An echelle spectrograph for precise radial velocity measurements in the near IR

Author(s):  
A. Berdja ◽  
L. Vanzi ◽  
A. Jordán ◽  
S. Koshida
1999 ◽  
Vol 170 ◽  
pp. 63-67
Author(s):  
I. V. Ilyin ◽  
R. Duemmler

AbstractWe briefly describe the instrumental effects which affect the accuracy of the radial velocity measurements. We have implemented several methods to correct for the instability effects and improve the accuracy of the measurements. These include modifications of the observational strategy and a time-dependent wavelength solution as well as a discussion of the error of the offset from cross-correlation. These methods are applied to observations obtained with the high resolution échelle spectrograph SOFIN mounted at the Cassegrain focus of the alt-azimuth 2.56-m Nordic Optical Telescope, La Palma, Canary Islands.


1999 ◽  
Vol 170 ◽  
pp. 29-35
Author(s):  
John Hearnshaw ◽  
Norman Rumsey ◽  
Garry Nankivell

AbstractA new fiber-fed échelle spectrograph (Hercules) is being designed for the 1-m telescope at Mt John University Observatory. The goals are to have a wavelength capability of 380 to 880 nm, covered in a single exposure on a 50-mm square CCD, to have a choice of resolving powers of 35000 or 70000 and to have no moving parts. High precision radialvelocity observations are a major but not the only goal. Designs with both R2 (blaze angle 63.4 deg) and R4 (blaze angle 76 deg) échelle gratings are being considered, in either case with a dimension of 408 mm perpendicular to the grooves.


2017 ◽  
Vol 47 (2) ◽  
pp. 195-201
Author(s):  
Sireesha Chamarthi ◽  
Ravinder K. Banyal ◽  
S. Sriram ◽  
Gajendra Pandey

1999 ◽  
Vol 170 ◽  
pp. 68-72 ◽  
Author(s):  
I. V. Ilyin ◽  
R. Duemmler

AbstractWe present our measurements of radial velocities of two stars suspected to have a substellar companion by using observations made with a cassegrain échelle spectrograph. The stability issues and details of the data reduction are discussed in Ilyin & Duemmler (paper I, these proceedings). The results obtained here show that relatively high accuracy of radial velocity determinations is also attainable for cassegrain spectrographs.


1991 ◽  
Vol 148 ◽  
pp. 200-201
Author(s):  
Phil Fischer ◽  
D.L. Welch ◽  
P. Cote ◽  
M. Mateo ◽  
Barry F. Madore

High-precision radial velocity measurements have been obtained for 62 stars in the young LMC cluster NGC 1866 using the Las Campanas 2.5m with échelle spectrograph. The mass-weighted mean-square velocity dispersion is σ2 = 6.5 ± 1.3 km2 s−2. The mass of the cluster M(r < 20) = 8.1 ± 1.6 × 104M⊙, implying a M/L of 0.20 ± 0.04 in solar units.


2020 ◽  
Vol 72 (6) ◽  
Author(s):  
Takuya Takarada ◽  
Bun’ei Sato ◽  
Masashi Omiya ◽  
Yasunori Hori ◽  
Michiko S Fujii

Abstract We report on a radial-velocity search for short-period planets in the Pleiades open cluster. We observed 30 Pleiades member stars at the Okayama Astrophysical Observatory with the High Dispersion Echelle Spectrograph. To evaluate and mitigate the effects of stellar activity on radial-velocity (RV) measurements, we computed four activity indicators (full width at half maximum, Vspan, Wspan, and SHα). Among our sample, no short-period planet candidates were detected. Stellar intrinsic RV jitter was estimated to be 52 m s−1, 128 m s−1, and 173 m s−1 for stars with $v$ sin i of 10 km s−1, 15 km s−1, and 20 km s−1, respectively. We determined the planet occurrence rate from our survey and set the upper limit to 11.4% for planets with masses 1–13 MJUP and period 1–10 d. To set a more stringent constraint on the planet occurrence rate, we combined the result of our survey with those of other surveys targeting open clusters with ages in the range 30–300 Myr. As a result, the planet occurrence rate in young open clusters was found to be less than 7.4%, 2.9%, and 1.9% for planets with an orbital period of 3 d and masses of 1–5, 5–13, and 13–80 MJUP, respectively.


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