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The id. on the RASNZ charts, and Guide8 (for example) is correct. T CMa = CoD-25 4409 (9.7) = CPD-25 2242 (9.4). The strange thing is that, according to Tycho-2, it has very little colour (B-V =0.16). This is very odd for a semi-regular variable. It is also surprising that no spectrum is available for a variable which has been known for many, many decades and stays relatively bright. Truly a neglected variable, and, one suspects, a misidentified one. Regards, Mati morel@ozemail.com.au ----- Original Message ----- From: Peter F. Williams To: vsnet chat Cc: Janet Mattei Sent: Saturday, July 05, 2003 5:36 PM Subject: [vsnet-chat 6621] T CMa Identification Question Hello All, Over the last several years I have made scattered observations of the SR variable T CMa. This star is plotted on VSS RASNZ charts 987/988 for VY CMa and has a catalogue range of 9.5 to 11 and period 309 days but no spectrum indicated. My observations have shown little variation, ranging between 11.2 and 12.0. Intrigued by a lack of variation in my observations, I recently checked both the vsnet and AAVSO light curves for T CMa and was surprised to find it being recorded by other observers mostly between magnitudes 9 and 9.5. A check of the AAVSO chart for VY CMa shows T CMa plotted but this chart does not plot a magnitude 9.2 field star 2 arcmin SW of the variable. This chart is probably not intended for observing T CMa and I suspect the observations in both the vsnet and the AAVSO refer to the field star and not T CMa. If my suspicians are correct, this still leaves a question over the true variations of T CMa. Regards Peter Williams Heathcote NSW
Return to the Powerful Daisaku Nogami
vsnet-adm@kusastro.kyoto-u.ac.jp
