NGC 4051 is an intermediate spiral galaxy in the constellation of Ursa Major. [2] It was discovered on 6 February 1788 by John Herschel. [5] NGC 4051 contains a supermassive black hole with a mass of 1.73 million M ☉. [6] This galaxy was studied by the Multicolor Active Galactic Nuclei Monitoring 2m telescope. [7]

NGC 4051是一个位于大熊座的中間螺旋星系，1788年2月6日由約翰·赫歇爾发现 [2] [5] 。星系中心的超大質量黑洞质量为173万M ☉ [6] 。人们在星系内观测到超新星SN 1983I、SN 2010br和N 2003ie [4] 。

NGC 4051 是一個位於 大熊座 的 中間螺旋星系，1788年2月6日由 約翰·赫歇爾 發現 [2][5]。 星系中心的 超大質量黑洞 質量為173萬 M☉[6]。 人們在星系內觀測到 超新星 SN 1983I、SN 2010br和N 2003ie [4]。 NGC 4051是 西佛星系，屬於 大熊座星系團 [7][8][9][10]， 本動速度 …

2004年1月1日 · We report on the results of a three-year program of coordinated X-ray and optical monitoring of the narrow-line Seyfert 1 galaxy NGC 4051. The principal results of this program are: (1) The H-beta emission line time lag and Doppler width yield a virial mass estimate of about 1.1 mission solar masses, at the extreme low end of AGN masses.

2019年6月14日 · These exploding stars glow so incredibly brightly when they first form that they can be spotted from afar using telescopes such as the NASA/ESA Hubble Space Telescope. The subject of this image, a spiral galaxy named NGC 4051 — about 45 million light-years from Earth — has hosted multiple supernovae in past years.

2025年1月22日 · NICER observations of an Active Galactic Nucleus (AGN), NGC 4051, have charted the geometry of the emission region of the central supermassive black hole. Our investigation of X-ray variability in NGC 4051 has detected extreme variations spanning a factor of 40 to 50 over a mere 10 to 12 hours.

2004年5月1日 · Archival XMM–Newton data on the nearby Seyfert galaxy NGC 4051, taken in relatively high‐ and low‐flux states, offer a unique opportunity to explore the complexity of its X‐ray spectrum. We find the hard X‐ray band to be significantly affected by reflection from cold matter, which can also explain a non‐varying, narrow Fe K fluorescent line.

2000年9月1日 · We report on a three-year program of coordinated X-ray and optical monitoring of the narrow-line Seyfert 1 galaxy NGC 4051. The rapid continuum variations observed in the X-ray fluxes are not detected in the optical, although the X-ray and optical continuum fluxes are correlated on time scales of many weeks and longer.

2000年5月22日 · We report on the results of a three-year program of coordinated X-ray and optical monitoring of the narrow-line Seyfert 1 galaxy NGC 4051. The rapid continuum variations observed in the X-ray spectra are not detected in the optical, although the time-averaged X-ray and optical continuum fluxes are well-correlated.

We present a comprehensive examination of the X-ray variability of the narrow-line Seyfert 1 (NLS1) galaxy NGC 4051, one of the most variable active galactic nuclei (AGN) in the sky.