论文标题
活跃小行星（6478）Gault的旋转和颜色特性
Spinning and color properties of the active asteroid (6478) Gault
论文作者
论文摘要
我们报告了（6478）Gault的准确$ bvr_ {C} $观察，这是凤凰家族中直径为5-6公里的内部主皮带小行星，以其零星的类似彗星的尘埃折射而闻名。尽管不能完全排除这种奇怪的行为，但这种奇怪的行为主要被解释为Yorp旋转后的重新配置。我们沿2019年4月期间收集了光学观测，轨道相角在$ 12^{\ circ} -21^{\ circ} $之间，以搜索小行星快速旋转旋转的直接证据。我们和其他光度观察结果支持了$ 3.34 \ pm 0.02 $小时的普遍价值。在YORP旋转假设中，这段时间指向散装密度$ρ\约1 $ $ \ textrm {g}/\ textrm {cm}^3 $。平均颜色为$ b-v = +0.82 _ {\ pm 0.3} $，$ v-r_ {c} = +0.28 _ {\ pm 0.06} $和$ b-r_ {c} = +1.11 _ {\ pm pm 0.4} $，但我们已经在4月的comply of us n. 3. 0.09 $ 〜MAG。这种颜色的变化可能是由于小行星旋转并支持了以下假设：正如Marsset等人在2019年3月31日和4月8日在2019年3月31日和4月8日进行的光谱观察表所表明的那样。 （2019）。
We report on accurate $BVR_{c}$ observations of (6478) Gault, a 5-6 km diameter inner main-belt asteroid in the Phocaea family, notable for its sporadic, comet-like ejection of dust. This curious behavior has been mainly interpreted as reconfigurations after YORP spin-up, although merging of a contact binary system cannot be fully excluded. We collected optical observations along the 2019 March-April period, at orbital phase angles between $12^{\circ}-21^{\circ}$, to search for direct evidence of asteroid quick spinning rotation. A prevailing period value of $3.34 \pm 0.02$ hours is supported by our and other photometric observations. In the YORP spin-up hypothesis, this period points to a bulk density $ρ\approx 1$ $\textrm{g}/\textrm{cm}^3$. The mean colors are $B-V = +0.82_{\pm 0.3}$, $V-R_{c} = +0.28_{\pm 0.06}$ and $B-R_{c} = +1.11_{\pm 0.4}$, but we have observed a strong bluer color during the April session, with about $Δ(B-V) \sim 0.35 \pm 0.09$~mag. This color change can be due to asteroid rotation and support the hypothesis that there is a bluer surface under the Gault's dust, as indicated by spectroscopic observations made on 2019 March 31 and April 8 by Marsset et al. (2019).
