Scientists have discovered a star behaving like no other seen before, giving fresh clues about the origin of a new class of mysterious objects.
X-ray: NASA/CXC/ICRAR, Curtin Univ./Z. Wang et al.; Infrared: NASA/JPL/CalTech/IPAC; Radio: SARAO/MeerKAT; Image processing: NASA/CXC/SAO/N. Wolk
An unusual star (circled in white at right) behaving like no other seen before and its surroundings are featured in this composite image released on May 28, 2025. A team of astronomers combined data from NASA’s Chandra X-ray Observatory and the Square Kilometer Array Pathfinder (ASKAP) radio telescope on Wajarri Country in Australia to study the discovered object, known as ASKAP J1832−0911 (ASKAP J1832 for short).
ASKAP J1832 belongs to a class of objects called “long period radio transients” discovered in 2022 that vary in radio wave intensity in a regular way over tens of minutes. This is thousands of times longer than the length of the repeated variations seen in pulsars, which are rapidly spinning neutron stars that have repeated variations multiple times a second. ASKAP J1832 cycles in radio wave intensity every 44 minutes, placing it into this category of long period radio transients. Using Chandra, the team discovered that ASKAP J1832 is also regularly varying in X-rays every 44 minutes. This is the first time that such an X-ray signal has been found in a long period radio transient.
Image credit: X-ray: NASA/CXC/ICRAR, Curtin Univ./Z. Wang et al.; Infrared: NASA/JPL/CalTech/IPAC; Radio: SARAO/MeerKAT; Image processing: NASA/CXC/SAO/N. Wolk
科学家近日发现一颗前所未见的异常恒星，其独特行为为一类神秘天体的起源提供了新的线索。
X射线: NASA/CXC/ICRAR, Curtin Univ./Z. Wang et al.; 红外光：NASA/JPL/CalTech/IPAC; 射电: SARAO/MeerKAT; 图像处理: NASA/CXC/SAO/N. Wolk
这张合成图像于2025年5月28日发布，展示了一颗表现极为异常的恒星（右侧白圈内）及其周围环境。一个由天文学家组成的研究团队，结合了美国国家航空航天局（NASA）钱德拉X射线天文台（Chandra X-ray Observatory）和位于澳大利亚瓦贾里原住民土地上的平方公里阵列探路者望远镜（ASKAP）的数据，对该天体进行了深入研究。该天体被命名为ASKAP J1832−0911，简称ASKAP J1832。
ASKAP J1832属于“长周期射电瞬变体”（long period radio transients）类别，这一类天体在2022年首次被发现，特点是在数十分钟内以规律方式变化其射电波强度。这种变化周期比普通脉冲星长成千上万倍。脉冲星是高速旋转的中子星，其辐射变化频率可达到每秒数次。而ASKAP J1832的射电波强度每44分钟周期性变化，因而归入长周期射电瞬变体。
通过钱德拉望远镜，研究团队首次发现ASKAP J1832在X射线波段也以44分钟为周期进行规律性变化。这是科学界首次在长周期射电瞬变体中发现X射线信号的周期性变化。
图像来源: X射线: NASA/CXC/ICRAR, Curtin Univ./Z. Wang et al.; 红外光：NASA/JPL/CalTech/IPAC; 射电: SARAO/MeerKAT; 图像处理: NASA/CXC/SAO/N. Wolk
