论文标题
$ ubv $颜色的颜色演变。 iv。时间拉伸$（u-b）_0 $ - $（m_b-2.5 \ log f _ {\ rm s}）$和$（v-i）_0 $ - $ - $ - $（m_i-2.5 \ log f _ {\ rm s}）
The $UBV$ Color Evolution of Classical Novae. IV. Time-Stretched $(U-B)_0$-$(M_B-2.5\log f_{\rm s})$ and $(V-I)_0$-$(M_I-2.5\log f_{\rm s})$ Color-Magnitude Diagrams of Novae in Outburst
论文作者
论文摘要
如果我们正确挤压或拉伸目标NOVA的时间尺度，则两个古典Novae的光曲线和颜色演变可能会重叠。然后，目标NOVA的亮度与模板Nova的亮度相关，$（m [t]）_ {\ rm template} =（m [t/f _ {\ rm s}] - 2.5 \ log f _ {\ log f _ {\ rm s}） $ f _ {\ rm s} $是目标和模板Novae之间的时间尺度的比率。在本系列的先前论文中，我们表明许多Novae在时间伸展的$（B-V）_0 $ - $（M_V-2.5 \ log f _ {\ rm S}）$ color-magnitude图中广泛重叠。在本文中，我们提出了另外两个$（u-b）_0 $ - $（m_b-2.5 \ log f _ {\ rm s}）$和$（v-i）_0 $ - $ - $ - $（m_i-2.5 \ log f _ {\ rm s}） Here, $(U-B)_0$, $(B-V)_0$, and $(V-I)_0$ are the intrinsic $U-B$, $B-V$, and $V-I$ colors and not changed by the time-stretch, and $M_B$, $M_V$, and $M_I$ are the absolute $B$, $V$, and $I$ magnitudes.使用这些属性，我们大大完善了先前的距离估计值和红色的估计。获得的距离与{\ it Gaia}数据发布2目录的距离是合理的一致性。
Light curves and color evolutions of two classical novae can be largely overlapped if we properly squeeze or stretch the timescale of a target nova against that of a template nova by $t'=t/f_{\rm s}$. Then the brightness of the target nova is related to the brightness of the template nova by $(M[t])_{\rm template} = (M[t/f_{\rm s}] - 2.5 \log f_{\rm s})_{\rm target}$, where $M[t]$ is the absolute magnitude and a function of time $t$, and $f_{\rm s}$ is the ratio of timescales between the target and template novae. In the previous papers of this series, we show that many novae broadly overlap in the time-stretched $(B-V)_0$-$(M_V-2.5 \log f_{\rm s})$ color-magnitude diagram. In the present paper, we propose two other $(U-B)_0$-$(M_B-2.5\log f_{\rm s})$ and $(V-I)_0$-$(M_I-2.5\log f_{\rm s})$ diagrams, and show that their tracks overlap for 16 novae and for 52 novae, respectively. Here, $(U-B)_0$, $(B-V)_0$, and $(V-I)_0$ are the intrinsic $U-B$, $B-V$, and $V-I$ colors and not changed by the time-stretch, and $M_B$, $M_V$, and $M_I$ are the absolute $B$, $V$, and $I$ magnitudes. Using these properties, we considerably refine the previous estimates of their distance and reddening. The obtained distances are in reasonable agreement with those of {\it Gaia} Data Release 2 catalogue.
