wpo - session spectra

Each spectrum occupies partially about 2 - 3 row of pixels across the CCD and has been electronically stretched here via PaintShop Pro 4. Alternatively they are displayed as intensity profiles.

Virtually all the spectra are via the Rainbow diffraction grating placed about 20mm in front of the CCD chip, like a filter in the convergent beam of my 30cm Meade LX200 telescope.  The vertical line [zero order image to the left] is the star's real image and acts as a fixed reference for estimating line wavelengths etc. - no two stars' spectra are identical.  The spectral resolution of 3nm to 5nm/pixel is classified as very low but can penetrate to mag 14 in about 5 minutes exposure or snap a bright star in 1/100 second.

From 2003 July spectra at 0.7A [7A] resolution included via the WPO spectrograph covering about a third of the visual spectrum in red light with B band head used as a fixed reference.  Stars to ~ mag 7-8 recorded in 120s exposure.

Email=mgavin[at]ntlworld.com Session spectra 1999 Mar 18+26 here  1999 June 8/9 1999 June 15/16 1999 June 21/22 1999 June 24/25 1999 Aug 16 1999 Dec 27-29 2000 Jan 4 2000 Mar 10 2000 Aug 5 2001 Oct 15+28 2002 Jan 28 2002 Jan 29/30 2002 Mar 27 2002 Sept 23-30 2002 Oct 18 2003 Feb 2003 July A 2003 July B 7A res 2003 July C 7A res 2003 July 25/27 7A 2003 Aug 14 50A 2003 Aug-Oct 25A 2003 Nov 2003 Dec 2004 Jan 2004 Apr 2004 May OG spectra 2004 May/June 2004 Aug 2003 June Polaris 7A res 2003 June - Foth stellar 2003 May Ebert solar 2003 June - grism solar 2003 July-Oct LXCyg 2003 June - Tessar stellar General spectroscopy main page PN spectra WR stars click for homepage

1999 Mar 26 - WPO is sited 10 miles south of central London so looking due north has been a permanent 'no-no' due to the horrendous light pollution in that direction up to 40o altitude. An experiment to find T Cep (below Polaris) was tried in good transparency but under a gibbous moon. Although nothing could be seen in the visual finder it worked amazingly well with stars down to just 20o of the northern horizon clearly recorded - opening up a whole zone of circumpolar stars from WPO! Some of the stars were very low in the 'London murk' and these spectra could be improved.         1999 Mar 18 -  following selection captured during a two and half hour session in poor transparency (lvm~3) in a southerly direction. Note the 'carbon' stars T Cnc and RV Mon have a triple absorption band between A line and Ha. The top pair (RZ Hya+W Cnc) are very faint currently (2m exposure) and their spectra is almost entirely in IR (to right). Compare RZ Hya to brighter S Hya (15s exposure) - both are of similar spectra class but presumably at different parts of the light cycle. S Hya and Betelgeuse (alpha Ori) currently have similar spectra although of somewhat different spectral class. Note the brevity of the Betelgeuse exposure (1/100 second !) enabling fainter stars' spectra to be captured in a few seconds exposure.