David's Astronomy Pages
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 Images (S315) |
 Images Sessions |
Home Page |
 Images (S317) |
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Objects Session Notes
CY Lyr - Variable Star (Type UGSS) HX Peg - Variable Star (Type NL) Epsilon Aurigae - Variable Star (Type EA/GS) Zeta Aurigae - Variable Star (Type EA/GS) Eta Aurigae - Star Astrometric & Photometric Monitoring - SS Cyg (dwarf nova)
- U And (mira variables)
- BL Lac (blazar)
- GP And, RX And, Z And, R CrB, CI Cyg, CY Lyr, RU Peg, HX Peg, Per DY, Per GK, Sge FG, Sge U, Sge V (variables)
- Ross 248, Cyg 61, Groombridge 34 (Nearby Stars)
- WZ Sge attempt (failed due to poor sky conditions)
- Late evening session (3.4 hrs), clouding over towards end of session. - Ambient Temperature 3.0 degC (minimum), rising to 5 degC as cloud developed. - CCD operation of -20 degC
(at 64% average cooling).- main objective of the session was to acquire images of key selected stars for ongoing photometric and astrometric analysis. - secondary objective was to take baseline images of two stars in Auriga, that we both have eclipses in 2009 (Epsilon Aur & Zeta Aur) -
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CY Lyr (Lyra) - Image taken
with C Filter |
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Annotated CCD Image 3 x 180s sec exposure (average combine), 2x2 binning, C Filter 2006-10-18 21:23 h UT (#316149-51) |
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| HX Peg (Pegasus) Catalog mag range +12.9 to +16.6 HX Peg is visible on left hand side of the image below Estimated mag +14.5 (star is not visible on 30s V,R images - requires longer exposure) |
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CCD Image 3 x 30s exposure (average combine), 2x2 binning, C Filter 2008-10-18 21:54 hUT (#316174-80) |
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Epsilon Aurigae is the longest period eclipsing binary known with a period of 27.1 years. The exact nature of this system is still not fully understood. With such a long period the actual eclipse would be expected to be short, but is just the opposite – lasting nearly 2 years. This means the eclipsing body is gigantic (by some estimates over 2,000 solar radii). During the middle of the eclipse there is an unexpected eclipse brightening. There appears to be a hole in the center of this object. To add to the mystery the secondary object does not appear to have a spectrum of its own. Only the primary star's spectrum can be seen. During the eclipse the system's light is reduced the same at all wavelengths. It is as if there is a giant neutral density filter with a hole in the middle is passing in front of the primary star. Eclipses of Eps Aur are superimposed upon a background of 0.2 mag variations (0.17 in V, 0.23 in B)
| Eps Aur (Auriga) Epsilon Aurigae is an unusual eclipsing binary with a period of 27.08 years. (Catalog mag range +2.92 to +3.83) It is due to be in eclipse in 2009-2011 with ingress starting on around 2009-08-06 The eclipse will be the subject of significant interest to astronomers [ Epsilon Aurigae Eclipse Campaign Homepage ] Eps Aur is the bright star in centre of image. There are no suitable comparison stars in the same field. Photometry will therefore need to involve alternating slewing to and from a suitable comparison star. The brightest control star is about 5.5 mag dimmer than Eps Aur and may be difficult to reliably image in B, V filters |
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CCD Image 10s exposure, 2x2 binning, C Filter 2008-10-18 23:10 hUT (#316279) |
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| Zet Aur (Auriga) Zeta Aurigae is an eclipsing binary with a period of 972 days. (Catalog mag range +3.70 to +3.97) The star is due to enter eclipse on 2009-03-02, with mid eclipse on 2009-03-22 and end eclipse on 2009-04-07. Zet Aur is the bright star in centre of image. There are no suitable comparison stars in the same field. Photometry will therefore need to involve alternating slewing to and from a suitable comparison star. Brightest control star is about 6.5 mag dimmer than Zet Aur and may be difficult to reliably image in B, V filters |
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CCD Image 10s exposure, 2x2 binning, C Filter 2008-10-18 23:13 hUT (#316286) |
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| Eta Aur (Auriga) Eta Aurigae is a potential comparison star for both Epsilon and Zeta Aurigae However it is itself a suspected variable (NSV1822) with suspected variation of 0.03 mag (NSV Catalog mag range +3.16 to +3.19) Eta Aur is the bright star in centre of image. Image is affected by thin cloud. |
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CCD Image 10s exposure, 2x2 binning, C Filter 2008-10-18 23:36 hUT (#316315) |
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Images collected for Astrometric Monitoring
of Nearby Stars Project
Images collected for Photometric Monitoring
of Variable Stars
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| This Web Page: | CCD Images - Session 316 (2008-10-18) |
| Last Updated : | 2015-05-16 |
| Site Owner : | David Richards |
| Home Page : | David's Astronomy Web Site |
