The Sangamo Frontier: History and Archaeology in the Shadow of Lincoln

Review of: "The Sangamo Frontier: History and Archaeology in the Shadow of Lincoln," by Robert Mazrim

Rural African Americans and Progressive Reform

Histories of African Americans in the postbellum rural South tend to depict sharecroppers and tenants as victims of the crop lien system, racism, and the capitalization of agriculture. This paper concentrates instead on rural re? formers who celebrated life in the country and believed that comfortable homes, better schools, and wholesome residents could free blacks from bondage. Their agrarian ideology reflected Euro-American influences; most believed in the Jeffersonian rhetoric that linked land ownership to virtue and independence. Because they realized that the crop lien system made prop? erty acquisition an impossible dream for most blacks, they advocated diversification and sustainable agriculture as a means to challenge the eco? nomic limitations of this system. They pursued reform from their office desks rather than from cotton fields. Some posed political challenges, but most African American agrarians, intent on creating an educated, moral, and thrifty rural population, found that cooperating with white authority furthered their goals. Rural African American landowners looked toward these new leaders for guidance during a period of intense change between the 1880s and World War I

Early-type Stars: Most Favorable Targets for Astrometrically Detectable Planets in the Habitable Zone

Early-type stars appear to be a difficult place to look for planets astrometrically. First, they are relatively heavy, and for fixed planetary mass the astrometric signal falls inversely as the stellar mass. Second, they are relatively rare (and so tend to be more distant), and for fixed orbital separation the astrometric signal falls inversely as the distance. Nevertheless, because early-type stars are relatively more luminous, their habitable zones are at larger semi-major axis. Since astrometric signal scales directly as orbital size, this gives early-type stars a strong advantage, which more than compensates for the other two factors. Using the Hipparcos catalog, we show that early-type stars constitute the majority of viable targets for astrometric searches for planets in the habitable zone. We contrast this characteristic to transit searches, which are primarily sensitive to habitable planets around late-type stars.Comment: Submitted to ApJ Letters, 8 pages including 2 figure

African Americans and Land Loss in Texas: Government Duplicity and Discrimination Based on Race and Class

African American Farmers and Land Loss in Texas, surveys the ways that discrimination at the local, state, and national levels constrained minority farmers during the twentieth century. It considers the characteristics of small-scale farming that created liabilities for landowners regardless of race, including state and federal programs that favored commercial and agribusiness interests. In addition to economic challenges African American farmers had to negotiate racism in the Jim Crow South. The Texas Agricultural Extension Service, the state branch of the USDA\u27s Extension Service, segregated in 1915. The Negro division gave black farmers access to information about USDA programs, but it emphasized their subordinate position relative to white farmers. The Civil Rights Act of 1964 did not reverse decades of racial discrimination. Instead, USDA officials relied on federalism, a theory as old as the Constitution, to justify their tolerance of civil rights violations in Texas and elsewhere. Then, special needs legislation passed during the 1970s and 1980s did not realize its potential to serve ethnically diverse and economically disadvantaged rural Texans. Discrimination based on race combined with a bias toward commercial production. This crippled most black farmers and led to their near extinction

Rotational velocities of low-mass stars in the Pleiades and Hyades

We have obtained high-resolution spectra of 89 M dwarf members of the Pleiades and Hyades and have derived radial velocities, H-alpha equivalent widths, and spectroscopic rotational velocities for these stars. Typical masses of the newly-observed Pleiades and Hyades stars are ~ 0.4 M_{\sun} and ~ 0.2 M_{\sun}, respectively. We combine our new observations with previously published data to explore the rotational evolution of young stars with M < 0.4 M_\sun. The average rotation rate in the Hyades (age 600 Myr) is about 0.4 that of the Pleiades (110 Myr), and the mean equivalent widths of H-alpha are also lower. As found in previous studies, the correlation between rotation and chromospheric activity is identical in both clusters, implying that the lower activity in the Hyades is a result of the lower rotation rates. We show that a simple scaling of the Pleiades rotational distribution for M \leq 0.4 M_{\sun}, corrected for the effects of structural evolution, matches that of the Hyades if the average angular momentum loss from the Pleiades to the Hyades age is factor of \approx 6. This suggests that the distribution of initial angular momenta and disk-locking lifetimes for the lowest mass stars was similar in both clusters. We argue that this result provides further evidence for a saturation of the angular momentum loss rate at high rotational velocities.Comment: 22 pages, 11 figures, accepted for publication in The Astronomical Journal, tentatively scheduled for March 200

The California Planet Survey. I. Four New Giant Exoplanets

We present precise Doppler measurements of four stars obtained during the past decade at Keck Observatory by the California Planet Survey (CPS). These stars, namely, HD 34445, HD 126614, HD 13931, and Gl 179, all show evidence for a single planet in Keplerian motion. We also present Doppler measurements from the Hobby-Eberly Telescope (HET) for two of the stars, HD 34445 and Gl 179, that confirm the Keck detections and significantly refine the orbital parameters. These planets add to the statistical properties of giant planets orbiting near or beyond the ice line, and merit follow-up by astrometry, imaging, and space-borne spectroscopy. Their orbital parameters span wide ranges of planetary minimum mass (M sin i = 0.38-1.9 M(Jup)), orbital period (P = 2.87-11.5 yr), semimajor axis (a = 2.1-5.2 AU), and eccentricity (e = 0.02-0.41). HD 34445 b (P = 2.87 yr, M sin i = 0.79 MJup, e = 0.27) is a massive planet orbiting an old, G-type star. We announce a planet, HD 126614 Ab, and an M dwarf, HD 126614 B, orbiting the metal-rich star HD 126614 (which we now refer to as HD 126614 A). The planet, HD 126614 Ab, has minimum mass M sin i = 0.38 MJup and orbits the stellar primary with period P = 3.41 yr and orbital separation a = 2.3 AU. The faint M dwarf companion, HD 126614 B, is separated from the stellar primary by 489 mas (33 AU) and was discovered with direct observations using adaptive optics and the PHARO camera at Palomar Observatory. The stellar primary in this new system, HD 126614 A, has the highest measured metallicity ([ Fe/ H] = + 0.56) of any known planet-bearing star. HD 13931 b (P = 11.5 yr, M sin i = 1.88 MJup, e = 0.02) is a Jupiter analog orbiting a near solar twin. Gl 179 b (P = 6.3 yr, M sin i = 0.82 M(Jup), e = 0.21) is a massive planet orbiting a faint M dwarf. The high metallicity of Gl 179 is consistent with the planet-metallicity correlation among M dwarfs, as documented recently by Johnson & Apps.NSF AST-0702821NASA NNX06AH52GMcDonald Observator