First release of the IPHAS catalogue of new extended planetary nebulae

Date of Acceptance: 30/06/2014We present the first results of our search for new, extended planetary nebulae (PNe) based on careful, systematic, visual scrutiny of the imaging data from the Isaac Newton Telescope Photometric Ha Survey of the Northern Galactic plane (IPHAS). The newly uncovered PNe will help to improve the census of this important population of Galactic objects that serve as key windows into the late-stage evolution of low- to intermediate-mass stars. They will also facilitate study of the faint end of the ensemble Galactic PN luminosity function. The sensitivity and coverage of IPHAS allows PNe to be found in regions of greater extinction in the Galactic plane and/or those PNe in a more advanced evolutionary state and at larger distances compared to the general Galactic PN population. Using a set of newly revised optical diagnostic diagrams in combination with access to a powerful, new, multiwavelength imaging data base, we have identified 159 true, likely and possible PNe for this first catalogue release. The ability of IPHAS to unveil PNe at low Galactic latitudes and towards the Galactic Anticentre, compared to previous surveys, makes this survey an ideal tool to contribute to the improvement of our knowledge of the whole Galactic PN population.Peer reviewe

PENGARUH TERPAAN BERITA PERKOSAAN DI TRIBUNNEWS.COM TERHADAP SIKAP WASPADA MAHASISWI

The research problem in this research includes whether there is the influence of rape news of UGM female student in Tribunnews.com towards female students vigilant attitude in interact and how the influence imposed. Variable X in this research is rape news, while vigilant attitude of female students in interact is variable Y. Quantitative research is implemented by means of associative type. In addition, the basic research is survey method. The population in this study is female students second period of KKN 2018/2019 University of Muhammadiyah Malang and 36 of them become the research sample. Questionnaires and documentation are implemented as data collection techniques. Validity and reliability test are also implemented as the research instrument test. Furthermore, the researcher conducts simple linear regression and hypothesis testing using the t test as data analysis techniques. The coefficient of variable X is 0.716 (positive). From the analysis results obtained that R square result (the coefficient of determination) is 0.130. R value (the correlation coefficient) is 0.361, it shows the correlation between news rape of UGM female student in Tribunnews.com towards female students vigilant attitude in interact (Y) are included in a weak category. On the other hand, t table (α = 0.05; df residual = 34) is 1.690. Since t arithmetic > t table is 2.255 > 1.690 or sig. t value (0.031) < α = 0.05, the influence of X (rape news of UGM female student in Tribunnews.com) towards Y (female students vigilant attitude in interact) is significant. In accordance with the analysis above, it can be concluded that 13% of female students vigilant attitude in interact variable (Y) is influenced by independent variable, namely rape news of UGM female student in Tribunnews.com, and yet 87% of female students vigilant attitude in interact variable is influenced by other variables

The post-common-envelope binary central star of the planetary nebula Ou 5: a doubly-eclipsing post-red-giant-branch system

We present a detailed study of the stellar and orbital parameters of the post-common envelope binary central star of the planetary nebula Ou 5. Low-resolution spectra obtained during the primary eclipse – to our knowledge the first isolated spectra of the companion to a post-common-envelope planetary nebula central star – were compared to catalogue spectra, indicating that the companion star is a late K- or early M-type dwarf. Simultaneous modelling of multi-band photometry and time-resolved radial velocity measurements was then used to independently determine the parameters of both stars as well as the orbital period and inclination. The modelling indicates that the companion star is low mass (∼0.25 M⊙) and has a radius significantly larger than would be expected for its mass. Furthermore, the effective temperature and surface gravity of nebular progenitor, as derived by the modelling, do not lie on single-star post-AGB evolutionary tracks, instead being more consistent with a post-RGB evolution. However, an accurate determination of the component masses is challenging. This is principally due to the uncertainty on the locus of the spectral lines generated by the irradiation of the companion’s atmosphere by the hot primary (used to derive companion star’s radial velocities), as well as the lack of radial velocities of the primary

Author Correction: The messy death of a multiple star system and the resulting planetary nebula as observed by JWST

Stars and planetary system

IPHAS and the symbiotic stars . II. New discoveries and a sample of the most common mimics

Contains fulltext : 84417.pdf (preprint version ) (Open Access) Contains fulltext : 84417.pdf (publisher's version ) (Open Access

A Search for New Planetary Nebulae Located at Large Galactocentric Distances

Original paper can be found at: http://aspbooks.org/a/volumes Copyright Astronomical Society of the PacificWe introduce the new Galactic Plane Hα survey IPHAS, present our PNe selection method, and discuss two examples of very distant new PNe

Automatic spectral classification of stellar spectra with low signal-to-noise ratio using artificial neural networks

Context. As part of a project aimed at deriving extinction-distances for thirty-five planetary nebulae, spectra of a few thousand stars were analyzed to determine their spectral type and luminosity class. Aims. We present here the automatic spectral classification process used to classify stellar spectra. This system can be used to classify any other stellar spectra with similar or higher signal-to-noise ratios. Methods. Spectral classification was performed using a system of artificial neural networks that were trained with a set of line-strength indices selected among the spectral lines most sensitive to temperature and the best luminosity tracers. The training and validation processes of the neural networks are discussed and the results of additional validation probes, designed to ensure the accuracy of the spectral classification, are presented. Results. Our system permits the classification of stellar spectra of signal-to-noise ratio (S/N) significantly lower than it is generally considered to be needed. For S/N 20, a precision generally better than two spectral subtypes is obtained. At S/N < 20, classification is still possible but has a lower precision. Its potential to identify peculiar sources, such as emission-line stars, is also recognized. Zapotitlán ESO, 2012

Distance determination to PNe using the extinction-distance method

We present individual distances to three PNe: NGC 6537, NGC 6781 and NGC 7027, determined by the extinction-distance method. These objects are part of a larger sample (35) of PNe that we observed at ORM. In order to apply this method, and to obtain accurate distances, we determined the spectral type of 40 to 60 stars in the line of sight of each PNe. This implied the necessity of classifying few thousands of stellar spectra with S/N ratio between 10 and 60. To solve such need we developed an ANN system to perform automatic spectral classification which could classify spectra with S/N ratio as low as 20 with an accuracy better than 2 spectral subtypes. In this poster we compare the accuracy of such distances with previous distance determinations using other methods. We conclude that it is possible to use this method to obtain the distance of a large number of PNe with better precision. © 2012 International Astronomical Union

IPHAS and the symbiotic stars 1: selection method and first discoveries

Peer reviewe

The ongoing outburst of the new symbiotic star IPHASJ190832.31+051226.6

Original article can be found at: http://www.aanda.org/ Copyright The European Southern Observatory (ESO)Aims. Eleven new symbiotic stars have recently been discovered with IPHAS, the INT Hα survey of the Northern Galactic plane. The star IPHAS J190832.31+051226.6 was proposed as an additional candidate on the basis of the existing spectrum. Here, we investigate the nature of this source by means of additional observations. Methods. Photometric data, optical spectra obtained in 2006 and 2009, a higher resolution spectrum resolving the Hα profile, and near-IR spectra of IPHAS J190832.31+051226.6 are all presented. Results. The source brightened in the r band by 2.3 mag from 2004 to 2009. From 2006 to 2009, the spectrum has evolved from one with the obvious continuum of an M giant star plus HI and HeI lines in emission to a lower excitation nebular spectrum with HI, CaII, and FeII emission and a bluer continuum in which the absorption bands of the red giant are only visible at wavelengths longer than 7500 Å. The Hα line is broad with a deep central absorption and extended wings. Conclusions. The averaged rate of the brightness increase, the rise of a blue continuum overwhelming the absorption bands of the M giant, and the corresponding decline of the ionization condition of the emission-line spectrum, are all consistent with the hypothesis that IPHAS J190832.31+051226.6 is a new symbiotic star picked up during the onset of a symbiotic nova outburst that is still in progress at the time of writing.Peer reviewe