7 research outputs found

    M31N 2007-11d: A Slowly-Rising, Luminous Nova in M31

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    We report a series of extensive photometric and spectroscopic observations of the luminous M31 nova M31N 2007-11d. Our photometric observations coupled with previous measurements show that the nova took at least four days to reach peak brightness at R~14.9 on 20 Nov 2007 UT. After reaching maximum, the time for the nova to decline 2 and 3 magnitudes from maximum light (t_2 and t_3) was ~9.5 and ~13 days, respectively, establishing that M31N 2007-11d was a moderately fast declining nova. During the nova's evolution a total of three spectra were obtained. The first spectrum was obtained one day after maximum light (5 days post-discovery), followed by two additional spectra taken on the decline at two and three weeks post-maximum. The initial spectrum reveals narrow Balmer and Fe II emission with P Cygni profiles superimposed on a blue continuum. These data along with the spectra obtained on the subsequent decline clearly establish that M31N 2007-11d belongs to the Fe II spectroscopic class. The properties of M31N 2007-11d are discussed within the context of other luminous novae in M31, the Galaxy, and the LMC. Overall, M31N 2007-11d appears to be remarkably similar to Nova LMC 1991, which was another bright, slowly-rising, Fe II nova. A comparison of the available data for luminous extragalactic novae suggest that the >~4 day rise to maximum light seen in M31N 2007-11d may not be unusual, and that the rise times of luminous Galactic novae, usually assumed to be <~2 days, may have been underestimated.Comment: Accepted for publication in The Astrophysical Journal (28 pages, 6 figures

    The elastodynamic Green's tensor for the 2D half-space

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    Alcohol and its effects on sprint and middle distance running.

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    Alcohol has been used as an aid to performance for a considerable period of time in many athletic endeavours. Five sprinters and five middle distance athletes were tested to determine whether differing levels of alcohol (0.01 mg X ml-1, 0.05 mg X ml-1 and 0.10 mg X ml-1) had differing effects upon performance times in the 100 m, 200 m, 400 m, 800 m and 1500 m events. Blood alcohol concentration (BAC) was estimated from breath alcohol concentration (BrAC) using a hand held Drager Alcotest 7310 and a Borkenstein Breathalyser. Alcohol affected all but the 100 m event to varying degrees. In the 200 m the performance decreased when the level of intoxication increased. This was not the case in the 400 m which showed a difference between the two lower levels of alcohol consumption (0.01 mg X ml-1 to 0.05 mg X ml-1) but not between the 0.05 mg X ml-1 and 0.10 mg X ml-1. In the middle distance events the 800 m was most adversely affected. We concluded that alcohol is not an ergogenic aid in so much that it does not improve performance. In the 100 m events, performance remained stable. More research in this area is warranted
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