This NASA/ESA Hubble Space Telescope Picture of the Week features a sparkling spiral galaxy paired with a prominent star, both in the constellation Virgo. While the galaxy and the star appear to be close to one another, even overlapping, they’re actually a great distance apart.
ESA/Hubble & NASA, S. J. Smartt, C. Kilpatrick
This NASA/ESA Hubble Space Telescope image features a sparkling spiral galaxy paired with a prominent star, both in the constellation Virgo. While the galaxy and the star appear to be close to one another, even overlapping, they’re actually a great distance apart. The star, marked with four long diffraction spikes, is in our own galaxy. It’s just 7,109 light-years away from Earth. The galaxy, named NGC 4900, lies about 45 million light-years from Earth.
This image combines data from two of Hubble’s instruments: the Advanced Camera for Surveys, installed in 2002 and still in operation today, and the older Wide Field and Planetary Camera 2, which was in use from 1993 to 2009. The data used here were taken more than 20 years apart for two different observing programs — a real testament to Hubble’s long scientific lifetime!
Both programs aimed to understand the demise of massive stars. In one, researchers studied the sites of past supernovae, aiming to estimate the masses of the stars that exploded and investigate how supernovae interact with their surroundings. They selected NGC 4900 for the study because it hosted a supernova named SN 1999br.
In the other program, researchers laid the groundwork for studying future supernovae by collecting images of more than 150 nearby galaxies. When researchers detect a supernova in one of these galaxies, they can refer to these images, examining the star at the location of the supernova. Identifying a supernova progenitor star in pre-explosion images gives valuable information about how, when, and why supernovae occur.
Image credit: ESA/Hubble & NASA, S. J. Smartt, C. Kilpatrick
这张由NASA/ESA哈勃太空望远镜拍摄的本周图片呈现了一幅令人惊艳的景象：一座闪耀的螺旋星系与一颗明亮的恒星同框，位于室女座中。虽然星系与恒星在图像中看起来彼此靠近、甚至似乎重叠，但实际上它们相距遥远。
影像来源: ESA/Hubble & NASA, S. J. Smartt, C. Kilpatrick
这张由NASA/ESA哈勃太空望远镜拍摄的本周图片呈现了一幅令人惊艳的景象：一座闪耀的螺旋星系与一颗明亮的恒星同框，位于室女座中。虽然星系与恒星在图像中看起来彼此靠近、甚至似乎重叠，但实际上它们相距遥远。这张图像中的恒星带有四条明显的衍射尖刺，位于我们银河系内，距离地球仅有7,109光年；而图像中闪烁的螺旋星系名为NGC 4900，则位于约4,500万光年之外。
这幅图像结合了哈勃望远镜的两台仪器的数据：2002年安装、至今仍在运行的先进巡天相机（ACS），以及1993年至2009年服役的第二代广域和行星照相机（WFPC2）。这些数据采集时间相隔20多年，分别用于两个不同的观测项目，这也体现了哈勃望远镜长期稳定的科研能力。
两个项目都旨在研究大质量恒星的终结过程。其中一个项目专注于历史超新星爆发位置的研究，旨在估算爆炸恒星的质量，并探究超新星如何与其周围环境相互作用。他们选择NGC 4900进行研究，因为它拥有一颗名为SN 1999br的超新星。
另一个项目则为未来的超新星研究奠定基础：通过拍摄150多个邻近星系的图像，建立观测档案。这样一来，当某个星系中探测到新的超新星爆发时，研究人员可以回顾这些早期图像，分析爆发位置上曾经存在的恒星。如果能在爆炸前的图像中识别出超新星的母星，将有助于深入了解超新星是如何、何时以及为何发生的。
影像来源: ESA/Hubble & NASA, S. J. Smartt, C. Kilpatrick
