香港天文論壇

AAVSO Alert Notice 640 Immediate Montitoring of VW Hyi Requested July 5th, 2018: Dr. Christian Knigge has requested immediate monitoring of the SU Uma-type dwarf Novae VW Hyi in order to promptly identify the next outburst. This outburst will trigger radio wavelength observations. As this object has...

AAVSO Alert Notice 639 CH Cyg coverage requested July 3, 2018: The symbiotic variable CH Cyg is undergoing a fade that began on June 25. Multicolor photometry is requested; V and particularly B should take priority over Rc and Ic. Observations made two to three times a week are sufficient; time seri...

AAVSO Alert Notice 638 Nova in Scutum - N Sct 2018 = TCP J18292290-1430460 July 2, 2018 Event: Nova in Scutum - N Sct 2018 = TCP J18292290-1430460 Discovered by: Yukio Sakurai (Mito, Japan) Discovery magnitude: unfiltered CCD magnitude 10.3, on two frames using Nikon D7100 digital camera + 180-mm f/...

more images

2018 June 28 Sun - AR12715 AR12715 is right on the W limb. There is no visible sunspots. One or two small flares appear among the filaments and plages. As the slow motion is still unavailable, I have to continue with push or pull the telescope to put the image in field. This task becomes very tediou...

more images

2018 June 26 Sun - huge filament-plage structure A huge filament together with extensive plage appeared near the E limb on June 21. The filament has intensified over the last few days. It seems this filament originates amid the plages. As the slow motion is still unavailable, I have to continue with...

more images

more images

2018 June 26 Sun - AR12715 AR12715 is now near the W limb. 3 major sunspots, and a few smaller ones, are visible. Flares are visible to the north of the following sunspot, and to the south of the leading 2. Extensive filaments are on display. As the slow motion is still unavailable, I have to contin...

2018 June 24 Sun AR12716 is on the W limb with 2 or 3 barely visible sunspot among bright faculae. Jets from AR12713 appear and go off-disc. AR12715 roughly midway between disc centre and W limb, with several well deveoped susnpots. Flare activity has somewhat subsided. A large patch of filament and...

more images

2018 June 20 Sun - AR12713 AR12713 has undergone major changes since i last observed on June 16. It has shown more flare activities, mainly from the leading pack of sunspots. As the slow motion is still unavailable, I have to continue with push or pull the telescope to put the image in field. This t...

more images

2018 June 20 Sun - AR12714 AR12714 first appeared as a small flare on June 16, and developed into an active region on June 18. The main following sunspot of this AR has a split umbrae, and the leading batch of tiny sunspots are on the lead. Flares mainly originate from this leading sunspots. As the ...