Observing Notes - Visual sighting of SN 2011dh in M51 on June 8 4UT-10UT at SPOC
On the night and morning of June 7-June 8 local time, I used the SPOC 16 inch Ealing to visually acquire SN 2011dh in M51 (distance-then of about 27 million light-years). Also at SPOC last night were Roger Fry, using the 32 inch Grim scope for a training session for two attendees (I do not have my slip of paper with their names on it with me), one visiting family, and Joe Bauman, using his personal Meade LX200 10 inch. All reported being able to see SN 2011dh in M51 at the location illustrated in Tyler Allred's recent image at url http://www.allred-astro.com/gpage8.html . Visually, the supernova appeared as a distinct, but unusually small, stellar point source within one of the nebulous arms of M51. Although seeing was excellent, at times this stellar point would dissolve into a fuzzy nebular patch between mag. 13 and 14. There also is a bright HII nebular area and star cluster 4 or 5 arcsecs celestial southeast of this supernova - designated L2000-899 and 911 in the Simbad system (Larsen 2000). Other designations for these bright regions include 2MASXi J1330024+470948. Visual 15.03 magnitude star 3UC 275-121849 is almost near the nova's position. Both of the cluster-HII regions can be easily seen in the Hubble M51 reference image, url http://en.wikipedia.org/wiki/File:Messier51_sRGB.jpg . The nova could be seen even under skies partially washed out by a waxing crescent moon. After moon set and between between 1 and 2 am local time, Patrick stopped by for a visit. On examining the Ealing eyepiece view, he properly questioned whether we had actually seen the supernovae since recent reports placed the nova at magnitude 14 and below the current limiting magnitude of the Ealing. The supernovae was very faint pinpoint of light much less visually distinct than suggested by Tyler's infrared light sensitive CCD image. On comparing a planetarium program chart with a UC3 catalogue down to magnitude 18, the eyepiece view and Tyler's image, I concluded that we were visually seeing the supernova, based on the following: 1) Checking the AAVSO light curve for SN 2011dh this afternoon, the nova has brightened to visual magnitude 13.3. 2) Nearby (within 30 arcminute) 12.1 magnitude star TYC 3463-348-1 and visual magnitude 13.74 star 3UC 275-121870 were visible in the eyepiece. A Milky Way foreground star in M51, 3UC 275-121833, at V magnitude 13.58 was also a visible. 3) Nearby 14.3 magnitude star 3UC 275-121833 was not visible. I prepared a chart of the above stars for reference at url - http://www.slas.us/gallery2/main.php?g2_itemId=4363 . The AAVSO photometry chart for sn2011dh can be found at url - http://www.aavso.org/vsp/chart/pl/4931BMM . A general photometry reference chart by the Supernova Network by Odd Trondal is available at url - http://www.supernovae.net/snimages/reference/n5194.jpg . Updated AAVSO photometry reports for sn2011dh can be found through the AAVSO ``Quick Look'' table by entering ``sn 2011dh'' into the first question box ``WHAT IS THE NAME, DESIGNATION, OR AUID OF THE OBJECT?'' at url - http://www.aavso.org/ql - and hitting the ``Search'' button. 27 million years ago during the Oligocene period, Utah was undergoing a period of active volcanoes and uplift of the Unita basin and Colorado Plateau region. http://geology.utah.gov/utahgeo/geo/geohistory2.htm . On closing the Ealing around 2:00am, I spent some time star hopping with 10x50 binoculars. All clouds cleared out except a small band on the northeast horizon, atmospheric moisture dropped, and the skies above SPOC reached down to the point where distinguishing constellations became difficult. The disk of the Milky Way had risen to about 45 degrees altitude - its autumn position - and stretched perpendicular from the southern to northern horizons. The Cygnus dark cloud lanes were easily seen. My estimate is this was a mag. 5.6 to 5.8 sky. I spent 45 minutes reviewing a basic Messier series from the southern horizon with GC M4 and Ptolemy's cluster (M7), through M24 and M11 in Scutum, across Alberio, and ending with Perseus Double Cluster and the alpha Perseus OB Association low on the northern horizon. It was a magical morning that allowed me to due a quick annual binocular all-summer-sky review, and I was grateful not to have pending work obligations would prevent me from staying up all night. Joe and I separately noticed two or three bright meteors around mag 2-3 between 2 and 3am, which corresponds to the general Antihelion shower on the IMO current meteor activity report. Clear Skies - Kurt Larsen, S.S. 2000. Young massive star clusters in M 51. MNRAS. 319:893-901. L2000-899 in http://simbad.u-strasbg.fr/simbad/sim-id?Ident=[L2000]++899&NbIdent=1
Nice report, Kurt -- it's nitpicky but my Meade is a 12". Thanks, Joe ________________________________ From: Canopus56 <canopus56@yahoo.com> To: Utah Astronomy List Serv <utah-astronomy@mailman.xmission.com> Sent: Wednesday, June 8, 2011 7:38 PM Subject: [Utah-astronomy] Observing Notes - Visual sighting of SN 2011dh in M51 on June 8 4UT-10UT at SPOC On the night and morning of June 7-June 8 local time, I used the SPOC 16 inch Ealing to visually acquire SN 2011dh in M51 (distance-then of about 27 million light-years). Also at SPOC last night were Roger Fry, using the 32 inch Grim scope for a training session for two attendees (I do not have my slip of paper with their names on it with me), one visiting family, and Joe Bauman, using his personal Meade LX200 10 inch. All reported being able to see SN 2011dh in M51 at the location illustrated in Tyler Allred's recent image at url http://www.allred-astro.com/gpage8.html . Visually, the supernova appeared as a distinct, but unusually small, stellar point source within one of the nebulous arms of M51. Although seeing was excellent, at times this stellar point would dissolve into a fuzzy nebular patch between mag. 13 and 14. There also is a bright HII nebular area and star cluster 4 or 5 arcsecs celestial southeast of this supernova - designated L2000-899 and 911 in the Simbad system (Larsen 2000). Other designations for these bright regions include 2MASXi J1330024+470948. Visual 15.03 magnitude star 3UC 275-121849 is almost near the nova's position. Both of the cluster-HII regions can be easily seen in the Hubble M51 reference image, url http://en.wikipedia.org/wiki/File:Messier51_sRGB.jpg . The nova could be seen even under skies partially washed out by a waxing crescent moon. After moon set and between between 1 and 2 am local time, Patrick stopped by for a visit. On examining the Ealing eyepiece view, he properly questioned whether we had actually seen the supernovae since recent reports placed the nova at magnitude 14 and below the current limiting magnitude of the Ealing. The supernovae was very faint pinpoint of light much less visually distinct than suggested by Tyler's infrared light sensitive CCD image. On comparing a planetarium program chart with a UC3 catalogue down to magnitude 18, the eyepiece view and Tyler's image, I concluded that we were visually seeing the supernova, based on the following: 1) Checking the AAVSO light curve for SN 2011dh this afternoon, the nova has brightened to visual magnitude 13.3. 2) Nearby (within 30 arcminute) 12.1 magnitude star TYC 3463-348-1 and visual magnitude 13.74 star 3UC 275-121870 were visible in the eyepiece. A Milky Way foreground star in M51, 3UC 275-121833, at V magnitude 13.58 was also a visible. 3) Nearby 14.3 magnitude star 3UC 275-121833 was not visible. I prepared a chart of the above stars for reference at url - http://www.slas.us/gallery2/main.php?g2_itemId=4363 . The AAVSO photometry chart for sn2011dh can be found at url - http://www.aavso.org/vsp/chart/pl/4931BMM . A general photometry reference chart by the Supernova Network by Odd Trondal is available at url - http://www.supernovae.net/snimages/reference/n5194.jpg . Updated AAVSO photometry reports for sn2011dh can be found through the AAVSO ``Quick Look'' table by entering ``sn 2011dh'' into the first question box ``WHAT IS THE NAME, DESIGNATION, OR AUID OF THE OBJECT?'' at url - http://www.aavso.org/ql - and hitting the ``Search'' button. 27 million years ago during the Oligocene period, Utah was undergoing a period of active volcanoes and uplift of the Unita basin and Colorado Plateau region. http://geology.utah.gov/utahgeo/geo/geohistory2.htm . On closing the Ealing around 2:00am, I spent some time star hopping with 10x50 binoculars. All clouds cleared out except a small band on the northeast horizon, atmospheric moisture dropped, and the skies above SPOC reached down to the point where distinguishing constellations became difficult. The disk of the Milky Way had risen to about 45 degrees altitude - its autumn position - and stretched perpendicular from the southern to northern horizons. The Cygnus dark cloud lanes were easily seen. My estimate is this was a mag. 5.6 to 5.8 sky. I spent 45 minutes reviewing a basic Messier series from the southern horizon with GC M4 and Ptolemy's cluster (M7), through M24 and M11 in Scutum, across Alberio, and ending with Perseus Double Cluster and the alpha Perseus OB Association low on the northern horizon. It was a magical morning that allowed me to due a quick annual binocular all-summer-sky review, and I was grateful not to have pending work obligations would prevent me from staying up all night. Joe and I separately noticed two or three bright meteors around mag 2-3 between 2 and 3am, which corresponds to the general Antihelion shower on the IMO current meteor activity report. Clear Skies - Kurt Larsen, S.S. 2000. Young massive star clusters in M 51. MNRAS. 319:893-901. L2000-899 in http://simbad.u-strasbg.fr/simbad/sim-id?Ident=[L2000]++899&NbIdent=1 _______________________________________________ Utah-Astronomy mailing list Utah-Astronomy@mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy Visit the Photo Gallery: http://www.slas.us/gallery2/main.php
participants (2)
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Canopus56 -
Joe Bauman