Detecting Extra-Solar Planets: Crossing the Jupiter Threshold

小行星9520443 我们的太阳系仍然是已知的唯一围绕正常星星的行星系统。 目前的观测工作未能发现质量为木星三倍的太阳系外行星，它们绕着大约30颗太阳型恒星运行。 将通过观察由多普勒效应测量的hmst恒星的反射加速度来搜索太阳系外行星。 由于我们的太阳主要由于木星而执行13米/秒的速度幅度变化（从太阳系外观察），计划实现2米/秒的多普勒测量精度，以确保检测围绕其他恒星运行的巨行星。 这种前所未有的多普勒测量精度源于光谱仪设计和光谱分析的新发展。 此外，一个新的施密特相机已专门设计，以产生一个尖锐的，对称的点扩散函数（PSF）的全格式的快速中阶梯光栅光谱仪。 将使用一个2048 x2048 CCD探测器收集1000埃波长范围内的所有恒星多普勒信息，分布在30，000 CCD像素上。 光谱中的多普勒频移的分析将包括所有光谱仪参数（波长尺度和PSF）和多普勒频移的全新的同时解决方案。 多普勒测量的详细误差预算产生2米/秒的底线精度。 这种精确度使得在5 sigma水平上可以检测到类似木星的行星，而类似土星的行星将被边缘检测到。 对类太阳恒星光谱的实际测试观测使其精度达到3.5米/秒。 下一代多普勒分析技术将提高这一精度。 然而，通过对五组曝光进行平均，平均值的误差已经小于2米/秒。 计划监测15颗G型和K型星，并对多普勒波长偏移进行测量，精确度为2米/秒。 在测量多普勒波长偏移时，将以5米/秒的精度观测另外85颗恒星（取决于个别恒星的亮度）。 这些新技术将使人们有可能在3年内观测恒星和测量速度变化，这表明有巨行星存在。

9520443 Marcy Our Solar System remains the lone planetary system that is known to be around a normal star. Current observational efforts have failed to discover extrasolar planets at a threshold of the mass three times that of Jupiter orbiting approximately 30 solar-type stars. A search for extrasolar planets, by observing the reflex acceleration of the hmst stars, measured by the Doppler effect, will be carried out. As our Sun executes a velocity amplitude change of 13 m/sec (as observed from outside the solar system) due primarily to Jupiter, it is planned to achieve a Doppler measurement precision of 2 m/sec to ensure detection of giant planets orbiting around other stars. This unprecedented Doppler measurement precision stems from novel developments in spec- trometer design and spectral analysis. In addition, a new Schmidt camera has been specially engineered to produce a sharp, symmetric Point Spread Function (PSF) over the full format of a fast echelle spectrometer. A 2048x2048 CCD detector will be used to gather all stellar Doppler information, within 1000 Angstroms wavelength, spread over 30,000 CCD pixels. The analysis of the Doppler shifts in the spectra will consist of an entirely novel simultaneous solution of all spectrometer parameters (wavelength scale and PSF) and Doppler shift. A detailed error budget for the Doppler measurements yields a bottom line accuracy of 2 m/sec. This precision renders the detection of Jupiter-like planets detectable at the 5 sigma level, and Saturn-like planets will be marginally detectable. Actual test observations of the spectra of Solar-like stars enable one to achieve a precision of 3.5 m/sec. This accuracy will be improved with the next-generation Doppler analysis techniques. Already, however, by averaging sets of five exposures, the error in the mean is less than 2 m/sec. It is planned to monitor 15 G-type and K- type stars and make measurements of the Doppler wavelength shifts to a precision of 2 m/sec. Eighty five other stars will be observed with an accuracy of 5 m/sec in the measurement of the Doppler wavelength shifts (depending on the brightness of the individual stars). These new techniques will make it possible to observe stars and measure velocity changes, indicative of giant planets, within 3 years.