Integral spectroscopy of the nebula GM 1-29 and the star PV Cep

Integral spectroscopy data for the nebula GM 1-29 and the source star PV Cep obtained on the 2.6-m telescope at the Byurakan Observatory are presented. The structure and kinematics of a collimated emission outflow directed along the axis of the nebula are studied. Changes in the radial velocity and intensity of the absorption component of the nebular Hα line are observed and studied; these are interpreted as a result of an anisotropy in the stellar wind at distances on the order of several stellar radii, where this absorption is formed. __________ Translated from Astrofizika, Vol. 51, No. 3, pp. 461–468 (August 2008).     

Mid- and far-infrared variability of PV Cep

We present the collection of all the mid- and far-IR observations (λ=3–170 μm) of the young eruptive variable PV Cep available so far in the literature. These data allow us to confirm that flux variability is a prominent feature at mid-IR wavelength (λ=3–25 μm). Color-magnitude plots clearly indicate that the observed variability is not extinction-driven, but mainly influenced by fluctuations of the mass accretion rate. We interpret such variability as due to a hot spot created onto the stellar surface by the column of accreting matter, which heats the inner parts of the disk and determines the observed increase of the near- mid-IR luminosity. A quantitative characterization is given for both the spot itself and the additional thermal component created by it. Far-IR data (λ=60–170 μm) are consistent with the presence of a temperature stratification in a massive and quite un-evolved circumstellar disk.     

Search for HH-objects and emission stars in star formation regions. VI. Herbig-Haro objects and emission stars in the region of the GM 1-64 and GM 2-4 nebulae

Three new Herbig-Haro and 12 emission stars, mainly belonging to the T Tau class, have been discovered in a study of the region of the GM 1-64 and GM 2-4 nebulae in the direction of the galactic anticenter. GM 1-64 and GM 2-4 are typical cometary nebulae illuminated by emission stars. In GM 2-4 the central star is surrounded by a dense dust envelope and is observed only in the IR. Two stellar-like sources which are bright in the IR are found in this same region and can be regarded as young, Class 1 stars. One of them (CPM 19) is surrounded by a compact group of fainter PMS objects. It is found that CPM 19 shows up clearly in the optical range and undergoes large amplitude brightness variations.     

Variations in the brightness and polarization of W Cep

The hypothesis that W Cep has an eclipsing variability is discussed on the basis of our photometric and polarimetric observations of it from 1983–2003. Here we attempt to use our observations of W Cep to construct an average light curve, after separating out the slow variation, with the elements JD_min=2448105^d+2090^d. A strong variability is found from period to period at phases of 0.1–0.3 that may be caused by a variable flow of matter between the components. __________ Translated from Astrofizika, Vol. 49, No. 2, pp. 187–196 (May 2006).     

Long-term photometric behavior of the PMS stars V977 Cep and V982 Cep in the vicinity of NGC 7129

Long-term BV RI photometric light curves of the pre-main sequence stars V977 Cep and V982 Cep during the period from 2000 October to 2016 August are presented. The stars are located in the vicinity of the reflection nebula NGC 7129. Our photometric data show that both stars exhibit strong photometric variability in all optical passbands, which is typical for Classical T Tauri stars. Using our observational data we analyze the reasons for the observed brightness variations. In the case of V977 Cep we identify previously unknown periodicity in its light curve.     

若干恒星形成区的^12CO（J=1—0）与^13CO（J=1—0）观测

首次利用紫金山天文台青海观测站13.7m毫米波射电望远镜对若干分子云与恒星形成区的~(12)CO(J=1—0)和~(13)CO(J=1—0)分子辐射进行了观测,得到了各自中心位置的谱线轮廓。作为一个实例本文将介绍如何通过对分子云~(12)CO(J=1—0)和~(13)CO(J=1—0)谱线的综合分析与计算得到云中的物理参数。     

Spectrographic study of Nova Vulpeculae 1976 (NQ VUL)

Nova Vulpeculae was observed from November 11 to December 16, 1976, at the Beijing Observatory with the grating spectrograph attached to the Cassegrain focus of the 60/90 Schmidt telescope.This paper gives the idectification of the spectral features, the expansion velocities, the photoionization temperatures, the colour temperatures and the Balmer decrement. In wavelength range λλ 3400 – 6700 the principal lines are of HI, FeII, NaI, NII, CaII, TiII, [OI], [NII] atoms or ions. The majority of lines are of P Cyg type. The expansion velocities as derived from measurements of the absorption spectra amount to about 500 – 2200 km/s. Photoionisation temperatures are higher than the corresponding colour temperatures. They increased as the nova became fainter.     

Thermal infrared (8-13 μm) spectra of 29 asteroids: the Cornell Mid-Infrared Asteroid Spectroscopy (MIDAS) Survey

We report the results of the Cornell Mid-IR Asteroid Spectroscopy (MIDAS) survey, a program of ground-based observations designed to characterize the 8-13 μm spectral properties of a statistically significant sample of asteroids from a wide variety of visible to near-IR spectral classes. MIDAS is conducted at Palomar Observatory using the Spectrocam-10 (SC-10) spectrograph on the 200-in Hale telescope. We have measured the mid-infrared spectra of twenty-nine asteroids and have derived temperature estimates from our data that are largely consistent with the predictions of the standard thermal model. We have also generated relative emissivity spectra for the target asteroids. On only one asteroid, 1 Ceres, have we found emissivity features with spectral contrast greater than 5%. Our spectrum of 4 Vesta suggests emissivity variation at the 2-3% level. Published spectra of several of the small number of asteroids observed with ISO (six of which are also included in our survey), which appeared to exhibit much stronger emissivity features, are difficult to reconcile with our measurements. Laboratory work on mineral and meteorite samples has shown that the contrast of mid-IR spectral features is greatly reduced at fine grain sizes. Moreover, the NEAR mission found that 433 Eros is covered by a relatively thick fine-grained regolith. If small bodies in general possess such regoliths, their mid-IR spectral features may be quite subtle. This may explain the evident absence of strong emissivity variation in the majority of the MIDAS spectra.     

Comparative Study of the Optical Spectra of Comets C/1996 B2 (Hyakutake) and C/1995 O1 (Hale-Bopp)

Earth, Moon, and Planets -     

Investigation of light curves of young irregular variables. 1. SV Cep and CQ Tau

Institute of Astrophysics, Academy of Sciences of Tadzhikistan. Shternberg State Astronomical Institute. Odessa Observatory. Translated from Astrofizika, Vol. 36, No. 1, pp. 55–60, January–February, 1993.     

OMC--3的13CO(1--0)和C18O(1--0)分子辐射

利用紫金山天文台青海站的 １３．７ ｍ毫米波望远镜,对 Ｏｒｉｏｎ Ａ分子云中的 ＯＭＣ－３区域,进行了较高分辨率的１３ＣＯ（Ｊ＝１－０）和Ｃ１８Ｏ（Ｊ＝１－０）分子辐射的成图观测．给出了该分子云中１３ＣＯ和 Ｃ１８Ｏ云核分布的整体结构和平均物理参数．观测发现,该分子云的１３ＣＯ和 Ｃ１８Ｏ的云核中心分别与最年轻的天体－Ｃｌａｓｓ ０类源 ＭＭＳＩ, ＭＭＳ４,ＭＭＳ６和ＭＭＳ７,ＭＭＳ８;ＭＭＳ９成协．此外,通过分析ＯＭＣ－３整个区域的速度场结构,发现沿 Ｃ１８Ｏ和１３ＣＯ云核方向从南到北有一个～ １．７ｋｍ／ｓ的速度场梯度,而分子云的红、蓝移团块则分别趋于云的北部和南部．并对ＯＭＣ－３区的恒星形成特征进行了讨论．     

Photometric investigations of distant comets C/2002 VQ94 (LINEAR) and 29P/Schwassmann-Wachmann-1

We present an analysis of the results of photometric investigations of two distant comets, C/2002 VQ94 (LINEAR) and 29P/Schwassmann-Wachmann-1, obtained with the 6-m telescope of the Special Astrophysical Observatory of the Russian Academy of Sciences. The comets under study demonstrate sufficient activity out of the zone of water ice sublimation (at heliocentric distances longer than 5 AU). In the spectra of the investigated comets, we found the CO⁺ and N₂⁺ emission. The presence of this emission may say that the comets were formed in the outer parts of the Solar System, in a protoplanetary cloud at a temperature ≤25 K. We found that the photometric maximum of the ionosphere (in the CO⁺ filter) of the comet C/2002 VQ94 (LINEAR) is shifted relative to the photometric center of the dust coma by 1.4″ (7.44 × 10³ km) in the direction deflected by 63° from the direction to the Sun. Using special filters to process the images, we picked out active structures (jets) in the dust coma of the 29P/Schwassmann-Wachmann-1 comet.     

Search for Cometary Activity in KBO (24952) 1997 QJ4

Deep imaging was performed with the Subaru Telescope on Mauna Keacentered on the position of the KBO (24952) 1997 QJ₄ on 2half-nights during October 2002. A deep search for evidence of a dustcoma was conducted which could be indicative of cometary activity downto a limit of m_V = 31 mag arcsec^-2. No coma was detected, and from this sensitive upper limits on dust production can be set at Q <0.01 kg s^-1. Brightness variations consistent with rotationalmodulation were seen, implying a period of rotation longer than 4 hrs,with a range > 0.3 mag corresponding to a minimum projected axis ratioof 1:1.3.     

Gas and dust release from comet West (1976VI) nuclear fragments

Emission fluxes of CN, G₂ and C₃ carbon-bearing molecular species observed in the spectra of the nuclear fragment A and D of comet West (1976VI) are analysed in the framework of Haser's two-component model with radial outflow symmetry. Gas production rates have been derived and their ratios obtained. We find these vary as Q r ⁿ (where 1.0r2.6 is the heliocentric distance in AU) with photometric parametern = -4.11 (CN), -2.68 (C₂), -1.89 (C₃) andQ _x /Q _y r ⁿ withn = 2.22 (C₃/CN), 1.42 (C₂/CN), -0.79 (C₂/C₃). The gas-to-dust ratio, dust production rates in arbitrary units, total number of dust particles in the field of view and an effective radius R_eff 2.0 km for the principal nuclear fragmentA is also estimated.     

Aperture Synthesis C~(18)O(1-0) Observations of L1 5 51 IRS5

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