在NGC 205中发现的一颗新星

１９９７年１１月２１日在作超新星巡天时,在仙女座星系ＮＧＣ２０５中发现了一颗新星．它的光谱中有强的巴尔末线,ＦｅＩＩ,ＨｅＩ和ＯＩ等发射线．谱线的蓝移与ＮＧＣ２０５的近似;根据ＮＧＣ２０５的距离模数得到的其极大附近时的绝对星等为－６３,是典型的新星在极大附近的光度值．可以肯定它发生在ＮＧＣ２０５中．光谱显示它是铁属新星．     

Nova Oph1994光谱观测研究

用２。１６ｍ望远镜及其卡焦光谱仪对Ｎｏｖａ Ｏｐｈ １９９４进行了一系列的光谱观测，其早期光谱中出现的大量Ｆｅｌｌ线表明它是一颗Ｆｅｌｌ型新星，而它的发射线的多峰结构在其它Ｆｅｌｌ型新星中是不多见的，它们根据得到的光谱和从国际互联网络得的测光资料，讨论了它的光谱特征和演化。     

在NGC205中发现的一颗新星

１９９７年１１月２１日在作超新星巡天时,在仙女座星系ＮＧＣ２５０中发现了一颗新星。它的光谱中有强的巴尔末线,Ｆｅｉｉ,ＨｅＩ和ＯＩ等发现线。谱线的蓝移与ＮＧＣ２５０的近似;根据ＮＧＣ２０５的距离模数得到的其极大附近时的绝对星等为－６．３,是典型的新星在极大附近的光度值,可以肯定发生在ＮＧＣ２０５中。光谱显示它是铁属新星。     

仙后座1995新星的光谱

在１９９５ 年至１９９７ 年,用２ ．１６ 米望远镜,５０?／ｍ ｍ 色散观测了仙后座１９９５ 新星的光谱．１９９５ 年的光谱以Ｆｅ Ⅱ及Ｈ Ⅰ的发射线为主要特征,所有发射线呈ＰＣｙｇ 轮廓,１９９６ 年光谱主要是Ｈ Ⅰ及Ｈｅ Ⅰ的发射,１９９７ 年光谱呈现很强的［Ｆｅ Ｘ］ 、［Ｆｅ ＶⅡ］ 、［Ｏ Ⅲ］ 发射,表明新星已进入星云阶段．以观测谱的连续谱估算了抛射物质的有效温度,算得１９９５ 年１０ 月１４ 日温度为２１３００Ｋ、１９９６ 年１０ 月２６ 日为９７００Ｋ、１９９７ 年１２ 月１６ 日为１０２００Ｋ．以测量谱线的流量估算抛射物质总质量约４ ．７ ×１０ － ５ Ｍ⊙,氦的丰度为ＮＨｅ／ＮＨ＝ ０ ．０４７ ．     

仙后座1995新星的光谱研究

１９９５ 至１９９８ 四年内用２ ．１６ 米望远镜、５０Ａ／ｍ ｍ 色散进行了仙后座１９９５ 新星的光谱观测。对取得的资料作了谱线证认、连续谱和谱线的流量、气壳膨胀速度、温度等测定,确定了新星气壳的电子密度和温度、估算了新星的抛射质量。指出该新星的若干特点并作了简要讨论。     

仙后座1995新星的光谱天空

１９９５至１９９８四川内用２．１６米望远镜、５０Ａ／ｍｍ色散进行了仙后座１９９５新星的光谱观测。对取得的资料作了谱线证认、连续谱和谱线的流量、气壳膨胀速度、温度等测定,确定了新星气壳的电子密度和温度、估算了新星的抛射质量。指出该新星的若干特点并作了简要讨论。     

恒星自转的引力昏暗效应对谱线的影响

对于快速自转的恒星,谱线的等值宽度（ＥＷ）受引力昏暗效应的影响,即使自转速度达到临界也是很小的;而谱线半宽（ＦＷＨＭ）受引力昏暗效应影响相对较大,在（ω≈０．９９）时,相对变化达到８％．对于光谱型在Ｂ０～Ｂ９范围内的主序星,谱线半宽的相对变化在自转速度较小时（ω＜０．８）与光谱型无关;在自转速度较大时（ω≈０．９９）,谱线半宽的相对变化随光谱次型的增加而下降．     

狐狸座PU(PU Vul)的光谱观测及其双星性质的初步讨论

我们从1981年9月至1983年12月对PU Vul进行了光谱观测,本文描述了其主要光谱特征及其变化。1981年9月PU Vul的光谱上只有吸收线,1982年10月出现很强的H_α发射线,1983年9月1日又出现H_β发射线,1983年10月H_α和H_β变得更强,11月发射线开始变弱,12月H_β发射线似已消失,但H-α发射线还是很强。整个观测期间该星光谱型基本与F型巨星相近。 这颗星很可能是一颗变化特别慢的慢新星,而且可能是由一颗M型巨星和一颗低光度的热子星组成的双星。     

1976年狐狸座新星(NQ Vul)的光谱研究

1976年11月11日-12月16日我们用60/90-厘米施密特卡氏反射光栅摄谱仪对狐狸座新星(NQ Vul)进行了照相光谱观测。在3400—6700A的波长范围内新星主要光谱成份为HI,Fell,NaI,Call,NII,Till,[OI],[NII]等,大多数谱线呈现PCyg型轮廓,根据吸收分量测得的膨胀速度是500—2200km/s。光致电离温度比色温度高,它们都随新星亮度的下降而升高。     

恒星自转的引力昏暗效应对谱线的影响

对于快速自转的恒星,谱线的等值宽度（ＥＷ）受引力昏暗效应的影响,即使自转速度达到临界也是很小的,而谱线半宽（ＦＷＨＭ）受引力昏暗效应影响相对较大,在（ｗ＝０．９９）时,相对变化达到８％。对于光谱型在Ｂ０￣Ｂ９范围内的主序星,谱线半宽的相对变化在自转速度较小时（ｗ〈０．８）与光谱型无关,在自转速度较大时（ｗ＝０．９９）,谱线半宽的相对变化随光谱次型的增加而下降。     

Circumstellar material around the proto-pne IRAS 10178-5958 and IRAS 11065-6026

Spectroscopy of Hen 401 (IRAS 10178-5958) and WRA 751 (IRAS 11065-6026) reveal strong HI, HeI, FeII and forbidden emission lines. Images of Hen 401 reveal the bipolar morphology of the nebula.     

HST/NICMOS Observations of M82

The irregular galaxy M82 is known as the archetypal starburst galaxy. Its proximity (3.5 Mpc) makes this galaxy an ideal laboratory for studying the properties of its starburst. The detailed morphology of the [FeII] 1.644 μm and emission Pa_α (at 1.87 μm) is revealed by the NICMOS images. The peak of the 2.2 μm continuum brightness(evolved population) lies very close to the dynamical centre. Most of the Pa_α emission (which traces the young population) is distributed in a ring of star formation (with a `hole' lacking line emission at the centre of the galaxy). These observations support the scenario in which the starburst in M82 is propagating outwards. It has long been suggested that the [FeII] emission in starburst galaxies can be used as a measure of supernova (SN) activity. M82 shows a large number of radio supernova remnants (SNRs), approximately 50, lying in the plane of the galaxy. The comparison of the positions of the bright compact [FeII] emitting regions with the location of the radio SNRs shows that there is no one-to-one spatial correspondence between the two emissions, suggesting that the radio and [FeII] emissions trace two populations of SNRs with different ages. Young (a few hundred years) SNRs are best traced by their radio emission, whereas the [FeII] stage lasts for at least a few 10⁴ yr. The compact [FeII] sources contribute only some 20 % of the total [FeII] emission observed in M82. However, much of the remaining unresolved [FeII] emission in the plane of the galaxy may arise from SNRs that expanded and merged into a general interstellar medium within a few 10⁴ yr. Presumably, as much as 70% of the total extinction-corrected [FeII]1.644 μm in M82 is associated with SNRs. The extended and diffuse [FeII] component in M82 seems to be related with the superwind above and below the disc of the galaxy. This revised version was published online in July 2006 with corrections to the Cover Date.     

Spectrographic study of Nova Cygni 1978 (V1668 CYG)

Nova Cygni 1978 was observed from October 11 to December 23, 1978 at the Beijing Observatory with the grating spectrograph attached to the Naismith focus of the Schmidt telescope. This paper gives postmaximum photographic magnitudes, identification of the spectral features, emission line structures, intensity ratios of some emission lines and the temperature of the underlying star.The main spectral lines in wavelength range from October 11 to 30 are those of the following atoms or ions: H, FeII, NII, TiII, [0I], NIII. From November 10, lines of [0III], HeI and Hell become visible one after the other. The emission line H_α shows three components of which the most redshifted is the strongest. In turn, each component is split into a number of secondary peaks. Temperature of the underlying star increases with decline of the nova brightness. The upper limit of temperature may be 120000 K.     

Spectroscopic observations of PU vulpeculae and its binary nature

The peculiar nova-like star PU Vul was observed spectroscopically from 1981 Sept 12 to 1983 Dec 11 at Yunnan Observatory and Beijing Observatory. In 1981 Sept, the star showed an absorption spectrum of the Balmer lines, the H,K and D lines, and some FeII, SrII and TiII lines. H was seen in emission in 1982 Oct and Hβ, in 1983 Sept. Both emissions were enhanced in 1983 Oct. and then dimmed since 1983 Nov. On 1983 Dec 11, Hβ might be absent, but the H was still visible. The spectral type was similar to that of an F giant during this period. This object may be an exceptionally slow nova and a binary consisting of an M giant and a hot companion.     

Age‐dating a star‐burst with GEMINI/CIRPASS observations of the core of M83

We present preliminary results from a set of near‐IR integral field spectroscopic observations of the central, star‐burst, regions of the barred spiral galaxy M83, obtained with CIRPASS on Gemini‐S. We present maps in the Paβ and [FeII] 1.257 μm emission lines which appear surprisingly different. We outline the procedure in which we will use Paβ emission line strengths and measures of CO absorption to determine the relative and absolute ages of individual star‐forming knots in the central kpc region of M83. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Spectral and photometric study of the symbiotic nova RS ophiuchus in quiet phase

The results of spectral and photometric study of the recurrent Nova RS Ophiuchus are presented and discussed. Observations were carried out in 2009–2016. During these eight years the fluxes of HI and FeII emission lines have slightly decreased by a factor of 3 - 4. Hα and Hβ exhibit double-peaked profiles with a central absorption. The ratio of the blue and red peaks intensities(V/R) varies from 0.3 to 1.0 for Hβ and from 0.4 to 0.7 for Hα. Possible correlations between changes of the ratio and other spectral parameters were investigated. Dependence of V/R on the radial velocity of absorbtion component is found out.     

The excitation of ionic lines and molecular bands in meteor wakes

The appearance of multiplets arising from the 4²P state of CaII (the H and K lines and an infrared triplet), the 1st positive band of N₂ and possibly certain multiplets of FeII in meteor wake spectra is explained semi-quantitatively in terms of the two-step sequence: collisional ionization of major atmospheric species O₂ and N₂ followed by resonant charge exchange with ablated meteoric atoms. Many other features which could arise through this mechanism (multiplets of MgII, SiII and FeII, and bands of O₂ and N₂) are likely to be weak or to have escaped detection owing to observational selection.     

Spectral variability of the peculiar A-type supergiant 3Pup

Optical spectra taken in 1997–2008 are used to analyze the spectral peculiarities and velocity field in the atmosphere of the peculiar supergiant 3 Pup. The profiles of strong Fe II lines and of the lines of other iron-group ions have a specific shape: the wings are raised by emissions, whereas the core is sharpened by a depression. The latter feature becomes more pronounced with the increasing line strength, and the increasing wavelength. Line profiles are variable: the magnitude and sign of the absorption asymmetry, and the blue-to-red emission intensity ratios vary from one spectrum to another. The temporal V_r variations are minimal for the forbidden emissions and sharp shell cores of the absorption features of FeII(42), and other strong lines of iron-group ions. The average velocity for the above lines can be adopted as the systemic velocity: V_sys = 28.5 ± 0.5 km/s. The weakest photospheric absorptions and photospheric MgII, Si II absorptions exhibit well-defined day-to-day velocity variations of up to 7 km/s. Quantitative spectral classification yields the spectral type of A2.7±0.3 Ib. The equivalent widths and profiles of Hδ and Hγ, and the equivalent width of the OI 7774 Å triplet yield an absolute magnitude estimate of Mv=?5.5^m ± 0.3^m, implying the heliocentric distance of 0.7 kpc.     

On correlation of Hα, iron and oxygen line strengths in some B, Be and shell stars

We present the equivalent width measurements of the hydrogen H _α line, the oxygen near-IR triplet OI 7772–5 Å\AA and of a number of FeII lines in several B, Be, and shell stars in optical and near-infrared regions. A study of the correlations between all these measured quantities has been made. The correlations of strength of lines with collected data of the near-IR color excess, the rotational velocity and the intrinsic polarization are also obtained and presented.     

Shocked molecular hydrogen in the LkHα234 region

We present near-IR images of the shocked gas in in HH 167 (the LkH234 jet) and HH 103. The H₂ 1-0 S(1) (2.122µm) and the 1.644µm [FeII] lines were observed. The relative spatial distribution of these two lines provides some insight into the nature of the shocks producing the objects.