Messenger No. 55 (March 1989)

« Back to The Messenger home

1-2 (PDF)
H. Schwarz
The Southern Crab.

ADS BibCode:
Schwarz, H.
The objeet under serutiny in this artieie - a suspeeted symbiotie star with the prosaie name of He2-104 - looks far more like a erab than the Grab nebula. A quiek look at Figure 1 will eonvinee you that the name Southern Grab is most suitable and fully deserved! Our seareh for sueh objeets was started by seleetion of speeial eases in the adapted emission line ratio diagram used by Sehwarz (1988). Four possible pratoplanetary nebulae were found of whieh He2-104 is by far the most speetaeular example.
Allen, D.A.; Mon. Not. R. Astr. Soc. 204, 113
Allen, D.A.: Proc. Astr. Soc. Austr. 5, 369
Morris, M.: Publ. Astr. Soc. Pac. 99, 1115
Schwarz, H.E.; in IAU Coll. 103, 123 (1988).
Whitelock, P.A.: in IAU Coll. 103, 47 (1988).
2-4 (PDF)
H. van der Laan
Key Programmes on La Silla: First Allocations

ADS BibCode:
van der Laan, H.
AA(Director General, ESO)
With the Observing Programmes Committee's recommendations in hand, early December last year, all information was available to allocate and plan the observations for Period 43 (normal programmes) and Periods 43 and 44 (Key Programmes). The scenario of preparations and decisions has precisely followed the intentions outlined in my original article in the Messenger of March 1988 (No. 51). Here the community is briefly informed about the procedures, the proposals and the allocations. Investigators of Key Programme Proposals successful in this first round will themselves describe their research plans in brief Messenger articles, starting with three such contributions in this issue and to be continued. Later in this article there is an overview of Key Programme time committed and time expected to be available for subsequent rounds, with the 15th of October 1989 as the next deadline.
5-6 (PDF)
V. de Lapparent et al.
A redshift survey of galaxies with z ⪉ 0.6 using multi-object spectroscopy. Profile of key programme.

ADS BibCode:
de Lapparent, V.; Mazure, A.; Mathez, G.; Mellier, Y.
AA(Institut d'Astrophysique de Paris, France) AB(Laboratoire d'Astronomie de Montpellier, France) AC(Observatoire de Toulouse, France) AD(Observatoire de Toulouse, France)
Through the steady acquisition of redshifts of galaxies, our understanding of the large-scale galaxy distribution has evolved drastically during the past decade. Most recently, the Centre for Astrophysics (CfA) redshift survey (B =5 15.5) has suggested a new picture of the galaxy distribution: galaxies appear to be distributed on thin shells surrounding vast regions with diameters between 20 and 50 h-1 Mpc (Ho = 100 h km S-1 Mpc-1) devoid of bright galaxies (de Lapparent, Geiler, and Huchra 1986). This new interpretation of the galaxy distribution is consistent with the detection of a 60 h-1 Mpc void in Boötes (Kirshner et al. 1981) and with the alternation of peaks and - 100 h-1 Mpc wide valleys in deep pencil-beam probes (Koo, Kron, and Szalay 1987). Shell-like structures are also detected in redshift surveys of HI galaxies (Haynes and Giovanelli 1986).
Butcher, H.B., and Oemler, A.Jr.: 1978, Ap.
J., 219,18.
Butcher, H.B., and Oemler, AJr.: 1984, Ap.
J., 285, 426.
Buzzoni, B., Delabre, B., Dekker, H.,
D'Odorico, S., Enard, D., Focardi, P., Gustafsson,
B., and Reiss, R.: 1984, The
Messenger, 38, 9.
D'Odorico, S. et al.: 1986, Proc. SPIE, 627,
Dressler, A, and Gunn, J. E.: 1983, Ap. J.,
Dressler, A, Gunn, J. E., and Schneider, D. P.:
1985, Ap. J., 294, 70.
Fort, 8., Mellier, Y., Picat, J.P., Rio, Y., and
LeliEMe, G.: 1986, Proc. SPIE, 627, 321.
Haynes, M.P., and Giovanelli, R.: 1986, Ap. J.
(Letters), 306, L55.
Kirshner, R. P., Oemler, A. Jr., Schechter,
P.L., and Shectman, S.A.: 1981, Ap. J.
(Letters), 248, L57.
Koo, D.C. 1986, Ap. J., 311, 651.
Koo, D.C., Kron, R.G., and Szalay, A.S.:
1987, in Thirteenth Texas Symposium on
Relativistic Astrophysics, ed. M. P. Ulmer
(Singapore: World Scientific), p. 284.
de Lapparent, V., Geiler, M.J., and Huchra,
J.P.: 1986, Ap. J. (Letters), 302, L1.
de Lapparent, V., Geiler, M.J., and Huchra,
J.P.: 1988, Ap. J., 332, 44.
Lavery, R.J., and Henry, J.P.: 1986, Ap. J.
(Letters), 34, L5.
Melott, A.L.: 1987, Mon. Not. Roy. Astr. Soc.,
Ostriker, J.P., and Vishniac, E.T.: 1986, Ap.
J. (LeUers), 306, L51.
Peebles, P.J. E.: 1980, The Large-Scale
Structure of the Universe (Princeton:
Princeton University Press).
Tyson, JA, 1988, Astr. J., 96, 1.
White, S. D. M., Frenk, C. S., Davis, M., and
Efstathiou, G. 1987, Ap. J., 313, 505.
6-8 (PDF)
R. Bender et al.
Towards a physical classification of early-type galaxies. Profile of a key programme.

ADS BibCode:
Bender, R.; Capaccioli, M.; Macchetto, F.; Nieto, J.-L.
AA(Landessternwarte, Heidelberg, F. R. Germany) AB(Osservatorio Astronomico, Padova, Italy) AC(Space Telescope Science Institute, Baltimore, USA) AD(Observatoire de Toulouse, France)
Hubble was the first who succeeded in classifying galaxies within a scheme of some physical meaning. Although it soon became clear that Hubble's tuning fork does not represent an evolutionary sequence, this essential diagram has proven to be a powerful tool especially for the understanding of late-type galaxies. On the other hand, the "early-type" sequence of elliptical (E) and SO galaxies is less satisfying, because it does not seem to reflect a unique sequence of physical properties. The SO class, although conceived to bridge the gap between disk- and disk-Iess galaxies, has often been abused to host ellipticals exhibiting peculiarities incompatible with their definition as structureless objects. For the elliptical galaxies themselves, "ellipticity" has been found to be essentially meaningless with regard to their angular momentum properties, and shows Iittle, if any, correlation with other global parameters. This fact became apparent after the first stellar kinematical measurements of luminous ellipticals (Bertola and Capaccioli 1975, IIlingworth 1977); E galaxies are not necessarily f1attened by rotation and may have anisotropie velocity dispersions (Binney 1978).
Barnes, J., Efstathiou, G.: 1987, Astrophys. J.
Bender, R.: 1987, Ph. O. thesis, University of
Bender, R, Möllenhoff, C.: 1987, Astron. Astrophys.
Bender, R.: 1988a, Astron. Astrophys. Letters
193, L7.
Bender, R: 1988b, Astron. Astrophys. Letters
202, L5.
Bender, R, Oöbereiner, S., Möllenhoff, C.:
1988, Astron. Astrophys. Suppl. Series 74,
Bender, R., Surma, P., Oöbereiner, S.,
Möllenhoff, C., Madejski, R: 1989, Astron.
Astrophys. in press.
Bertola, F., Capaccioli, M.: 1975, Astrophys.
J. 200, 439.
Binney, J.: 1978, Monthly Not. Roy. Astron.
Soc. 183,501.
Blumenthai, G. R, Faber, S. M., Primack,
J.R., Rees, M.J.: 1984, Nature 311, 517.
Burstein, 0., Oavies, R. L, Oressler, A., Faber,
S. M., Stone, R P. S., Lynden-Bell, 0.,
Wegner, G.: 1987, Astrophys. J. Suppl.
Series 64, 601.
Capaccioli, M.: 1987, in lAU Symp. 100:
Structure and Dynamics of Elliptical Galaxies,
Ed. T. de Zeeuw, Reidel, Oordrecht, 47.
Capaccioli, M., Held, E. V., Nieto, J.-L.: 1987,
Astron. J. 94, 1519.
Capaccioli, M., Vietri, M.: 1988, in Yellow
Mountain Summer School on Relativistic
Astrophysics and on the Origin and Structure
of Galaxies, preprint.
Carter, 0.: 1987, Astrophys. J. 312, 514.
Oavies, R L., Efstathiou, G., Fall, S. M., Illingworth,
G., Schechter, P.: 1983, Astrophys.
J. 266, 41.
Oavies, R L., Burstein, 0., Faber, S. M., Lynden-
Bell, 0., Terlevich, RJ., Wegner, G.:
1987, Astrophys. J. Suppl. Series 64, 581.
Ojorgovski, S., Oavis, M.: 1987, Astrophys. J.
Oressler, A.: 1980, Astrophys. J. 236, 351.
Oressler, A., Lynden-Bell, 0., Burstein, 0.,
Oavies, R L., Faber, S. M., Terlevich, RJ.,
Wegner, G.: 1987, Astrophys. J. 313, 42.
Fall, S.M.: 1983, in IAU Symp. 100: Internal
Kinematics and Dynamics of Galaxies, Ed.
E. Athanassoula, Reidel Oordrecht, p. 391.
Franx, M., Illingworth, G.: 1988, Astrophys. J.
LeUers 327, L55.
Jedrzejewski, R.I.: 1987, Monthly Not. Roy.
Astron. Soc. 226, 747.
Kruit, P.C. van der: 1987, Astron. Astrophys.
Lauer, T. R.: 1985, Monthly Not. Roy. Astron.
Soc. 216, 429.
Nieto, J.-L., Bender, R.: 1989, Astron. Astrophys.
in press.
Nieto, J.-L.: 1988, Invited Lectures at 2da
Reunion de Astronomia Extragalactica,
Academia Nacional de Ciencias de Cordoba,
in press.
Nieto, J.L., Capaccioli, M., Held, E.V.: 1988,
Astron. Astrophys. Letters 195, L1.
Prugniel, Ph., Oavoust, E., Nieto, J.-L.: 1989,
Astron. Astorphys. in press.
Sandage, A., Tammann, G.A.: 1981, A Revised
Shapley-Ames Catalog of Bright
Galaxies, Carnegie Institution of Washington,
Publication 635, Washington.
Silk, J.: 1983, Nature 301,574.
8-12 (PDF)
J. Surdej et al.
Profiles of a Key Programme: Gravitational Lensing

ADS BibCode:
Surdej, J.; Arnaud, J.; Borgeest, U.; Djorgovski, S.; Fleischmann, F.; Hammer, F.; Hutsemekers, D.; Kayser, R.; Le Fevre, O.; Nottale, L.; Magain, P.; Meylan, G.; Refsdal, S.; Remy, M.; Shaver, P.; Smette, A.; Swings, J. P.; Vanderriest, C.; van Drom, E.; Véron-Cetty, M.; Véron, P.; Weigelt, G.
AA(Institute ofAstrophysics, University of Liege, Belgium) AB(Canada-France-Hawaii Telescope Corporation, Hawaii) AC(Hamburg Observatory, F. R. Germany) AD(Astronomy Department, California Institute of Technology, Pasadena,USA) AE(Physics Institute of the Erlangen-Nürnberg University, F. R. Germany) AF(Meudon Observatory, France) AG(European Southern Observatory, La Silla, Chile) AH(CITA, University of Toronto, Canada) AI(Canada-France-Hawaii Telescope Corporation, Hawaii) AJ(Meudon Observatory, France) AK(Institute ofAstrophysics, University ofLiege, Belgium) AL(ESO, Garching, F. R. Germany) AM(Hamburg Observatory, F. R. Germany) AN(European Southern Observatory, La Silla, Chile) AO(ESO, Garching, F. R.Germany) AP(ESO, Garching, F. R.Germany) AQ(Institute ofAstrophysics, University ofLiege, Belgium) AR(Meudon Observatory, France) AS(European Southern Observatory, La Silla, Chile) AT(Haute-Provence Observatory, France) AU(Haute-Provence Observatory, France) AV(Physics Institute of the Erlangen-Nürnberg University, F. R. Germany)
Prior to Professor van der Laan's enquiry, in the March 1988 issue of the Messenger, on the general interest among astronomers from the European community to possibly participate in Key Programmes (KPs) at the European 80uthern Observatory, at least three distinct groups (including more than half of the above authors) were already involved in the study of "gravitational lensing" effects (see box on pages 10-11). Observations were being performed with the help of various telescopes on La 8illa as weil as at other observatories (VLA, CFHT, Palomar, Kitt Peak, etc.).
BorgeeSl, U.: 1986, Ap. J. 309, 467.
BorgeeSl, U., Refsdal, S.: 1984, A & A 141, 318.
Chang, K., Refsdal, S.: 1979, Nature 282, 561.
Chang, K., Refsdal, S.: 1984, A & A 132,168.
Fugmann, W.: 1988, A & A 204,73.
Gorenslein, M. V., Falco, E. E., Shapiro, 1.1.: 1988,
Ap. J. 327, 693.
Grieger, B.. Kayser, R., Refsdal, S.: 1986, Nature
Grieger, B., Kayser, R.. Refsdal, S.: 1988, A & A
Hammer, F., Notlale, L.: 1986a. A & A 155, 420.
Hammer, F.. Notlal , L.: 1986b, A & A 167, 1.
Hammer, F., Le Fevre, 0., Jon s, J., Rigaut, F.,
Soucail, G.: 1989, A & A 208, L7.
Hammer, F., Le Fevre, 0., Notlale, L.: 1987, in
Observational Cosmology: Proceedings or lAU
Symposium no. 124, ed. by Hewill et al., Reidel,
Dordrecht, 751.
Huchra, J., Gorenslein, M., Kenl, S., Shapiro, 1.,
Smith, G.. Horine, E.. Perley, R.: 1985, Astron. J.
Le Fevre, 0., Hammer, F., Notlale, L.. Mathez, G.:
1987, Na/ure 326,268.
Le Fevre, 0., Hammer, F., Notlale, L., Mazure. A.,
Christian, C.: 1988a, Ap. J. 324, L 1.
Le Fevre, 0., Hammer, F.. Jones, J.: 1988b, Ap. J.
331, L73.
Le Fevre, 0., Hammer, F.: 1989, in preparation.
Lynds, R., Pelrosian, V.: 1986, Bull. Amer. Astron.
Soc. 18, 1014.
Lynds, R., P Irosian, V.: 1988, Preprint.
Magain, P., Surdej, J., Swings, J.P., Borgeesl, U.,
Kayser, R., Kuhr, H., Refsdal, S., Remy, M.: 1988,
Nature 334, 325.
Meylan, G., Djorgovski, S.: 1989, Ap. J. (Letlers), in
12-13 (PDF)
H. van der Laan
The New Research Student Programme of the European Sothern Observatory

ADS BibCode:
van der Laan, H.
AA(Director General, ESO)
For many years ESO has appointed young astronomers as Fellows to work one to two years at Headquarters or on La Silla. The HO Fellows spend the greater part of their eftorts on personal research, the Fellows on La Silla split their time roughly 50/50 between their research and support astronomy duties. The ESO Fellowship programme has successfully contributed to the development of young scientists from member states into mature research astronomers. It has also promoted the interaction among investigators from many piaces and traditions, interactions that continue long after the collaborators have left their ESO posts. This postdoctoral Fellowship programme continues undiminished.
13-14 (PDF)
B. Marano
The Users Committee (UC)

ADS BibCode:
Marano, B.
AA(UC Chairman, Osservatorio Astronomico, Bologna, Italy)
The Users Committee meets as a rule once a year, in May. Besides the national representatives, the meeting is attended by the Director General and by the Heads of La Silla, of the Image Processlng and Measuring Machines and of the Visiting Astronomers Office. Other members of the ESO staff may attend, especlally If they are directly involved in some item in the agenda.
14-21 (PDF)
A. Blaauw
ESO's early history, 1953 - 1975. II. Searching for a site in South Africa.

ADS BibCode:
Blaauw, A.
AA(Kapteyn Laboratory, Groningen, the Netherlands)
Over a time span of more than seven years, with several interruptions from late 1955 to the middle of 1963, young European astronomers and their assistants have been engaged in the search for a site in South Africa. By the end of that time, it became clear that the observatory would not be built on this continent; the South American Andes Mountains offered superior observing conditions.
Abbreviations used:
EHA = ESO Historical Archives (see the description
in the previous issue of the
FHA = Files belonging to the Office of the
Head of Administration at ESO Headquarters.
EC = ESO Committee (the committee that
preceded the Council); for a list of the meetings
of the EC, see the previous article.
Heckmann Sterne = O. Heckmann, Sterne,
Kosmos, Weltmodelle, Verlag Piper & Co.,
München, Zürich, 1976.
[1] See the report on the site selection by
W. H. Stevenson and H. Knox-Shaw in
Monthly Notices R.A. S., Vol. 95, p. 447,
[2] In EHA-I.A.1.3. A paper presented at the
F/agstaff Conference on Photo-electric
Problems, Techniques, and Instrumentation,
Aug.-Sept. 1952.
[3] In EHA-I.A. 1.3.
[4] H. Siedentopf: Climate of the Union of
South Africa, Astron. Inst. of the Univ. of
Tübingen, 1955, in EHA-1. A. 1.3.
[5] Memo of this meeting in EHA-1. A. 1.3.
[6] A. Danjon and A. Couder, Lunettes et
Telescopes, Paris 1935, Chapitre V. See
also Comptes Rendus No. 183, 1032,
1926 for the calibrations.
[7] EHA-1. A. 1.3. A long report by Elsässer
to Heckmann, Siedentopf and Unsöld
accompanies this letter.
[8] See I. A. 1.5. and I. B. 3.
[9] See I.C.2.3.a.
[10] EHA-I.C.2.3.d.
[11] Comm. Obs. de Belgique (Ucc/e),
No. 141,1958.
[12] See minutes of a discussion on 25 July
1958 following the 8th EC Meeting in
EHA-I.A. 1.7.
[13] See minutes EC Meeting of July 1958,
item 13 in EHA-I.A. 1.7.
[14] See letter of J. H. Oort to the EC of Oct.
21,1958 in EHA-I.C.2.3.
[15] This report in EHA-1. B. 11. and
[16] See the minutes of this (12th) meeting of
the EC. The report by Muller seems to
be missing from the EHA.
[17] In EHA-I.C.2.5.d.
[18] The report is contained in the minutes of
the meeting.
[19] In EHA-I.C.2.2.a.
[20] In EHA-1. B. 11.
[21] See map EHA-f.A.1.16.
[22] EHA-I.C.2.7.b., H. Siedentopf and F.
Unz, Temperature Fluctuations in the Atmospheric
Ground Layer observed at
Zeekoegat and Flathill (South Africa),
March 1964.
[23] F. Unz, Mitteilungen Tübingen No. 116 =
Meteorol. Rundschau 23, p. 87, 1970.
[24] J. Dachs, U. Haug and J. Pfleiderer, Mitt.
Tübingen No. 87 = J. Atm. Terr. Phys.
28, p. 637, 1966.
[25] J. Pfleiderer, J. Dachs and U. Haug, Mitt.
Tübingen No. 88 = Zeitsehr. für Astroph.
64, p. 116, 1966.
[26] In EHA-I.C.2.7.b.
[27] See letter van Geelen to B/aauw of 11
November 1960 in EHA-I.C.2.8.d.
14-14 (PDF)
Tentative Time-table of Council Sessions and Committee Meetings in 1989

ADS BibCode:
21-21 (PDF)
The Benevolent Environment

ADS BibCode:
In the description of ESO's earliest history we encountered first of all the astronomers and their immediate collaborators. But their work would not have been possible without strong administrative support in Europe and the logistic services and hospitality of South African institutes.
22-24 (PDF)
Visiting Astronomers (April1-0ctober 1, 1989)

ADS BibCode:
22-24 (PDF)
L. Zago, F. Rigaut
Wind turbulence in the dome of the 3.6-m telescope.

ADS BibCode:
Zago, L.; Rigaut, F.
It is a common experience that telescope tracking may be affected by strang winds, as in some cases the air flow and its associated turbulence penetrate the dome with an amplitude sufficient to perturbate the smooth operation of the telescope. Reports of this phenomenon are, however, only qualitative as no measured data were available (to the authors' knowledge) on quantities such as mean flow penetration, turbulence intensity and vortex scale in a dome with an open slit. Only some recent wind tunnel tests [1] have addressed this question, although the reIiability of the results may be somewhat questioned because of the scale similarity problems of wind tunnel simulations with raund buildings.
[1] Kiceniuk T. and Potter K., Internal Air Flow
Patterns for the Keck 1O-m Telescope Observatory
Dome, GALCIT Report 10'
GWT-DR 1104.
25-28 (PDF)
T. Le Bertre et al.
IRC +10216: a peanut nebula!

ADS BibCode:
Le Bertre, T.; Magain, P.; Remy, M.
Carbon stars with low effective temperature (2,000-3,000 K) are thought to be long-period variables evolving on the Asymptotic Giant Branch (AGB). These objects are burning alternately hydrogen and helium in different shells around a degenerate core of carbon and oxygen [1]. Material processed during the helium burning phase is dredged-up by convection to the surface and enriches it in carbon relative to oxygen.
[1] Iben, I., Jr.: 1981, in Physical Processes
in Red Giants, I. Iben Jr. and A Renzini
(eds.), D. Reidel Publishing Company 3.
[2] Le Bertre, T.: 1988, Astron. Astrophys.
(3] Becklin, E. E., Frogel, J.A, Hyland, AR.,
Kristian, J., Neugebauer, G.: 1969, Astrophys.
J. 158, L 133.
(4] Dyck, H. M., Zuckerman, B., Howell, R R,
Beckwith, S.: Publ. Astron. Soc. Pac. 99,
[5] Le Bertre, T.: 1987, Astron. Astrophys.
176, 107.
(6] Skilling, J., Bryan, R. K.: 1984, Month.
Not. Roy. Astr. Soc. 211, 111.
(7] Magain, P.: 1989, in preparation.
[8] Heydari-Malayeri, M.: 1988, The
Messenger 53, 23.
28-28 (PDF)
Guidelines for Authors of Articles for the ESO Messenger

ADS BibCode:
The Messenger is ESO's house-journal and serves as a link between ESO and the user community. It brings information about scientific and technical developments at ESO and also about administrative measures. At the same time it aims at providing interesting news about astronomy and astrophysics to a broader public, ineluding policy makers, science teachers, amateur astronomers, inside and outside the ESO member countries. At the present time, the Messenger is distributed free of charge to about 4,000 addresses (airmail to overseas destinations).
28-28 (PDF)
List of ESO Preprints (December 1988-February 1989)

ADS BibCode:
625. (1) C. N Tadhunter, RA E. Fosbury, S. di Serego Alighieri: Beamed lonizing Radiation in Radio Galaxies. (2) R Morganti et al.: What Are the Emission Line Filaments Along the Radio Axis of Centaurus A? Papers presented at the Como Workshop on BL Lac Objects: 10 Years After (September 1988).
29-31 (PDF)
W. C. Keel
A Distant View of La Silla

ADS BibCode:
Keel, W. C.
AA(University of Alabama, USA)
The domes and related structures on La Silla are prominent features of the Atacama landscape as seen for many kilometres, and would be for many more were it not for the intervening Andean foothills. Under proper conditions, they may be seen (with the unaided eye) for even greater distances. Possibly the most distant normally occupied vantage point (barring a SPOT image) is from the Inter-American Observatory on Gerro Tololo, about 103 km south-southwest of La Silla. For month-Iong periods twice a year (when the sun's declination is about -10°) the domes at ESO are prominent shortly before sunset, as shown in tlle photograph taken in midOctober of 1988. Five structures are prominent with another two visible on the original print. Part of La Silla is hidden behind a foreground mountain, identified in t11e Mapa Fisico de Chile as Gerro EI Pozo (east of Almirante Latorre); its presence accounts for the greater difficulty of locating Gerro Tololo from La Silla, even using binoculars.
29-29 (PDF)
Staff Movements

ADS BibCode:
31-31 (PDF)
C. Madsen
The Changing of Skyline of La Silla

ADS BibCode:
Madsen, C.
The Changing of Skyline of La Silla
32-37 (PDF)
B. Reipurth, C. Madsen
Signposts of low mass star formation in molecular clouds.

ADS BibCode:
Reipurth, B.; Madsen, C.
Regions of massive star formation are easily recognizable because of the presence of bright, often very extended H11 regions. The more quiescent places where only low mass star formation takes place are not so immediately obvious to identify. Most of the low mass star forming regions known today were found in the 1950's, mainly through objective prism surveys for Ha emission stars done by Joy, Herbig, Haro and others. Their results are summarized and supplemented by later findings in a new catalogue by Herbig and Bell (1988), which Iists 742 mainly low mass pre-main-sequence stars. Another recent and rich source of low mass young stars is the IRAS catalogue. IRAS data towards clouds, however, often suffer from source confusion and, in particular, extraction problems because of background emission.
Bally, J., Langer, W.D., Stark, AA., Wilson,
R. W.: 1987, Astrophys. J. 312, L45.
Bührke, T., Mundt, R., Ray, T. P.: 1988, Astron.
Astrophys. 200, 99.
Cohen, M., Kuhi, L.V., Harlan, E.A: 1977,
Astrophys. J. 215, L 127.
Graham, J.A: 1986, Astrophys. J. 302, 352.
Herbig, G. H., Bell, K. R: 1988, Liek Observatory
Bulletin No. 1111.
Mundt, R: 1988, in Formation and Evolution
of Low Mass Stars, eds. A K. Dupree,
M.T.V.T. Lago, NATO ASI Series C vol.
241, p. 257.
Reipurth, B.: 1985, Astron. Astrophys. Suppl.
Reipurth, B., Bally, J.: 1986, Nature 320,336.
Reipurth, B., Bally, J., Graham, J.A, Lane,
A.P., Zealey, W.J.: 1986, As/ron. Astrophys.
Reipurth, B., Graham, J.A: 1988, Astron. Astrophys.
202, 219.
Scarrott, S. M., Wolstencroft, R 0.: 1988,
Monthly Notiees R. Astron. Soe. 231, 1019.
Schwartz, R.D., Henize, K. G.: 1983, Astrophys.
J. 88, 1665.
van den Bergh, S.: 1975, Publ. Astron. Soe.
Paeifie 87,405.
37-39 (PDF)
E. Bajaja, E. Hummel
Observation of the 12CO (J = 1→0) line in NGC 613 with the SEST.

ADS BibCode:
Bajaja, E.; Hummel, E.
AA(Max-Planck-Institut für Radioastronomie, Bonn, F.R. Germany) AB(University of Manchester, Nuffield Radio Astronomy Laboratories, Jodrell Bank, Macclesfield, Cheshire, U. K.)
The availability of the Swedish-ESO SUbmillimeter Telescope (SEST) on La Silla opened the possibility of extending the radio observation of molecular lines to the very southern galaxies. In particular the observation of the CO lines in the nearest galaxies will permit not only to increase the sampling for statistical purposes but also to study in more detail the distribution and kinematical properties of the molecular clouds in relation to other components of the galaxies. The HPBW of the SEST, at the frequency of 115 GHz of the 12CO (J = 1 -> 0) line, is 43" which means that galaxies with diameters between 5.5 and 10 minutes of arc are weil suited for mapping since they do not require a prohibitive amount of time and the arms can be resolved if the inclination angle is adequate.
Bajaja, E.: 1978, Publ. Dept. Astron. Universidad
de Chile, 111, 55.
Booth, R.S., Oe Jonge, M.J., Shaver, P.A.:
1987, The Messenger48, 2.
Burbidge, E.M., Surbidge, G.R., Rubin, V.C.,
Prendergast, K. H.: 1964, Astrophys. J.
Elmegreen, D.M., Elmegreen, B.G.: 1982,
Astron. J. 87, 626.
Hummel, E., Jörsäter, S., Lindblad, P.O.,
Sandquist, A.: 1987, Astron. Astrophys.
Reif, K., Mebold, U., Goss, W.M., van Woerden,
H., Siegman, S.: 1982, Astron. Astrophys.
Suppl. Sero 50, 451.
Vaucouleurs, G. de, Vaucouleurs, A. de, Corwin,
H.C.: 1976, Second Reference Catalogue
of Bright Galaxies, The University of
Texas Press, Austin.
39-41 (PDF)
R. Bandiera, P. Focardi
High resolution Hα spectroscopy of Nova Centauri 1986. Tracing a transient in the spectral evolution.

ADS BibCode:
Bandiera, R.; Focardi, P.
AA(Osservatorio Astrofisico di Arcetri, Firenze, Italia) AB(Dipartimento di Astronomia, Universita di Bologna, Italia)
We present here some preliminary results and considerations regarding high resolution spectroscopy of Nova Centauri 1986. This object was discovered on November 22.7 UT as a 5.6 V magnitude star (1), and observed by us in Ha two months later, when it was of about 10 magnitude. A considerable change in the Ha line profile, basically consisting in the disappearance of the original f1attop profile substituted by a more regular multicomponent profile, is clearly visible in our set of spectra, obtained monitoring the nova for nearly a week. A fitting of the line profile by means of three gaussian components shows a narrowing of the components and a rapid fading of one of them as a function of time. This behaviour can be interpreted in terms of blobs which have been formed in a non-spherical explosion and that were evaporating at the time of the observations.
(1) McNaught, RH. 1986, IAU Gire. N. 4274.
(2) Dekker, H., Delabre, B., D'Odorico, S.,
Lindgren, H., Maaswinkel, F., and Reiss,
R 1986, The Messenger43, 27.
(3) Gratton, RG., Focardi, P., and Bandiera,
R. 1989, M.N.RAS., submitted.
(4) Bandiera, R, Focardi, P., Altamore, A.,
Rossi, C. and Stahl, O. 1988 Physies of
Luminous Blue Variables, IAU Coll.
No. 113, in press.
(5) Mustel, E. R, and Boyarchuk, A.A. 1970,
Ap.Sp.Sei.6, 183.
(6) Hutchings, J.B. 1972, M.N.R.A.S. 158,
(7) McNaught, RH., Campos, J. 1987, lAU
eire. N. 4298.
(8) McNaught, RH., 1987, IAU Gire. N. 4315.
41-45 (PDF)
G. Mathys et al.
The European working group on chemically peculiar stars of the upper main sequence. The first 10 years.

ADS BibCode:
Mathys, G.; Maitzen, H. M.; North, P.; Hensberge, H.; Weiss, W. W.; Ansari, S.; Catalano, F. A.; Didelon, P.; Faraggiana, R.; Fuhrmann, K.; Gerbaldi, M.; Renson, P.; Schneider, H.
AA(Geneve) AB(Vienna) AC(Lausanne) AD(Brussels) AE(Vienna) AF(Vienna) AG(Catania) AH(Strasbourg) AI(Trieste) AJ(Göttingen) AK(Paris) AL(Liege) AM(Göttingen)
A fraction of the Band A type stars have chemical peculiarities (CP). 4 subgroups are recognized: CP 1 or Am, CP2 or magnetic Ap (with enhanced Sr, Cr, Eu, Si lines), CP3 (ar non-magnetic Ap, with Hg Mn enhanced) and CP4 (B type stars with He peculiarities, a fraction of them appear to be a hot extension of CP 2).
Abt, H.A.: 1979, Astrophys. J. 230, 485.
Baade, D., Weiss, W. W.: 1987, Astron. Astrophys.
Suppl. 67, 147.
Bidelman, W.P., MacConnell, D.J.: 1973, Astron.
J. 78, 687.
Catalano, F.A., Renson, P.: 1984, Astron.
Astrophys. Suppl. Sero 55, 371.
Catalano, F.A., Renson, P.: 1988, Astron.
Astrophys. Suppl. Sero 72, 1.
Didelon, P.: 1987, The Messenger49, 5.
Gerbaldi, M., Faraggiana, R.: 1986, Astron.
Maitzen, H. M.: 1976, Astron. Astrophys. 51,
Maitzen, H.M.: 1981, Astron. Astrophys. 96,
Maitzen, H. M., Schneider, H., Weiss, W. W.:
1988, Astron. Astrophys. Suppl. Sero 75,
Maitzen, H. M., Vogt, N.: 1983, Astron. Astrophys.
123, 48.
Manfroid, J., Mathys, G.: 1985, Astron. Astrophys.
Suppl. Sero 59, 429.
Manfroid, J., Mathys, G.: 1986, Astron. Astrophys.
Suppl. Sero 64, 9.
Mathys, G., Manfroid, J.: 1986, Astron. Astrophys.
Suppl. Sero 60, 17.
Mathys, G., Manfroid, J., Renson, P.: 1986,
Astron. Astrophys. Suppl. Sero 63, 403.
North, P.: 1984, Astron. Astrophys. Suppl.
Sero 55, 259.
North, P.: 1987, Astron. Astrophys. Suppl.
Sero 69, 371.
Robinson, R.D.: 1980, Astrophys. J. 239,
Schneider, H.: 1981 , Astron. Astrophys.
Suppl. Sero 44, 137.
Schneider, H.: 1986, "Upper Main Sequence
Stars with Anomalous Abundances", IAUColl.
No. 90, eds. C. R. Cowley et al. ,
Schneider, H.: 1987, Hvar Obs. Bull. 11,29.
Schneider, H., Weiss, W. W.: 1986, Mon. Not.
Roy. Astr. Soc. 215, 77.
Schneider, H., Weiss, W.W.: 1989, Astron.
Astrophys., in press.
Weiss, W. W., Kreidl, T. J.: 1980, Astron. Astrophys.
81, 59.
Weiss, W. W., Schneider, H.: 1984, Astron.
Astrophys. 135, 148.
Waelkens, Ch., Rufener, F.: 1985, Astron.
Astrophys. 152, 6.
45-47 (PDF)
J. Andersen et al.
AK Scorpii: a new pre-main-sequence spectroscopic binary.

ADS BibCode:
Andersen, J.; Lindgren, H.; Hazen, M. L.; Mayor, M.
AA(Copenhagen University Observatory, Denmark, AND Center for Astrophysics, Cambridge, Mass., USA) AB(ESO) AC(Center for Astrophysics, Cambridge, Mass., USA) AD(Observatoire de Geneve, Switzerland)
While we know that perhaps - 25% of normal main-sequence stars are spectroscopic binaries, very few of their Progenitor systems have yet been detected among (low-mass) pre-main-sequence stars: Mathieu's (1988) review at the recent IAU General Assembly lists only 11, and for only three had orbits been published at that time. This meagre yield must be due mainly to selection effects mitigating against the discovery of pre-main-sequence binaries. These stars are intrinsically faint and generally found in highly obscured regions, so systematic and accurate radial-velocity observations were impossible until the advent of efficient cross-correlation techniques. Oue to their importance for the understanding of star formation processes in general, pre-main-sequence binaries are now being searched for very actively, and the sampie will no doubt increase sharply over the next few years. We would like
Herbig, G.H., Raa, N.K.: 1972, Astrophys. J.
Kilkenny, D., et al.: 1985, South Afr. Astron.
Obs. Cire. No. 9, 55.
Mathieu, R.D.: 1988, Highlights of Astronomy,
Val. 8, in press.
Popper, D. M.: 1980, Ann. Rev. Astron. Astrophys.
18, 115.
Walter, F.M., et al.: 1988, Astron. J., 96, 297.
47-49 (PDF)
B. M. Shustov
Supershells and galactic fountains.

ADS BibCode:
Shustov, B. M.
AA(Astronomical Council, Moscow, USSR)
In the gaseous disk of our Galaxy as well as in other galaxies, HI structures (shells, bubbles, holes, etc.) on scales of 0.1-1 kpc are recognized to be common features; see e.g. the comprehensive review by Tenorio-Tagle and Bodenheimer (1988). The larger ones are usually named with the prefix "super". The estimated energies which are required to produee sueh large objeets are high - up to some 1054 erg. These energetic events must exert a significant influenee upon the gaseous galactic disk and eorona.
Ambarzumian, V.A.: 1947, Stellar Evolution
and Astrophysics., Armenian Aead. Sei.
Blaauw, A.: 1964, Ann. Rev. Astron. Astrophys.
2, 213.
Bregman, J.N.: 1980, Astrophys. J. 236, 577.
Corbelli, E., Salpeter, E. E.: 1988, Astrophys.
J. 326, 551.
Cox, D. P., Smith, B. W.: 1974, Astrophys. J.
(Letters) 189, L 105.
Hulbosh, A.N.M., Wakker, B.P.: 1988, Astron.
and Astrophys. Suppl. 75, 191.
Igumentshehev, I. V., Tutukov, A. V., Shustov,
B. M.: 1988, Astron. Zirkular N 1532, 21.
Igumentshchev, I. V., Tutukov, A. V., Shustov,
B. M.: 1989, Astron. Zh. (in press).
McKee, C. F., Cowie L. L.: 1977, Astrophys. J.
Shapiro, P. R., Field, G. B.: 1976, Astrophys.
J. 205, 762.
Tenorio-Tagle, G., Bodenheimer, P.: 1988,
Ann. Rev. Astron. Astrophys. 26, 145.
Weaver, R., MeCray, R., Castor, J., Shapiro,
P., Moore, R.: 1977, Astrophys. J. 218,
49-50 (PDF)
F. Paresce
Searching for light echoes from circumstellar dust shells around SN 1987A.

ADS BibCode:
Paresce, F.
AA(Space Telescope Science Institute, Baltimore, Maryland, USA, AND Astrophysics Division, Space Science Department of ESA)
The Space Telescope Science Institute coronograph (described in the Messenger, 47, p.43) mounted on the 2.2-m telescope at La Silla was used by myself and my colleague Chris Burrows to look for light echos in the immediate vicinity of the SN 1987A in the LMC. This technique allows us to probe circumstellar regions from about 2 to 20 arcseconds in the vicinity of very bright objects such as the SN 1987A for faint features otherwise completely lost in their glare.
51-51 (PDF)
G. Burki et al.
The Geneva photometric monitoring of SN 1987A.

ADS BibCode:
Burki, G.; Cramer, N.; Burnet, M.; Rufener, F.; Pernier, B.; Richard, C.
AA(Geneva Observatory, Switzerland) AB(Geneva Observatory, Switzerland) AC(Geneva Observatory, Switzerland) AD(Geneva Observatory, Switzerland) AE(Geneva Observatory, Switzerland) AF(Geneva Observatory, Switzerland)
A systematie photometrie monitoring of SN 1987A has been earried out from the Swiss station at the ESO La Silla Observatory (Chile), by using a 70-em teleseope equipped with the P7 photometer (Burnet and Rufener, 1979), devoted to the Geneva 7-eolour photometric system. The supernova has been measured 463 t;mes fram Feb. 24, 1987, to Jan. 17, 1989 (see Burki et al., 1989).
Arnett, W. D.: 1988, Theoretical models of
supernova 1987A, in Supernova 1987A in
the LMC, eds. M. Kafatos and A. Michalitsianos,
Cambridge University Press, Cambridge,
p. 301.
Burki, G., Cramer, N., Burnet, M., Rufener, F.,
Pernier, B., Richard, C.: 1989, Astron. Astrophys.
Letter, in press.
Burnet, M., Rufener, F.: 1979, Astron. Astrophys.
74, 54.
Nomoto, K., Shigeyama, T., Kumagai, S.,
Itoh, M., Nishimura, J., Hashimoto, M.,
Saio, H., Kato, M.: 1988, to appear in
Physics of Neutron Stars and Black Holes,
ed. Y. Tanaka, Universal Academy Press,
Tokyo, p. 441.
Woosley, S.E., Pinto, P.A., Hartmann, D.:
1989, Astrophys. J., submitted.
52-55 (PDF)
H. Butcher, T. Schoenmaker
Squeezing the most from the CES.

ADS BibCode:
Butcher, H.; Schoenmaker, T.
AA(Kapteyn Observatory, Roden, the Netherlands) AB(Kapteyn Observatory, Roden, the Netherlands)
In the Messenger No. 51 (p. 12-15), an attempt to use the GES for radioactive chronometry of the Galaxy was described. Two instrumental aspects of the observations were noted as being not yet under adequate control: (i) The determination in detail of the instrumental profile, the wings of which cannot be determined weil, except at laser line wavelengths, and the shape of which is found to depend on the often variable focus across the array detector format, and at least sometimes on the signal level in the detector used. (ii) The markedly asymmetrical distribution of the noise from the Reticon detector (caused by energetic particle detections) for low flux levels and integrations of an hour and longer. Treatment of the data in an optimum way is problematical due to these effects, and although the CES remains one of the world's best instruments of its type, study of such deficiencies can be expected to improve its Performance significantly.
52-52 (PDF)
Is there a pulsar in supernova 1987A ?

ADS BibCode:
A recent announcement of the discovery of a pulsar in Supernova 1987 A in the Large Magellanic Gloud has excited the world-wide astronomical community. New observations at the La Silla Observatory by a group of European astronomers1 from the Max Planck Institute for Extraterrestrial Physics and the European Southern Observatory, however, do not confirm the reality of this object. More observations are now needed to settle this important question.
55-59 (PDF)
G. Meylan et al.
What is the mass-to-light ratio of the old Magellanic globular cluster NGC 1835?

ADS BibCode:
Meylan, G.; Dubath, P.; Mayor, M.; Magain, P.
AA(ESO) AB(Observatoire de Geneve, Switzerland) AC(Observatoire de Geneve, Switzerland) AD(Institut d'Astrophysique de Liege, Belgium)
We astronomers are lucky: our Galaxy as two companion galaxies, the Large and Small Magellanic Clouds, situated weil above the galactic plane, which Contain a huge potential of astrophysical information. For example, concern: ng star clusters, the realm of the globuar clusters is much richer and more Varied in the Magellanic Clouds than in the Galaxy: rich clusters of all ages are observed, from the youngest, having ages of a few tens 10^6 yr to the oldest 1haV'lng ages of the order"or larger than 10 10^9 yr. In this paper, only old Magellanic and galactic globular clusters are considered.
Baranne, A., Mayor, M., and Poncet, J. L.
1979, Vistas in Astronomy, 23, 279.
Ghun, M.S. 1978, Astron. J., 83, 1062.
Elson, R.A.W., and Freeman, K.G. 1985, Astrophys.
J., 288, 521.
Freeman, K.G. 1974 ESO/SRG/CERN Conference
on Research Prog. for the New
Large Telesc. Geneva p. 177.
Griffin, R. F. 1967, Astrophys. J., 148, 465.
Gunn, J. E., and Griffin, R. F. 1979, Astron. J.,
Lupton, R., Gunn, J. E., and Griffin, R. F. 1985 Dynamics of Stars Clusters IAU Symp·
113, Princeton 1984, Edit. J. Goodman
and P. Hut, p. 19.
Lupton, R., Gunn, J. E., and Griffin, R. F.
1987, Astran. J, 93, 1114.
Mateo, M. 1987 Ph. D. Thesis University of
Meylan, G. 1987, Astron. Astrophys., 184,
Meylan, G. 1988a, Astron. Astrophys., 191,
Meylan, G. 1988b, Astrophys. J. 331, 718.
Meylan, G. 1989, Astron. Astrophys. in press.
Pryor, C., McClure, R.D., Fletcher, J. M.,
Hartwiek, F.D.A., and Kormendy, J. 1986,
Astron. J, 91, 546.
59-60 (PDF)
H. Barwig
High-tech telescope on top of Mount Wendelstein.

ADS BibCode:
Barwig, H.
AA(Universitäts-Sternwarte München, F. R. Germany)
A prominent feature of the silhouette of the Alps, tl1e Wendelstein Mountain, can be seen from Garching on clear days. Extremely transparent skies sometimes even allow one to recognize On top of that mountain the domes of lhe Observatory of the University of Munich (USM). Only 75 km away, after One hour's ride, this site can easily be reached via cable car or by means of a famous 75-year-old cog railroad. Final access to the very top is achieved by an elevator climbing up 114 m within the mountain.
60-61 (PDF)
E. Giraud
Spatial resolution imaging of the radio source 3C 255.

ADS BibCode:
Giraud, E.
The optical identifications of the 3CR sources are now nearly complete (Spinrad et al. 1988), and only 7 are lacking redshifts. The radio source 3C 255 is one of these remaining sources, and the deep image presented here was taken to search for a possible underlying distant cluster. Three CCO exposures in V and R were taken with the 2.2-m ESO-MPI telescope on La Silla under moderately good seeing conditions (1.2 to 1.5 arcsec). Adding these images gives a total exposure time of 2 h. The visible counterpart of the radio source is the central object of the frame. There are three other objects, W, E, and S, located at about 7 arcsec from it.
Gunn et al., 1986, Ap. J., 306, 30.
Le Fevre and Hammer, 1988, Ap. J. Letters,
333, L37.
Mac Carthy et al., 1987, Ap. J. Letters, 319,
Spinrad et al., 1988, A. J., 96, 836.
61-62 (PDF)
R. Haefner
The spectacular binary system PG 1550+131.

ADS BibCode:
Haefner, R.
AA(Universitäts-Sternwarte, München, F. R. Germany)
PG 1550+ 131 was known as a faint, very blue object (V = 16.8, U-B =-1.2) in the constellation Ophiuchus. Its optical Spectrum showed the Balmer lines and the Balmer jump in emission. Scarce Photometric data indicated large amPlitude variations. So it seemed to be a relatively uninteresting member of the cataclysmic variables, not deserving further detailed observational attention. Nevertheless, it was included in a programme to search for eclipsing, faint Cataclysmic variables and aiming at the determination of primary masses in such systems. The observations were performed using the CCD camera at the Oanish 1.5-m telescope at La Silla. PG 1550+ 131 turned then out to be the most spectacular eclipsing system found during this survey.
62-64 (PDF)
G. Avila et al.
Report on the last observing run of multiobject spectroscopy. OPTOPUS is alive and kicking.

ADS BibCode:
Avila, G.; D'Odorico, S.; Tarenghi, M.; Guzzo, L.
AA(ESO) AB(ESO) AC(ESO) AD(Osservatorio Astronomico di Brera, Milano, Italy)
The ESO fibre facility for multiobject spectroscopy at the Cassegrain focus of the 3.6-m telescope, OPTOPUS, has been operating since March 1985. A complete description of the system is given in the ESO Operating Manual No. 6. It is possible to observe with OPTOPUS a maximum of 52 objects distributed over a field of 33'. Special aperture plates are prepared in advance of the observations in the ESO workshop from accurate alpha and delta coordinates of the selected objects. These plates are eventually mounted at the telescope and the fibres are manually inserted in the apertures; at the other end they form the entrance slit of a CCD spectrograph. In the last four years OPTOPUS has been used in 33 nights for 14 different programmes. It has always operated with high reliability, collecting some 6,000 spectra. The limiting magnitudes at a resolving power of about 500 in the visual are about 18.5 for galaxies and 20 for quasars in a two-hour exposure. While these limits allow useful work for a large number of programmes, there are two aspects of the present system which must be considered as unsatisfactory: the poor blue-UV transmission of the fibres and the reduced efficiency of a number of them, mainly due to imperfect centring of the microienses at their input ends. As the interest in using the facility is actually increasing (see e.g., DAEC Workshop, 1988), ESO started a programme to improve the weak points while keeping the basic conceptunchanged.
Avila, G. and D'Odorico, S.: 1988, Proceed"
ings of the ESO Conference on Very Large
Telescopes and their Instrumentation,
M. H. Ulrich editor, p. 1121.
Avila, G.: 1988, ASP Conference Series, S.G.
Barden editor, Vol. 3, p. 63.
DAEC Workshop, 1988, "Large Scale Struc"
tures: Observations and Instrumentation",
Proceedings edited by C. Balkowski and S.
Geiler, M.J., de Lapparent, V., and Huchra,
J., 1988: in "Large Scale Structures in the
Universe", IAU Symp. 130, J. Audouze and
A. Szalay eds., Dordrecht, Reide!.
Giovanelli, R., Haynes, M. P., 1988: in "Large
Scale Structures in the Universe", IAU
Symp. 130, J. Audouze and A. Szalay eds.,
Dordrecht, Reide!.
Heydon-Dumbleton, N.H., Collins, G.A., and
MacGillivray, H. T., 1989: M.N.R.A.S., sub"
Hili, J. M., Lasser, M. P.: 1986, SPIE 627, 303.
Parry, I.A., Gray, P.M.: 1986, SPIE627, 118.
Rood, H.J., 1988: Ann. Rev. Astron. Astro"
phys. 26, 245.
64-65 (PDF)
H. Dekker
Optics and grisms of EFOSC2.

ADS BibCode:
Dekker, H.
In the Messenger No. 52 the construction of a second EFOSC for the 2.2-m telescope was announced. Mechanically, EFOSC2 is virtually a copy of EFOSC but comparison of the optical data (see Table 1) shows considerable differences which for some programmes will make EFOSC2 the preferred instrument, even if it is mounted on a smaller telescope.
65-66 (PDF)
ESO Image Processing Group: MIDAS Memo

ADS BibCode:
Now that system developments in the portable version of MIDAS have stabilized, activities in the area of applications have resumed. The echelle package is being upgraded to minimize the number of parameters controlling the reduction sequence, and to correct some known deficiencies of the current version. The new package will also be optimized to process data from other instruments like EFOSC and Echelec.
66-67 (PDF)
D. Chittim
Ethernet at ESO Headquarters.

ADS BibCode:
Chittim, D.
AA(Benney Electronics, ESO)
Ethernet is a cable used with associated software packages for connecting computer equipment throughout a building. It has the advantage that equipment can be connected along its length at almost any point. Due to the high data transmission speeds involved, ethernet is most suitable for computer-to-computer communications although terminals can be connected onto it if necessary.
68-68 (PDF)
S. D'Odorico
A Slice of Swiss Cheese Made Out of Steel

ADS BibCode:
D'Odorico, S.
A Slice of Swiss Cheese Made Out of Steel