IR spectroscopy

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IR spectroscopy

Post by Sirius_Alpha on 6th November 2008, 7:01 pm

I've been considering the idea of infrared Doppler spectroscopy for some time, and given a sufficiently bright source (or a sufficiently sensitive instrument), what are the odds of detecting exomoons around some of these IR-detected planets? (i.e. 2M1207 b, GQ Lupi b, 1RXS ... b, UScoCTIO 108 b, AB Pic b?)

I'm guessing RV signals would be extremely small, but what about jitter? I'm guessing a 5 M_j object probably doesn't have much jitter. Would the ability to detect exomoons be limited only to the sensitivity of the instrument?

Also, this paper,
Abstract wrote:We present a high-precision infrared (~2.3 Ám) radial velocity study of late-type stars using spectra obtained with NIRSPEC at the W. M. Keck Observatory. Precise radial velocities are determined by modeling optimally extracted spectra as a combination of synthetic stellar and telluric spectra. Success relies heavily on the use of proper extraction techniques, which offer many unexplored challenges at infrared wavelengths. Our prescription uses published, albeit heavily modified, reduction techniques in conjunction with an original software suite developed to coordinate analysis. We compare the impact of our modifications to various reduction techniques, as well as discuss the relative significance of issues thereby identified. Radial velocity precisions of ~65 m/s are currently achieved, based on observations of old late-type stars with no known planets; these observations span many observing runs and a temporal baseline of 2.4 years. Precisions continue to improve. As is, we apply this technique to a sample of late-type chromospherically active stars (e.g. EV Lac) to investigate the effects of star spot noise on radial velocities determined at infrared wavelengths. Based on comparisons with previous optical observations of these same stars, we can now show that infrared radial velocity measurements mitigate star spot noise significantly. We also apply our technique to late-type members of the Beta Pic Moving Group to search for young planets. For most stars, these observations exclude the presence of any short period (< 10 days) planets more massive than ~1 Jupiter, or 100 day period planets more massive than ~2 Jupiter. One clear exception shows relatively large radial velocity variations (~500 m/s), characteristic of a star orbited by a massive, small separation planet. Unfortunately the sampling pattern for this star is too sparse to estimate orbital properties. Follow-up observations are underway. The research was funded in part by NSF/ASG grant #0708944.

Emphases, mine.

So it seems IR spectroscopy might aid in the detection of planets around active stars?

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