+ Resolve Article
+ Follow Us
Follow on FacebookFollow on Facebook
Follow on TwitterFollow on Twitter

+ Translate
+ Subscribe to Site Feed
GeoScience Most Shared ContentMost Shared Content

Symbiotic stars and other Halpha emission line stars towards the Galactic Bulge

, : Symbiotic stars and other Halpha emission line stars towards the Galactic Bulge.

Symbiotic stars are interacting binaries with the longest orbital periods andtheir multi-component structure makes them rich astrophysical laboratories. Theaccretion of a high mass loss rate red giant wind on to a white dwarf (WD)makes them promising Type Ia supernovae (SNe Ia) progenitors. Systematicsurveys for new Galactic symbiotic stars are critical to identify new promisingSNe Ia progenitors (e.g. RS Oph) and to better estimate the total populationsize to compare against SNe Ia rates. Central to the latter objective isbuilding a complete census of symbiotic stars towards the Galactic Bulge. Herewe report on the results of a systematic survey of Halpha emission line starscovering 35 deg^2. It is distinguished by the combination of deep opticalspectroscopy and long-term lightcurves that improve the certainty of ourclassifications. A total of 20 bona-fide symbiotic stars are found (13 S-types,6 D-types and 1 D'-type), 35% of which show the symbiotic specificRaman-scattered OVI emission bands, as well as 15 possible symbiotic stars thatrequire further study (6 S-types and 9 D-types). Lightcurves show a diverserange of variability including stellar pulsations (semi-regular and Mira),orbital variations and slow changes due to dust. Orbital periods are determinedfor 5 S-types and pulsation periods for 3 D-types. The most significant D-typefound is H1-45 and its carbon Mira with a pulsation period of 408.6 days,corresponding to a distance of ~6.2+-1.4 kpc and M_K=-8.06+-0.12 mag. If H1-45belongs to the Galactic Bulge, then it would be the first bona-fide luminousGalactic Bulge carbon star. The lack of luminous carbon stars in the Bulge is alongstanding unsolved problem. A possible explanation for H1-45 may be that thecarbon enhancement was accreted from the progenitor of the WD companion. A widevariety of unusual emission line stars were also identified. (abridged).


Other references

Scalise, G.; Cirioni, O.; Balducci, M.; Lamura, L.; Giacometti, A.; Prete, M.S. del; Fiorentini, A.; Veccia, S., 1994: Pneumocystis carinii: in vitro culture from bronchoalveolar lavage fluid. Three media were tested for the in vitro culture of P. carinii from bronchoalveolar lavage (BAL) fluid. BAL samples from 5 AIDS patients with microscopically proven P. carinii pneumonia were used. Neither of the 2 acellular media tested supported...

Mertz, O.; Murtedza Mohamad; Magid, J.; Birch Thomsen, T.; Oksen, P., 2000: Collaboration on environmental research and education between universities in Denmark, Malaysia, Thailand and Southern Africa. This paper provides a brief introduction to an educational and research collaboration between a consortium of 3 Danish universities and universities in Malaysia, Thailand, and southern Africa, which focuses on sustainable land use and natural reso...

Moore, John William, 1934: Taxonomic studies of Raiatean plants. 1. An historical and nomenclatorial discussion supporting Piper methysticum G. Forster as the valid botanical name of the Polynesian ava, awa, kava, or kawa plant.[long dash]2. Bonnierella reflexa (Polyscias r. J. W. Moore) (p.6); Inga ynga (Mimos...

Shamsuddin A.H.M., 1989: Organic geochemistry of Oligocene-Miocene deposits of the Bengal Foredeep, Bangladesh. Journal of the Geological Society of India 33(4): 332-352

Tsuang, W.; Ahmed, K.; Eckert, D.; Helmy, T.; Grunenwald, P., 2008: Case report: CHD as a potential cause of chest pain in adult patients. American Family Physician 78(8): 911, 914-911, 914

Padmavathi, V.; Venugopal Reddy, K.; Padmaja, A.; Venugopalan, P., 2003: Unusual reaction of chloramine-T with araldoximes. Reaction of araldoximes with 4 equiv of chloramine-T in refluxing methanol produces N-(p-tolyl)-N-(p-tosyl)benzamides via addition of 2 equiv of chloramine-T to the intermediate nitrile oxide followed by extrusion of sulfur dioxide.

Kamenchik, M.G., 1952: Unusual variation of closed hepatic wound. Vestnik Khirurgii Imeni I. I. Grekova 72(4): 59-60

Vasil'ev B.D.; Smirnov S.V., 1981: Auditory acuity of turtles. Evoked potentials registered from the medullar acoustic nuclei of 4 spp. of turtles [Emys orbicularis, Clemmys caspica, Testudo horsfieldi, and T. graeca] show that sound perception in these animals is limited and lay in the narrow band of low fre...

Houman, H.; Ben Dahmen, F.; Ben Ghorbel, I.; Chouaib, S.; Lamloum, M.; Kchir, N.; Ben Ammar, A.; Miled, M., 2002: Behçet's disease associated with Crohn's disease. The association of Behçet's disease and of Crohn's disease is exceptional, and raises a nosological problem. A 24 year-old female developed since 1996 chronic diarrhea, abdominal pain, recurrent oral and genital ulcer and polyarthralgia...

Mateo P.L.; Privalov P.L., 1981: Pepsinogen denaturation is not a 2 state transition. Febs Letters 123(2): 189-192