... Credit Copyright: T. Puckett ( Puckett Observatory ) Explanation: This enhanced composite image detailing structure in the coma and dust tail of Hale-Bopp was recorded May 5 - one day before the comet's passage from north to south across the plane of Earth's orbit . ... Along with Southern Hemisphere observers, astronomers and a fleet of spacecraft of the International Solar-Terrestrial Physics program have been anxiously awaiting this north/south crossing. ... NASA Official: Jay Norris. ...

An Ancient Universe: How Astronomers Know the Vast Scale of Cosmic Time . THE CHANGING UNIVERSE: EVOLUTION HAPPENS! . b) Changes in Stars . One of the great discoveries of modern science is that stars (like people) live only a measurable life-time and then die. Although the lives of the stars are enormously longer than the span of a human life, we can learn about the life story of the stars by studying them at many different stages in their life cycle, from birth to death. ...

... Science Users Information > Observing Facilities > La Silla Facilities > La Silla Science Operations . ... La Silla News . ... Internal Pages . La Silla Science Operations Department (LSO) is part of the La Silla Paranal Observatory and is in charge of the operations of the telescopes on La Silla. ... In the La Silla Science Operation pages, you should find all the information you need for your observations from the time you have an idea of observations until when you finish processing your data. ...

... XMM-Newton SOC Home Page Conferences & Meetings . ... Data Analysis SAS News What is SAS? How to use SAS SAS Workshops SAS Version Changes Download and Install SAS Science Simulator (SciSim) . ... EPIC cameras optical loading . ... The PI is invited to cross-check the expected X-ray flux from the target source (and from any other potentially bright source in the target field of view), or to provide the SOC with her/his own estimate, if not originally specified in the proposal. ...

... 2006 October 28 . Comet SWAN Outburst . ... Explanation: Near its closest approach to planet Earth, comet SWAN (C/2006 M4) brightened unexpectedly earlier this week , becoming visible to naked-eye observers under dark night skies. ... To make the picture, images totaling eight minutes in exposure time were stacked and centered on the comet as it moved relatively quickly against the background star field. ... About APOD | ... NASA Web Site Statements, Warnings, and Disclaimers . ...

We model the spectral chanages of late oxygen-rich Miras observed in different pulsation phases. From a combination of variable near-IR spectra and UKIRT spectrophotometry of the 9.7 \mu m silicate dust emission feature in different phases we study the influence of the changing atmospherical circumstances on the conditions in the circumstellar dust shell. ... A comparision with the modelling results for another long period Mira U Ori is also provided. ...

... Observing . Observing details . ... Mike Keith has code to parse these schedules to produce a list of pulsar-specific Parkes observing. ... Please identify which observing sessions you can support and then click on "add new" on Mike's pulsar-specific schedule to add your name to the roster. ... Familiarise yourself with the current remote observing documentation listed below. ... The PPTA dashboard allows anyone to view the log from the current or any previous observing session: . ... PPTA log . ...

... Moon . ... What can astronomers tell us about the different colors on the surface of Jupiter's moon Europa? ... We can use the colors of Europa s surface to tell us about the chemical compounds that make up the surface and subsurface of the jovian moon. Even before the first spacecraft made a close visit to Europa, astronomers on Earth used telescopes to study the moon and were able to use a technique called spectroscopy to determine that Europa s surface is composed mostly of water ice. ...

... As part of the initial data delivery, the observer receives a package of so-called paper products , which are intended to provide a quick look at the data in hard-copy form. ... The information is presented in three separate tables: Target List, Observation List, and Observation Statistics. ... First, they do not have the visit-level summary of observations; some of the information is available via the tape log, but without any data quality flags or image statistics. ...

... 2000 June 21 . Solstice Celebration . ... Each individual image highlights a different temperature regime in the upper solar atmosphere and was assigned a specific color; red at 2 million, green at 1.5 million, and blue at 1 million degrees C. The combined image shows bright active regions strewn across the solar disk, which would otherwise appear as dark groups of sunspots in visible light images, along with some magnificent plasma loops and an immense prominence at the righthand solar limb. ...

... CIMAFITS is the name for the Arecibo FITS-file format. ... This is a list of (fairly) up-to-date documents describing CIMA and CIMAFITS: . The CIMA version history log which is the most up-to-date page listing all changes made to the different versions of CIMA . ... The CIMA user's log which chronologically lists changes made to CIMA that may be relevant to an observer. The CIMA engineering log which lists engineering changes made to CIMA that probably are of less interest to an observer. ...

... The most precisely determined characteristic for accreting neutron stars (NS's) is their period. ... Period changes show fluctuations. ... Some applications of stochastic processes in astrophysics especially in accreting systems were discussed in Lipunov (1987),Hoshino Takeshima (1993) and Lipunov (1992).In Hoshino Takeshima (1993) the authors, using simple models of MHD turbulence, try to explain aperiodic changes in X-ray luminosity of X-ray pulsars. ... Here, -constant angular momentum. ...

The "ring of fire" seen by satellite cameras around the polar caps (picture below) is probably created by electrons leaking from the tail's plasma sheet, whose magnetic field lines form a somewhat imperfect trap. ... One possible explanation involves the close association between auroral arcs and electric currents which flow along field lines between the ionosphere and distant space ( Birkeland currents ). ... That produces an extra resistance to the flow of current. ...

... Archives . ... Quote] Model Skeptics . ... From IMS Bulletin Vol. 36(7) p.10, TerenceтАЩs Stuff: Changing my mind (again) . Over the years IтАЩve had many strong likes and dislikes for the various parts our subject. ... IтАЩve been in love with sufficiency and hated cluster analysis. I thought the theory of games was elegant, while that of linear models lacked style. ... Brownian theory was hot, sampling theory was not. ... Comment ( RSS ) | ... Entries RSS . ... Chandra Blog . ML Theory . ...

Posting Observations . ... You will need to subscribe to vsnet-acc (to allow you access to post your observations). ... VSNet has several different e-mail sigs, and sub sigs. ... These list are controlled by a software package called " Majordomo ", which allows you to subscribe and unsubscribe yourself from these list with an e-mail message (automated). ... Once you have subscribed to vsnet-acc (which will only send you a welcome message back and nothing else) you can post to the other list. ...

Next: Mission Element Points-of-Contact . Previous: Mission Operations Data Transfer . ... Each mission element should ensure that their contact information remains current and notify the RSOG of any changes. ... Non-RSOG mission elements will also use the "dit" list to notify the RSOG (and all other mission elements) of unexpected events that may impact operations elsewhere, e.g., if a tracking station discovers that the spacecraft is in an unexpected configuration. ...

... Bad Astronomy . ... I think I will break from my usual format of Bad Astronomy/ Good Astronomy by saying that the way we define seasons currently is not strictly bad, but I feel (in my opinion!) that it could be better. The definition of when the seasons begin is at the moment of solstice or equinox; that is, winter (in the north) starts on December 22 nd and summer starts on June 22 nd . ... Now imagine breaking up the Sun's 46 degree up-and-down yearly swing into 1 day intervals. ...

Marc White . ... This page details the updates and changes I've made to this website since it's original iteration. ... The changes listed here are structural/design changes only. ... 29 Dec 2013 . ... Altered header/footer background colour, added header background image . ... E marc.white@anu.edu.au . ... F www.facebook.com/marc.white.au . L au.linkedin.com/pub/marc-white/84/460/84a/ . S marc.christopher.white . G github.com/marc-white . Design copyright Marc White 2014 . ...

CONTINUUM AND BROAD EMISSION LINE VARIABILITY OF SEYFERT GALAXIES V.T. Doroshenko1,2 , S.G. Sergeev2 , V.I. Pronik 1 2 Crimean Lab. of the Sternberg Astronomical Institute, Moscow University, Russia 2 Scientific-Research Institute, Crimean Astrophysical Observatory, Ukraine; p/o Nauchny, 98409, Crimea, Ukraine vdorosh@sai.crimea.ua We fo cused on the observed prop erties of some Seyfert galaxies without detailed discussion of underlying physical mechanisms. ...

... The most spectacular view however is from space, where large areas of aurora can be observed simultaneously, even the entire polar cap. ... Such pictures often show a continuous ring of aurora around the polar cap (picture above), caused mostly by electrons leaking out along magnetic field lines, from the plasma sheet of the Earth's magnetic tail. ... Field lines from the auroral oval are believed to lead to the plasma sheet. ... A near-Earth circular polar orbit has many uses. ...