ESPRESSO

View previous topic View next topic Go down

ESPRESSO

Post by Borislav on 28th October 2009, 7:04 am

http://espresso.astro.up.pt/science.php?show=chapter5

5.1 Distribution of GTO time among science cases

The Consortium has agreed to conduct the different GTO programs as a common effort, with the following distribution of GTO time among science cases:


  • 80% for low-mass extrasolar planets
  • 10% for fundamental constants
  • 10% for other, high-quality science to be determined at a later stage of the project


In the following sections it is assumed that the Consortium will receive about 160-240 VLT nights depending on the total investment (1 VLT night = 50 kEUR). This would represent about 1500 hours of observing time for extrasolar planets and 200 hours for fundamental constants. The use of this observing time is described in more details below for the two major science cases.


5.2.1 Main scientific objectives
The exoplanet GTO program will consist of a survey of a carefully selected sample of nearby GKM dwarfs with the goal to detect a significant fraction of the planets orbiting them within ~1 AU down to minimum masses of ~1-2 Mearth. Some of these objects will be located in the habitable zone.


5.2.2 Number of potential targets
For GK dwarfs we aim at 10 cm/s accuracy with ESPRESSO in 1-UT mode. According to the expected instrumental performances, we will focus on bright stars with V < 8.5, for which a RV precision of ~5-10 cm/s can be obtained in 15-30 minutes of integration time. Such an exposure time is also needed to average out the stellar noise (p-mode oscillations and granulation).
We will use the results from the HARPS GTO surveys and carry out dedicated programs with this instrument to establish the best possible list of targets. A search in the Hipparcos catalogue, selecting mid-G to mid-K dwarfs observable from Paranal with visual magnitudes brighter than 8.5, gives a total of more than 1000 stars. We then need to exclude spectroscopic binaries and active stars. In fact, we need the most inactive stars of the solar neighbourhood. These will be known from the HARPS GTO programs. Depending on the exact selection criteria, a list of at least 100-200 suitable G and K stars can be obtained.
Regarding the M targets, there are over 30 nearby M0.5-M4.5 stars brighter than V=12 mag and with declination < 10 deg, for which ESPRESSO can provide spectra with an accuracy better than 40 cm/s in one hour integration time or less. Note that this accuracy is enough to detect rocky planets in the habitable zones of Ms. These stars are single or very wide binaries, and most of them are also in the HARPS GTO sample. This will allow us to optimally select the best targets to follow with ESPRESSO.


5.2.3 Observing strategy

A trade-off has to be performed between the number of targets in the sample and the number of measurements on each target. The experience acquired with HARPS tends to stress the importance of accumulating a lot of measurements per star rather than observing a lot of stars, for two main reasons: 1) complex multi-planet systems are common and require many measurements to be resolved, and 2) the fraction of stars having low-mass planets seems to be high (at least 30% according to the most recent HARPS results), and therefore meaningful statistics can be obtained even with a relatively small sample.
Although the best observing strategy will be studied in mode detail during later stages of the project, we can for the moment assume an average number of 40-50 measurements per star and 15-30 min of integration time per measurement. Obviously, the number of measurements per target will be adjusted according to the characteristics of the RV signals emerging from the data. With this strategy we can estimate how many stars can be observed during GTO time: 1500 hours / 15 hours per star = 100 stars. This number is well within the expected number of available targets. At first glance, 100 stars may appear somewhat low to obtain useful statistical properties of low-mass extrasolar planets. However, if we assume that 50% of the stars do have such planets, and that they always come in multi-planet systems with an average of 2-3 detectable planets per system, this would already give us about 100-150 planets. This is enough to reach the scientific goals mentioned above, although further refinements will require more observing time.
The exoplanet GTO program can be carried out over a time span of about 3 years, but a longer duration would be also acceptable. Distributed over 3 years, it would represent about 25 nights per semester.

http://espresso.astro.up.pt/
The astronomical community and ESO have recognized that a new HARPS for the VLT is necessary to push the detection limits down to Earth- like planets. ESO’s Scientific Technical Committee recommended to ESO, in October 2007, to initiate as soon as possible the Call for Proposal for a High-Resolution Ultra-Stable Spectrograph for the VLT called ESPRESSO. The ESPRESSO Consortium, composed of institutes from various European countries, has answered to ESO’s call for a Phase A study and was successfully selected for this task in Autumn 2008. Phase A started in January 2009 and will last until end 2009. If approved by ESO, the project will continue with Phase B starting in 2010 and last for about 4 years. Installation and commissioning of ESPRESSO at the VLT is foreseen in 2014.

Borislav
Jovian
Jovian

Number of posts : 556
Registration date : 2008-11-12

View user profile

Back to top Go down

Re: ESPRESSO

Post by Sirius_Alpha on 28th October 2009, 8:37 am

Wow, an impressive read. So EXPRESSO will be better than HARPS?

_________________
Caps Lock: Cruise control for 'Cool'!
avatar
Sirius_Alpha
Admin
Admin

Number of posts : 3468
Location : Earth
Registration date : 2008-04-06

View user profile http://solar-flux.forumandco.com/

Back to top Go down

Re: ESPRESSO

Post by Borislav on 28th October 2009, 9:13 am

Sirius_Alpha wrote:Wow, an impressive read. So EXPRESSO will be better than HARPS?

This is future SuperHARPS Geneva group. Began work in 2014.

Borislav
Jovian
Jovian

Number of posts : 556
Registration date : 2008-11-12

View user profile

Back to top Go down

Re: ESPRESSO

Post by Sirius_Alpha on 28th October 2009, 9:36 am

Wow. SuperHARPS?
Searched SuperHARPS and found some references to it being placed on VLT, as well as the Giant Magellan Telescope. Which is to be the location of SuperHARPS?

_________________
Caps Lock: Cruise control for 'Cool'!
avatar
Sirius_Alpha
Admin
Admin

Number of posts : 3468
Location : Earth
Registration date : 2008-04-06

View user profile http://solar-flux.forumandco.com/

Back to top Go down

Re: ESPRESSO

Post by exoplanet on 28th October 2009, 9:54 am

ESPRESSO will achieve a precision of 0.1m/s while, currently, HARPS delivers 0.97m/s. So a ten-fold increase in precision.

exoplanet
Planetesimal
Planetesimal

Number of posts : 124
Location : here
Registration date : 2008-06-16

View user profile

Back to top Go down

Re: ESPRESSO

Post by Borislav on 28th October 2009, 10:07 am

Sirius_Alpha wrote:Wow. SuperHARPS?
Searched SuperHARPS and found some references to it being placed on VLT, as well as the Giant Magellan Telescope. Which is to be the location of SuperHARPS?

"SuperHARPS" my synonym ESPRESSO. ESPRESSO in VLT.

http://www.shao.ac.cn/bdep_meeting/download/talks/20July/10-LPasquini.ppt

We are developing a vigorous Precise Radial Velocity Programme Which in the next years will allow (numbers refer to G2V star):

Rocky Planets around stars as faint as V ~ 9
(ESPRESSO @ VLT in 1 UT mode) (2014)

Neptune mass planets around stars as faint as V ~ 12
(ESPRESSO @ VLT in 4 UT mode ) (2014)

Earth-like planets around stars as faint as V ~ 9
(CODEX @ ELT ) (2017) .. And of course heavier planets around
much fainter objects

Borislav
Jovian
Jovian

Number of posts : 556
Registration date : 2008-11-12

View user profile

Back to top Go down

Re: ESPRESSO

Post by Led_Zep on 7th August 2013, 7:54 pm

http://www.eso.org/public/announcements/ann13065/

ESPRESSO (Echelle SPectrograph for Rocky Exoplanet and Stable Spectroscopic Observations) is an ultra-stable spectrograph that will be installed at ESO’s Paranal Observatory in Chile in 2016. It will be capable of combining light from all four Unit Telescopes of the Very Large Telescope (VLT) to create a virtual 16-metre aperture telescope.
ESPRESSO is expected to allow astronomers to detect Earth-like planets around nearby stars using the radial velocity method.
avatar
Led_Zep
Jovian
Jovian

Number of posts : 517
Location : France
Registration date : 2011-09-09

View user profile

Back to top Go down

Re: ESPRESSO

Post by Lazarus on 24th January 2014, 5:48 pm

Another article on the plans for ESPRESSO and the potential scientific applications (which are not just limited to exoplanets)

ESPRESSO: The next European exoplanet hunter
http://arxiv.org/abs/1401.5918

The project passed the final design review in May 2013 and entered the manufacturing phase. ESPRESSO will be installed at the Paranal Observatory in 2016 and its operation is planned to start by the end of the same year.
avatar
Lazarus
dG star
dG star

Number of posts : 2819
Registration date : 2008-06-12

View user profile

Back to top Go down

Re: ESPRESSO

Post by Led_Zep on 19th October 2016, 10:39 am

http://www.eso.org/public/france/announcements/ann16073/

ESPRESSO Sees Light at the End of the Tunnel
First big step towards adding a new high-resolution spectrograph to the VLT
avatar
Led_Zep
Jovian
Jovian

Number of posts : 517
Location : France
Registration date : 2011-09-09

View user profile

Back to top Go down

Re: ESPRESSO

Post by Sponsored content


Sponsored content


Back to top Go down

View previous topic View next topic Back to top


 
Permissions in this forum:
You cannot reply to topics in this forum