The location of the Lupus 4 dark cloud in the constellation of Lupus
Wide-field view of the sky around the dark cloud Lupus 4
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Lupus 4, a spider-shaped blob of gas and
dust, blots out background stars like a dark cloud on a moonless night
in this intriguing new image. Although gloomy for now, dense pockets of
material within clouds such as Lupus 4 are where new stars form and
where they will later burst into radiant life. The Wide Field Imager on
the MPG/ESO 2.2-metre telescope at ESO’s La Silla Observatory in Chile
captured this new picture.
Lupus 4 is located about 400 light-years away from Earth,
straddling the constellations of Lupus (The Wolf) and Norma (The
Carpenter's Square). The cloud is one of several affiliated dark clouds
found in a loose star cluster called the Scorpius–Centaurus OB association. An OB association is a relatively young, yet widely dispersed grouping of stars [1]. The stars likely had a common origin in a gigantic cloud of material.
American astronomer Edward Emerson Barnard is credited with
the earliest descriptions of the Lupus dark clouds in the astronomical
literature, back in 1927. Lupus 3, neighbour to Lupus 4, is the best
studied, thanks to the presence of at least 40 fledgling stars formed
over the last three million years, and which are on the cusp of igniting
their fusion furnaces (eso1303).
The main energy source in these adolescent stars, known as T Tauri
stars, is the heat generated by their gravitational contraction. That is
in contrast to the fusion of hydrogen and other elements which powers
mature stars such as the Sun.
Observations of the cold darkness of Lupus 4 have turned up only a few T Tauri stars.
Yet promisingly for Lupus 4 in terms of future star formation is a
dense, starless core of material in the cloud. Given a few million
years, that core should develop into T Tauri stars. Comparing Lupus 3
and Lupus 4 in this way suggests that the former is older than the
latter, because its contents have had more time to develop into stars.
How many stars might eventually start to shine within Lupus 4? It is
hard to say, as mass estimates for Lupus 4 vary. Two studies agree on a
figure of around 250 times the mass of the Sun, though another, using a
different method, arrives at a figure of around 1600 solar masses.
Either way, the cloud contains ample material to give rise to plenty of
bright new stars. Rather as earthly clouds make way for sunshine, so,
too, shall this cosmic dark cloud eventually dissipate and give way to
brilliant starlight.
Notes
[1] The "OB" refers to the
hot, bright, short-lived stars of spectral types O and B that are still
shining brilliantly within the widely dispersed cluster as it travels
through the Milky Way galaxy.
More information
ESO is the foremost intergovernmental
astronomy organisation in Europe and the world’s most productive
ground-based astronomical observatory by far. It is supported by 15
countries: Austria, Belgium, Brazil, the Czech Republic, Denmark,
France, Finland, Germany, Italy, the Netherlands, Portugal, Spain,
Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious
programme focused on the design, construction and operation of powerful
ground-based observing facilities enabling astronomers to make
important scientific discoveries. ESO also plays a leading role in
promoting and organising cooperation in astronomical research. ESO
operates three unique world-class observing sites in Chile: La Silla,
Paranal and Chajnantor. At Paranal, ESO operates the Very Large
Telescope, the world’s most advanced visible-light astronomical
observatory and two survey telescopes. VISTA works in the infrared and
is the world’s largest survey telescope and the VLT Survey Telescope is
the largest telescope designed to exclusively survey the skies in
visible light. ESO is the European partner of a revolutionary
astronomical telescope ALMA, the largest astronomical project in
existence. ESO is currently planning the 39-metre European Extremely
Large optical/near-infrared Telescope, the E-ELT, which will become “the
world’s biggest eye on the sky”.
Links
- Photos of the MPG/ESO 2.2-metre telescope
- Other photos taken with the MPG/ESO 2.2-metre telescope
- Photos of La Silla
Contacts
Richard Hook
ESO education and Public Outreach Department
Garching bei München, Germany
Tel: +49 89 3200 6655
Cell: +49 151 1537 3591
Email: rhook@eso.org
