Note: many of the images are displayed as small gifs to speed up
display: click on these images to see the full size image
Below are set of images that show our on sky progress with cirsi.
Many of the images have only undergone basic 'at telescope'
data reduction.
Some
image show various artifacts that will be removed by further
data processing such as better dark subraction and linear pattern noise
filtering and geometric rectification.
INT June 98 run
CIRSI image of the Galactic Centre
On the left is 10 minute exposure with CIRSI on the 2.5m Isaac Newton
Telescope,
in the H(1.65micron) waveband of a the region of sky
in the direction of the centre of the Milky Way, the so called
Galactic Centre. Each white dot is an star like the Sun. The clump
of objects just bottom left of centre is a densely packed cluster of
of millions stars believed to be located at the centre of the Milky Way.
Bottom right of centre is a another cluster of stars near the
galactic centre. These two clusters are about 30 light years
apart. The seeing on this image is 0.9".
On the right is an optical image of the same region of sky. The optical
image is quite different from the Infra-Red. The main difference is
that the Infra-red image has about 100 times more detected stars.
Dark matter and low mass stars
Stars like the Sun are not the commonest type of star in the
Universe. In fact most of the mass in the Universe is believed
to be contained in low mass stars that are much cooler than the
Sun. These cool stars are very faint in the optical but are much
brighter in the infra-red. However, one cannot measure the
mass of a star by observing how bright it is. One project that
we are tackling with CIRSI is a program to directly
determine the masses of low mass stars by searching for stars
that are eclipsing binaries.
The figure below shows two images of the star cluster NGC6633. These
images were obtained on the nights of June 15th 1998 and
June 17th 1998. The aim is to compare the two images
and look for stars that have changed in brightness between
the dates.
CIRSI images of the star cluster NGC6633. One image
was taken on the night of June 15th 1998 and the other
was taken on the night of June 17th 1998. The aim
is to use this data to seach for star that have changed
in brightness,
due the passage of an unseen companion like a planet or very
low mass star,
in front of the stellar disk. By determining the orbital
period and radial velocities of these binary stars we can make
a direct measurement of their masses using Newtons' laws
of gravitation.
Messier 16
Images of Messier 16 in the optical and Infrared. Messier 16 is a
cloud of gas and dust like Orion, within which stars are currently
forming. Messier 16 lies at a distance of around 7,000 light years
from the Earth. In astronomical terms Messier 16 is quite young,
with an age of a mere 5.5 Million years. In the optical we can only
see a few of the stars that lie in this young stellar nursery. Using
CIRSI can see right inside this dusty cloud.
CIRSI images of the star cluster NGC6633. One image
was taken on the night of June 15th 1998 and the other
was taken on the night of June 17th 1998. The aim
is to use this data to seach for star that have changed
in brightness,
due the passage of an unseen companion like a planet or very
low mass star,
in front of the stellar disk. By determining the orbital
period and radial velocities of these binary stars we can make
a direct measurement of their masses using Newtons' laws
of gravitation.
