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| Autor: | Ernst Pollmann [ 03. Juni 2007, 21:56:01 PM ] | ||
| Betreff des Beitrags: | gamma Cas | ||
An alle beteiligten Beobachter und sonst. Interessierten! Der derzeitige Anstieg der H-alpha EW von gamma Cas (siehe Anhang) wirft die Frage auf, ob dies so weitergehen wird. Ob da was Besonderes zu erwarten ist?
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| Autor: | Ernst Pollmann [ 05. Juni 2007, 10:09:47 AM ] |
| Betreff des Beitrags: | gamma Cas |
In einer eMail vom 05.06.2007 04:39:47 Westeuropäische Normalzeit schreibt Thom Gandet: Hi Ernst, Thank you for your e-mails about P Cyg and Gamma Cas. I told Arne Hended at AAVSO about the P Cyg results you sent out. He kindly e-mailed an AAVSO Special Alert on P Cyg. I forwarded your gamma Cas to him today. I think you guys are doing fantastic work! Has your group been observing Delta Sco? Cheers, Thom Gandet Hallo Liste, einige aktuelle Ergebnisse aus Gemeinschaftbeobachtungen unserer Gruppe zu gCas und PCyg hatte ich in der Be-Star-Mailingliste bekanntgegeben. Erfreulich und ermunternd ist das statement vom Profi Th. G. aus Südafrika (oben). ------ Start of attached email. Subject: Re: gamma Cas ------ Hi Ernst, Thank you for your e-mails about P Cyg and Gamma Cas. I told Arne Hended at AAVSO about the P Cyg results you sent out. He kindly e-mailed an AAVSO Special Alert on P Cyg. Here is what he wrote: "P Cyg (2014+37A) is the prototype of massive stars with high mass outflow; it is characterized by blue-shifted emission lines along with red-shifted absorption lines. Surprisingly, we've never created a Variable Star of the Season article for this neat star - I'll have to make sure that happens soon. "Located at 20:17:47.20 +38:01:58.5 J2000 it is typically around V=4.8 (though its outburst in AD1600 reached 3rd magnitude), and is the nearest of the Luminous Blue Variable (or S Dor) class, currently thought to be the progenitors to some types of supernovae. eta Car is another example. "P Cyg also has a weakly visible surrounding nebulae of about 3arcmin diameter, and an inner nebulae about 20arcsec diameter. "Lamers and de Groot (1992, A&A 257, 153) also indicate that P Cyg has been slowly increasing in mean brightness over the past few centuries, at a rate of about 0.15mag per century. Recently, P Cyg has also been showing increased H-alpha activity, as observed by Ernst Pollman, a German spectroscopist. "Since P Cyg is an ideal target for the AAVSO PEP observers, I would like to ask them to give P Cyg high priority in their monitoring activity over the current season. You can find the PEP chart on the web page, including the suggested comparison and check star. There are no nearby comp stars for CCD observers, but those with wide-field systems could also give this a try. This remains an interesting target for visual observers as well; the increased activity could be a precursor for an outburst. Arne" I forwarded your gamma Cas to him today. I think you guys are doing fantastic work! Has your group been observing Delta Sco? Cheers, Thom Gandet ----- Original Message ----- From: "Ernst Pollmann" To: <BE-STARS@...> Sent: Monday, June 04, 2007 11:45 AM Subject: gamma Cas What happens in gamma Cas since one year? Since June 2006 more or less constantly increase of its Halpha EW of 10 Angströms (see attachment). The plot represent amateur measurements of the spectroscopy group of the German Amateur Astronomers Society (VdS). Ernst Pollmann Emil-Nolde-Str. 12 51375 Leverkusen Phone: 0049-214-91829 http://spektroskopie.fg-vds.de/pollmann ------ End of attached email ------ |
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| Autor: | Roland Bücke [ 05. Juni 2007, 21:42:21 PM ] |
| Betreff des Beitrags: | |
Hallo Ernst, leider ist gamma Cas für mich noch nicht wieder erreichbar. In ein paar Wochen sollte es in der zweiten Nachthälfte aber möglich sein. Die Entwicklung der EW ist spannend. Auffallend ist, dass der Anstieg bei meinen Beobachtungen wesentlich schwächer verläuft. Ich habe dafür momentan noch keine Erklärung. Viele Grüße Roland |
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| Autor: | Roland Bücke [ 21. Juni 2007, 21:29:46 PM ] |
| Betreff des Beitrags: | |
Hallo Ernst, am 19.06.07 konnte ich gamma Cas wieder mal beobachten. Den rapiden Anstieg der EW kann ich mit meiner Beobachtung nicht bestätigen: 19.06.07, JD 2454271.5, EW = -32,33 +/-0.09 (aus 9 Wiederholungsmessungen mit Vertrauensniveau von 68,3%) Beste Grüße Roland |
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