Notes on Ohioan Mammals

Author Institution: 6559 Salem Pike, Cincinnati, Ohio ; Museum of Natural History, University of Illinois, Urban

Radial Velocity Studies of Close Binary Stars.III

Radial velocity measurements and simple sine-curve fits to the orbital velocity variations are presented for the third set of ten contact binary systems: CN And, HV Aqr, AO Cam, YY CrB, FU Dra, RZ Dra, UX Eri, RT LMi, V753 Mon, OU Ser. All systems but two are contact, double-line spectroscopic binaries with four of them (YY CrB, FU Dra, V753 Mon, OU Ser) being the recent discoveries of the Hipparcos satellite project. The most interesting object is V753 Mon with the mass-ratio closest to unity among all contact systems (q = 0.970 pm 0.003) and large total mass ((M1+M2)sin^3i = 2.93 pm 0.06). Several of the studied systems are prime candidates for combined light and radial-velocity synthesis solutions.Comment: submitted for publication in Astronomical Journal; 3 figures, 2 table

Radial Velocity Studies of Close Binary Stars. XI

Radial-velocity measurements and sine-curve fits to the orbital radial velocity variations are presented for ten close binary systems: DU Boo, ET Boo, TX Cnc, V1073 Cyg, HL Dra, AK Her, VW LMi, V566 Oph, TV UMi and AG Vir. By this contribution, the DDO program has reached the point of 100 published radial velocity orbits. The radial velocities have been determined using an improved fitting technique which uses rotational profiles to approximate individual peaks in broadening functions. Three systems, ET Boo, VW LMi and TV UMi, were found to be quadruple while AG Vir appears to be a spectroscopic triple. ET Boo, a member of a close visual binary with $P_{vis} = 113$ years, was previously known to be a multiple system, but we show that the second component is actually a close, non-eclipsing binary. The new observations enabled us to determine the spectroscopic orbits of the companion, non-eclipsing pairs in ET Boo and VW LMi. The particularly interesting case is VW LMi, where the period of the mutual revolution of the two spectroscopic binaries is only 355 days. While most of the studied eclipsing pairs are contact binaries, ET Boo is composed of two double-lined detached binaries and HL Dra is single-lined detached or semi-detached system. Five systems of this group were observed spectroscopically before: TX Cnc, V1073 Cyg, AK Her (as a single-lined binary), V566 Oph, AG Vir, but our new data are of much higher quality than the previous studies.Comment: Accepted by AJ, August 2006, 10 figures, 3 table

Absolute dimensions of the unevolved B-type eclipsing binary GG Orionis

We present photometric observations in B and V as well as spectroscopic observations of the detached, eccentric 6.6-day double-lined eclipsing binary GG Ori, a member of the Orion OB1 association. Absolute dimensions of the components, which are virtually identical, are determined to high accuracy (better than 1% in the masses and better than 2% in the radii) for the purpose of testing various aspects of theoretical modeling. We obtain M(A) = 2.342 +/- 0.016 solar masses and R(A) = 1.852 +/- 0.025 solar radii for the primary, and M(B) = 2.338 +/- 0.017 solar masses and R(B) = 1.830 +/- 0.025 solar radii for the secondary. The effective temperature of both stars is 9950 +/- 200 K, corresponding to a spectral type of B9.5. GG Ori is very close to the ZAMS, and comparison with current stellar evolution models gives ages of 65-82 Myr or 7.7 Myr depending on whether the system is considered to be burning hydrogen on the main sequence or still in the final stages of pre-main sequence contraction. We have detected apsidal motion in the binary at a rate of dw/dt = 0.00061 +/- 0.00025 degrees per cycle, corresponding to an apsidal period of U = 10700 +/- 4500 yr. A substantial fraction of this (approximately 70%) is due to the contribution from General Relativity.Comment: To appear in The Astronomical Journal, December 200

Radial Velocity Studies of Southern Close Binary Stars.I

Radial-velocity measurements and sine-curve fits to the orbital velocity variations are presented for nine contact binaries, V1464 Aql, V759 Cen, DE Oct, MW Pav, BQ Phe, EL Aqr, SX Crv, VZ Lib, GR Vir; for the first five among these, our observations are the first available radial velocity data. Among three remaining radial velocity variables, CE Hyi is a known visual binary, while CL Cet and V1084 Sco are suspected to be multiple systems where the contact binary is spectrally dominated by its companion (which itself is a binary in V1084 Sco). Five additional variables, V872 Ara, BD Cap, HIP 69300, BX Ind, V388 Pav, are of unknown type, but most are pulsating stars; we give their mean radial velocities and Vsini.Comment: to appear in AJ October 2006; 3 figure

SS Ari: a shallow-contact close binary system

Two CCD epochs of light minimum and a complete R light curve of SS Ari are presented. The light curve obtained in 2007 was analyzed with the 2003 version of the W-D code. It is shown that SS Ari is a shallow contact binary system with a mass ratio $q=3.25$ and a degree of contact factor f=9.4(\pm0.8%). A period investigation based on all available data shows that there may exist two distinct solutions about the assumed third body. One, assuming eccentric orbit of the third body and constant orbital period of the eclipsing pair results in a massive third body with $M_3=1.73M_{\odot}$ and P_3=87.0$yr. On the contrary, assuming continuous period changes of the eclipsing pair the orbital period of tertiary is 37.75yr and its mass is about$0.278M_{\odot}$. Both of the cases suggest the presence of an unseen third component in the system.Comment: 28 pages, 9 figures and 5 table

A Census of the Chamaeleon I Star-Forming Region

Optical spectroscopy has been obtained for 179 objects that have been previously identified as possible members of the cluster, that lack either accurate spectral types or clear evidence of membership, and that are optically visible (I<18). I have used these spectroscopic data and all other available constraints to evaluate the spectral classifications and membership status of a total sample of 288 candidate members of Chamaeleon I that have appeared in published studies of the cluster. The latest census of Chamaeleon I now contains 158 members, 8 of which are later than M6 and thus are likely to be brown dwarfs. I find that many of the objects identified as members of Chamaeleon I in recent surveys are actually field stars. Meanwhile, 7 of 9 candidates discovered by Carpenter and coworkers are confirmed as members, one of which is the coolest known member of Chamaeleon I at a spectral type of M8 (~0.03 M_sun). I have estimated extinctions, luminosities, and effective temperatures for the members and used these data to construct an H-R diagram for the cluster. Chamaeleon I has a median age of ~2 Myr according to evolutionary models, and hence is similar in age to IC 348 and is slightly older than Taurus (~1 Myr). The measurement of an IMF for Chamaeleon I from this census is not possible because of the disparate methods with which the known members were originally selected, and must await an unbiased, magnitude-limited survey of the cluster.Comment: 59 pages, 22 figure

The {\eta}'-carbon potential at low meson momenta

The production of $\eta^\prime$ mesons in coincidence with forward-going protons has been studied in photon-induced reactions on $^{12}$C and on a liquid hydrogen (LH$_2$) target for incoming photon energies of 1.3-2.6 GeV at the electron accelerator ELSA. The $\eta^\prime$ mesons have been identified via the $\eta^\prime\rightarrow \pi^0 \pi^0\eta \rightarrow 6 \gamma$ decay registered with the CBELSA/TAPS detector system. Coincident protons have been identified in the MiniTAPS BaF$_2$ array at polar angles of $2^{\circ} \le \theta _{p} \le 11^{\circ}$. Under these kinematic constraints the $\eta^\prime$ mesons are produced with relatively low kinetic energy ($\approx$ 150 MeV) since the coincident protons take over most of the momentum of the incident-photon beam. For the C-target this allows the determination of the real part of the $\eta^\prime$-carbon potential at low meson momenta by comparing with collision model calculations of the $\eta^\prime$ kinetic energy distribution and excitation function. Fitting the latter data for $\eta^\prime$ mesons going backwards in the center-of-mass system yields a potential depth of V = $-$(44 $\pm$ 16(stat)$\pm$15(syst)) MeV, consistent with earlier determinations of the potential depth in inclusive measurements for average $\eta^\prime$ momenta of $\approx$ 1.1 GeV/$c$. Within the experimental uncertainties, there is no indication of a momentum dependence of the $\eta^\prime$-carbon potential. The LH$_2$ data, taken as a reference to check the data analysis and the model calculations, provide differential and integral cross sections in good agreement with previous results for $\eta^\prime$ photoproduction off the free proton.Comment: 9 pages, 13 figures. arXiv admin note: text overlap with arXiv:1608.0607

Clonal karyotype evolution involving ring chromosome 1 with myelodysplastic syndrome subtype RAEB-t progressing into acute leukemia

s Karyotypic evolution is a well-known phenomenon in patients with malignant hernatological disorders during disease progression. We describe a 50-year-old male patient who had originally presented with pancytopenia in October 1992. The diagnosis of a myelodysplastic syndrome (MDS) FAB subtype RAEB-t was established in April 1993 by histological bone marrow (BM) examination, and therapy with low-dose cytosine arabinoside was initiated. In a phase of partial hernatological remission, cytogenetic assessment in August 1993 revealed a ring chromosome 1 in 13 of 21 metaphases beside BM cells with normal karyotypes {[}46,XY,r(1)(p35q31)/46,XY]. One month later, the patient progressed to an acute myeloid leukemia (AML), subtype M4 with 40% BM blasts and cytogenetic examination showed clonal evolution by the appearance of additional numerical aberrations in addition to the ring chromosome{[}46,XY,r(1),+8,-21/45,XY,r(1),+8,-21,-22/46, XY]. Intensive chemotherapy and radiotherapy was applied to induce remission in preparation for allogeneic bone marrow transplantation (BMT) from the patient's HLA-compatible son. After BMT, complete remission was clinically, hematologically and cytogenetically (normal male karyotype) confirmed. A complete hematopoietic chimerism was demonstrated. A relapse in January 1997 was successfully treated using donor lymphocyte infusion and donor peripheral blood stem cells (PB-SC) in combination with GM-CSF as immunostimulating agent in April 1997, and the patient's clinical condition remained stable as of January 2005. This is an interesting case of a patient with AML secondary to MDS. With the ring chromosome 1 we also describe a rare cytogenetic abnormality that predicted the poor prognosis of the patient, but the patient could be cured by adoptive immunotherapy and the application of donor's PB-SC. This case confirms the value of cytogenetic analysis in characterizing the malignant clone in hernatological neoplasias, the importance of controlling the quality of an induced remission and of the detection of a progress of the disease. Copyright (c) 2006 S. Karger AG, Basel