银河系中一颗超亮新星的证认：重新分析候选新星CP Lac、CP Pup、V838 Her、V597 Pup、V5583 Sgr和V5589 Sgr的光变曲线
Identification of a superbright nova in our Galaxy: revisiting the light curve analyses of the candidate novae CP Lac, CP Pup, V838 Her, V597 Pup, V5583 Sgr, and V5589 Sgr
AI总结：
本研究通过对比模型光变曲线分析6颗候选新星，证认V838 Her为超亮新星，其余5颗为普通新星，明确了超亮新星的判定依据。
AI中文摘要：
银河系中的两颗极快新星V1500 Cyg和V1674 Her达到了绝对V星等M_{V, max}≈-10.4，这类最亮的新星被定义为超亮新星。当光学厚的激波壳在新星（白矮星）光球层外很远的位置形成，并以每秒数千公里的速度膨胀时，就会产生这种超亮现象。我们通过将6颗候选新星CP Lac、CP Pup、V838 Her、V597 Pup、V5583 Sgr和V5589 Sgr的V波段光变曲线，与我们计算的1.25 M☉和1.35 M☉白矮星的新星风自由-自由发射模型光变曲线进行对比分析。采用该方法分析数据后，我们得到V838 Her的M_{V, max}=-10，其峰值光学光度较大的原因是抛出了光学厚壳，这与我们之前针对V1674 Her的结论一致。其余5颗新星CP Lac、CP Pup、V597 Pup、V5583 Sgr和V5589 Sgr的光变曲线仅能通过不含光学厚激波壳的自由-自由发射模型V波段光变曲线拟合，它们的M_{V, max}均暗于-10星等。我们得出结论，这5颗新星不属于超亮新星。
英文摘要：
The two very fast novae in our Galaxy, V1500 Cyg and V1674 Her, reached the absolute $V$ magnitude of $M_{V,\rm max}\approx -10.4$. These brightest novae are identified as superbright novae. Such superbrightnesses are realized if an optically thick shocked shell forms far outside the nova (white dwarf) photosphere and expands at the velocity of a few thousands km s$^{-1}$. We have analyzed $V$ light curves of six candidates novae, CP Lac, CP Pup, V838 Her, V597 Pup, V5583 Sgr, and V5589 Sgr by comparing with our model nova light curves of 1.25 $M_\odot$ and 1.35 $M_\odot$ white dwarfs calculated with the free-free emission from a nova wind. Analyzing the data with our method, we obtain $M_{V, \rm max}=-10$ for V838 Her, and we suggest that its large peak optical luminosity is due to the ejection of an optically thick shell like we suggested for the case of V1674 Her. The light curves of the other five novae, CP Lac, CP Pup, V597 Pup, V5583 Sgr, and V5589 Sgr are reproduced only with the free-free emission model $V$ light curves without an optically thick shocked shell. Their $M_{V,\rm max}$ are fainter than $-10$ mag. We conclude that these five are not superbright novae.
