likely that there is also a spectroscopic sub-system in either Aa or Ab but which of the stars it can be pinned to is not yet determined. A 12th mag star now at 77 degs and 20" is being left behind.

Bob Argyle - Double Star Section Director

May 2016 - Double Star of the Month

Virgo straddles the celestial equator and this month two pairs are included from this constellation - one north and the other south of the zero line of declination.

The primary of STF 1764 (13 37 44.01 +02 22 56.5) is a K2 giant and the note in Sissy Haas' book says that the stars are yellow and blue and that the colours are vivid. This system has been left out of Hartung and the Rev. Webb dismisses it with the comment yellow and ash.

The pair can be found about 3 degrees north and slightly following zeta Virginis. It forms an equilateral triangle with 84 and 78 Vir. There has been very little change since discovery. The stars are mags 6.8 and 8.6 and last year the writer measured the pair and found PA 32° and separation 16".2. The distance of A has been measured by Hipparcos but the resulting large value (2038 light years) is very uncertain. There are two further and fainter companions 10.4 at 139° and 172" (C) and D 10.7 at 143° and 207" (D), which together form the pair STF 1765.

SHJ 162 (13 14 55.85 -11 22 07.3) misses the cut in both Webb and Hartung but Haas was obviously impressed by the colours of the two wide stars A and B - white and pale red. John Nanson, however, using a 6-inch f/10 lens and x84 in 2011, noted that they were yellow and white.

It was measured by James South on 1823 May 7 using his 5-foot equatorial when the distance of AB was 45". The writer has not observed this pair but apart from AB there is another star in the system, close to A which was discovered by Richard Rossiter from Bloemfontein in 1937 using the 27-inch refractor. This has turned out to be a binary of period 122 years and in mid-2016 the companion (a) is at 161° and 0".55. It is about 1.5 magnitudes fainter than A but might be seen in 30-cm on a good night. The rapid proper motion of Aa (0".37 per year - distance 128 light years) is leaving behind star B which is now 112" away. There is a star of mag 13.3 at 67". The system is 3 degrees directly preceding Spica.

Bob Argyle - Double Star Section Director

April 2016 - Double Star of the Month

STF 1517 (11 13 41.22 +20 07 44.9) is very easy to find. It is about 30 arc minutes south and slightly west of the 3rd magnitude delta Leonis. Found by F. G. W. Struve at Dorpat, this binary appears to be moving in an orbit which is very highly inclined. Motion is therefore mostly in separation and between 1820 and the late 1890s the stars closed from more than 1 arc second to about one-quarter of an arc second. After that the quadrant changed and they began to separate. The proper motion of the system is large enough that we can say the system is definitely physical. The USNO Sixth Orbit Catalogue gives a period of 924 years which is highly speculative as the motion has been virtually linear since discovery.

The calculated position for early 2016 is 316° and 0".71 making it a good test for 20-cm. The stars are of similar brightness but a little on the faint side (mags 7.5 and 8.0). As part of his proper motion programme, Burnham added a star of mag 10.8 at 246" and 97° but the distance is increasing rapidly due to the proper motion of 0".4 annually in the bright pair.

BU 28 (12 30 04.93 -13 23 35.0) is one of Burnham's most interesting discoveries. Its low number tells us that it was in Burnham's first list of 81 new pairs which he published in MNRAS in 1873. Burnham often underestimated the magnitude of the fainter star in very close and unequal pairs and in this case he assigned a value of 12 to the magnitude of B, calling the pair a very delicate and beautiful double star. The WDS gives 9.6 with the primary at 6.4. It is marked in the Cambridge Double Star Atlas 1st edition but without a label.

This is a pair with a period of 151 years and the separation ranges from less than 0".4 to 2".2 which, fortuitously, is where it is at present, so now is the very best opportunity to observe these stars. It is found 3 degrees due north of delta Corvi, but the low declination from the UK means that a good steady night is required. The writer has not yet looked at this system but will put it on his 'to do' list. BU 28 is 80 light years distant and moving across the sky at more than 0".25 per year. It is leaving behind two distant comites (mags 10.6 and 11.6) which are currently both 71" distant.

Bob Argyle - Double Star Section Director

March 2016 - Double Star of the Month

STF 485/STF 484 (04 07 51.38 +62 19 45.4) are really just part of the open cluster NGC 1502 (H VII 47).

Sketch of NGC1502 and the double star STF 485 by Matt Heijen
This sketch is reproduced courtesy of Matt Heijen who observed the area in December 2008 with his Orion Optics 30-cm telescope at x94 with a 52 arc minute field of view.

For the small telescope user this is a pretty sight but its appears to be a real headache for the double star cataloguers and there is an extensive entry in the WDS catalogue notes trying to sort out which stars are which, and who discovered what.

The brightest pair is STF 485 AE which consists of stars of mags 6.91 and 6.94 separated by 17". There are a further 5 comites of magnitude 10 or brighter within 140" of star A. Two of these, mags 9.63 and 9.81, form STF 484 at 336° and 22".8 (visible on the drawing to the east of the cluster centre). Recently, Andrè Debackére measured a new component in one of the pairs in this group (see DSSC 24 on this website).

For the astrophysicist, the most interesting star is E. This turns out to be a multiple star consisting of a 2.69 day Algol system with a third star (but also a close binary) 0".1 distant circling the two every 54 years. The total mass in this system is more than 50 suns. The GCVS gives the name SZ Cam to the variable but ironically the distance derived from the dynamics of the 54-year system place the stars over 300 pc further than the accepted distance of 800 pcs to the cluster. There is little colour in this grouping as many of the components are hot early B stars.

15 Hya (08 51 34.44 -07 10 38.0) is an object which I have not yet observed but which in terms of separation and magnitude difference looks like a tempting target.

The star first entered the double star catalogues as H V 120 when William Herschel noted on 1782 Dec 28 that it appeared Extremely unequal with the brighter star white and the comes red whilst the separation was 43 arc seconds.

The WDS gives magnitude 11.4 for the fainter star but relegates it to component C as in 1878 S. W. Burnham found that the primary was a close double (0".47) whose components he estimated had magnitudes 5.7 and 7.2. Since then the close pair has widened significantly and is now more than 1" apart so it should be visible in 15-cm in the UK; the seeing needs to be good as the declination counts against it.

Burnham adds a further faint star of mag 12.1 at 55". AB is clearly a long period binary and the position angle has decreased to 121 degrees in 2003 although there do not appear to have been any measures since then.

Bob Argyle - Double Star Section Director

We have had an observation submitted for STF 485. If you have observed this double star – or the cluster it is in – please let us know.

February 2016 - Double Star of the Month

38 Gem (06 54 38,63 +13 10 40.1) can easily be swept up since it directly follows the 3.4 mag xi Gem by a little over 2 degrees.

The current orbital period, 1898 years, as determined by Brian Mason in 2014, is clearly very uncertain but the position for 2016.0 is 143° and 7".31 in close agreement with measures by the writer late last year. The stars are of visual magnitude 4.8 and 7.8 so the quadrant in which B lies is certainly the second whilst Sissy Haas puts it in the 4th.

Admiral Smyth gives light yellow and purple, but E. J. Hartung sees yellowish and pale-orange, whilst to Sissy Haas the colours appear lemon-white and greyish.

A third, much fainter star C of mag. 11.3 can be seen at a distance of 119" whilst Andrei Tokovinin noticed a 15.0 mag dot at 151". The primary, a dwarf star of spectral class F0 is 96 light years away.

STF1121 (07 36 35.71 -14 29 00.3) is not a double or multiple star - rather it forms the bright core of the open cluster M47 in Puppis.

This cluster was discovered by the Italian astronomer Giovanni Hodierna sometime before 1654. As well as finding a dozen or so deep-sky objects before Messier catalogued them, Hodierna also compiled a small list of double stars.

The WDS contains 26 entries to cover this system and its large array of comites, but the small telescope user will easily be able to see AB (6.9, 7.3 at 300° and 6".5), whilst amongst the more obvious comites D is mag 9.5 at 72" (distance increasing), E is 9.9 at 70" (distance decreasing) and G is 7.7 at 82".

It is perhaps best seen with a pair of large binoculars. A report on the Cloudy Nights website for 2004 notes that the AB pair can be split easily with Celestron 25 x 100s. M47 and nearby M46 can be swept up in a wide-field telescope by moving 20 degrees due south of Procyon.

Bob Argyle - Double Star Section Director

January 2016 - Double Star of the Month

STT 147 (06 34 19.37 +38 04 33.6) is located in Auriga and is about 35 arc minutes south preceding the very red star UU Aur which is visual magnitude 5.3 and has an exceptional B-V colour index of +2.6. The field can also be found from the bright binary theta Aurigae by moving about 9 degrees due east. Burnham describes it as an almost equilateral triangle with the sides being about 40" long and the stars A, B and C being respectively 6.8, 8.7 and 9.9. Sissy Haas notes that A is bright orange and indeed the spectral type of this star is K0.

When the pair was first observed by Otto Struve at Pulkovo he also noted that C was a very close and difficult pair. The WDS gives the magnitudes as 10.6 and 11.0 with PA 109 and separation 0".5. There seems to be little motion in this system. Burnham notes that it was 'difficult' in the 18.5-inch Dearborn refractor and no measures have been made since 1957.

So here is a challenge for the larger aperture user and a real test of the seeing and transparency. Another neat pair (STF 928) can be found 27' north following, mags 7.9 and 8.6 at 131 degs and 3".5. These stars have common proper motion and appear to form a binary pair. An unconnected mag 12.4 can be found at 124 degs and 131" to B.

HJ 3857 is in Columba (06 24 01.02 -36 42 28.4) about 2.5 degrees south following the 4.4 magnitude kappa. This is also an easy triple although star B did not appear to Dunlop when he recorded this pair as number 28 in his catalogue, but was swept up a few years later by John Herschel at Feldhausen.

The WDS catalogue values for the magnitudes are 5.7 (A), 9.8 (B) and 6.9 for C. The Dunlop component would appear to be a field star and has moved 6" closer to the closer pair over the last 2 centuries or so. Gould, using 175-mm, notes that the primary is orange and the wider companion is bluish.

Bob Argyle - Double Star Section Director