Hubble image of LRLL 54361 and its surroundings
Hubble image of LRLL 54361
How LRLL 54361 flashes like a strobe light
Videos
Light echoes from LRLL 54361 (annotated)
The NASA/ESA Hubble Space Telescope has
produced a time-lapse movie of a mysterious protostar that behaves like a
flashing light. Every 25.34 days, the object, designated LRLL 54361,
unleashes a burst of light which propagates through the surrounding dust
and gas. This is only the third time this phenomenon has been observed,
and it is the most powerful such beacon seen to date. It is also the
first to be seen associated with a light echo.
The cause of the fireworks seen in this Hubble image and video is
hidden behind a dense disc and envelope of dust. However, astronomers
think that the strobe effect is due to periodic interactions between two
newly-formed stars that are gravitationally bound to each other.
These two stars drag material inwards from a surrounding disc of gas
and dust. Astronomers propose that the light flashes seen in this video
are due to this material suddenly being dumped onto the growing stars as
they near one another in their orbits, unleashing a blast of radiation.
“The protostar has such large brightness variations with a precise period that it is very difficult to explain,”
says James Muzerolle of the Space Telescope Science Institute in
Baltimore, USA, who has recently studied this fascinating object using
Hubble and NASA’s Spitzer Space Telescope. Spitzer made repeated
observations over seven years, before Hubble was pointed towards the
object to make detailed observations over the period of one pulse event.
The Hubble observations uncover a spectacular movement of light away
from the centre of the system, an optical illusion known as a light
echo. While it might look like eruptions of gas are coming out of the
protostar, these pulses are actually flashes of light propagating
through the surrounding dust and gas and reflecting towards the
observer: there is no substantial physical motion within the cloud over
these timescales.
Flashing double star systems like this one are rare, because close
binaries account for only a few percent of our galaxy’s stellar
population. Moreover, the pulsing light is likely to be a brief
phenomenon in the early life of a star.
Notes
The Hubble Space Telescope is a project of international cooperation between ESA and NASA.
Image credit: NASA, ESA, J. Muzerolle (STScI)
Links
- Images of Hubble
- A press release from NASA, with more information about scientific research into LRLL 54361 is available here
Contacts
Oli Usher
Hubble/ESA
Garching, Germany
Tel: +49-89-3200-6855
Email: ousher@eso.org
Hubble/ESA
Garching, Germany
Tel: +49-89-3200-6855
Email: ousher@eso.org
James Muzerolle
Space Telescope Science Institute
Baltimore, USA
Tel: +1-410-338-4719
Email: muzerol@stsci.edu
Space Telescope Science Institute
Baltimore, USA
Tel: +1-410-338-4719
Email: muzerol@stsci.edu
Ray Villard
Space Telescope Science Institute
Baltimore, USA
Tel: +1-410-338-4514
Email: villard@stsci.edu
Space Telescope Science Institute
Baltimore, USA
Tel: +1-410-338-4514
Email: villard@stsci.edu
