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91.
92.
93.
R. F. Griffin 《Journal of Astrophysics and Astronomy》1988,9(3):127-136
Photoelectric radial-velocity measurements show that HD 106947 is a double-lined spectroscopic binary. The components have
spectral types of about F6 V and G5 V and are in a 59-day orbit of moderate eccentricity. The system is a member of the Coma
Cluster. 相似文献
94.
Vanessa Doublier 《Astrophysics and Space Science》2002,281(1-2):211-212
Planetary Nebulae have proven to be an essential key to understand the long term chemical enrichment of the interstellar medium
due to low mass stars. They allow to study the original abundances of the star, and the effect of the star on the interstellar
medium. Blue compact dwarf galaxies are known to host violent star formation in very heavy element depleted environments.
They also show traces of past star formation (Doublier et al., 1999; 2001), including AGB starsand red giants which are responsible
for long term enrichment. However, models fails to reproduce the low metallicities observed if those stars are taken into
account. We observed PNe in BCDGs, and made a comparative study of the abundances in the HII regions and of the PNe.
This revised version was published online in September 2006 with corrections to the Cover Date. 相似文献
95.
96.
Summary The unprecedented quality of the IRAS data prompted a series of papers reinvestigating the origin of the galactic infrared/submillimeter radiation and the nature of the heating sources of the interstellar dust. The scope of this paper is to review the main results of these new studies. Sect. 1 contains a general introduction to the subject and an overview of the earlier work. In Sect. 2 and 3, we summarize our current knowledge on dust properties and on the interstellar radiation field. Then, we present the recent interpretations of the infrared emission of our Galaxy, which are based on the IRAS data: in Sect. 4 we present the results from the galactic disk; Sect. 5 covers the question of the contribution from small dust particles, and in Sect. 6 we describe the infrared radiation from the galactic center. The nature of the heating sources and the origin of the galactic infrared radiation is then discussed in Sect. 7. Finally, Sect. 8 presents a comparison of our Galaxy with external galaxies 相似文献
97.
98.
G. S. D. Babu 《Journal of Astrophysics and Astronomy》1987,8(3):219-226
Photoelectric and photographic photometry of twenty-nine stars was done in the field of the open cluster Collinder 97 ≡ OC1
506. Of these stars, a total of twenty-four have been found to be possible members. There is apparently no interstellar extinction
in the direction of this cluster which is in the constellation of Monoceros: itsE(B-V) = 0.0 mag. This cluster is situated at a distance of 0.63 ± 0.01 kpc, which is well within the local arm of our Galaxy. The
age of this cluster is in the range of 1 × 108 to 5.9 × l08 yr, which puts it in an older age group. Thus, it cannot be specifically considered as a spiral-arm tracer in the study of
our Galaxy. 相似文献
99.
We use data on open star clusters (OSCs) from the Homogeneous Catalog of OSC Parameters to determine some of the parameters of the spiral structure of our Galaxy: the pitch angle of the spiral arms \(i = 21\mathop .\limits^ \circ 5\), the pattern speed Ωp = 20.4 ± 2.5 km s?1 kpc?1, and the initial phase of the spiral θ0 = 206°. The spiral pattern of the Galaxy proves to have been virtually unchanged over the last billion years, and signatures of the concentration of objects toward the spiral arms can be traced back to this age. However, the number of spiral arms in the structure cannot be determined from OSCs. 相似文献
100.
XPer的新发射相:光谱与红外观测 总被引:1,自引:0,他引:1
XPer的新发射相:光谱与红外观测杭恒荣,夏剑萍中国科学院紫金山天文台,南京210008中国科学院光学天文联合实验室关键词Be星/X射线双星,发射线,JHK测光1引言XPer是一颗Be/X射线双星(4U0352+30)的光学对应体[1-3],中子星的... 相似文献