GCN Circulars
GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. See the documentation for help with subscribing to or submitting Circulars.
Search for Circulars by submitter, subject, or body text (e.g. 'Fermi GRB').
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
Advanced Search
To narrow the search results, use advanced search syntax. This allows for specifying which circular field to search (submitter, subject, and/or body). For additional information, refer to the advanced search documentation.
Advanced Search Examples (click to copy):
subject:"Swift"body:"GRB"submitter:"Judith Racusin"3037 results found.
- LIGO/Virgo G194575: CQUEAN/LOAO observations
- LIGO Virgo G194575: MWA Observations
- LIGO/Virgo G194575: more details on transients from Pan-STARRS in the RA=1hr localisation region
- LIGO/Virgo G194575: Mini-MegaTORTORA observations
- GRB 151021A: MITSuME Okayama Ks-band upper-limit
- LIGO/Virgo G184098: TAROT network optical observations
- LIGO/Virgo G184098: iPTF Optical Transient Candidates
- LIGO/Virgo G184098: TAROT La Silla Observatory optical observations (TZAC)
- GRB 150915A: GROND detection of an optical counterpart candidate
- GRB 150907A: Swift-XRT afterglow detection
- GRB 150910A: MITSuME Ishigakijima Optical Observation after 1 day
- GRB 150910A: SAO RAS optical photometry
- Konus-Wind observation of GRB 150906B
- IPN Triangulation of GRB 150906B (short/intense)
- GRB 150907A: Swift-XRT observations
- ANTARES neutrino Alert150901.32 alert and Swift XRT counterpart: MASTER optical observations and new possible candidate
- Konus-Wind observation of GRB 150819B
- IPN Triangulation of GRB 150819B (short / very intense)
- GRB 150818A: Mondy optical observations
- GRB 150725A: MAXI/GSC detection
- Swift IGR J00291+5934: MASTER Optical flare detection
- Trigger 648422: Swift possible detection of a source in NGC4552
- Trigger 645944: Swift detection of H1745-203
- V404 Cyg: MASTER Swift, Integral alert observations
- GRB 150615A: Swift detection of a burst
- GRB150607A: Discovery Channel Telescope Optical Observations
- Konus-Wind observation of GRB 150607A
- Konus-Wind observation of GRB 150530A
- GRB 150530A: Fermi GBM observation
- GRB 150530A: Swift detection of a burst
- Konus-Wind observation of GRB 150523A
- GRB 150518A: MAXI-GSC further analysis
- Konus-Wind observation of GRB 150518A
- GRB 150518A: MAXI/GSC detection
- Swift Trigger 639636: a possible GRB
- GRB 150424A: Swift detection of a short burst
- GRB 150418A: Swift-XRT observations
- GRB 150403A: Swift-BAT refined analysis
- GRB 150403A: Swift/UVOT Detection
- GRB 150323C: Khureltogot optical observations
- GRB 150403A: Enhanced Swift-XRT position
- GRB 150403A: Swift detection of a burst with an optical counterpart
- GRB 150120B: GMG observation
- GRB 150323C: Mondy optical observations
- GRB 150323C: MASTER-net optical observation
- GRB 150318A: Skynet PROMPT-CTIO Observations
- GRB 150317A: Swift detection of a burst
- GRB 150313A: MAXI/GSC detection
- GRB 150305A: Swift XRT confirms weak INTEGRAL event as a new GRB
- GRB 150301C: XRT detection of a potential counterpart of BAT trigger 633105
- GRB 150302A: NOT afterglow candidate
- GRB 150302A: Swift detection of a burst
- GRB 150301A: GROND Observations
- GRB 150301A: Swift detection of a short burst or new SGR
- IPN Triangulation of GRB 150220A
- Trigger 631946: Swift detection of H1745-203
- Trigger 631747: Swift detection of 4U 0614+09
- GRB 150206B: Fermi GBM detection
- Swift Trigger 629693: probably not real
- GRB 150203A: P60 observations
- Swift Trigger 629206 is likely 1RXS J180408.9-342058
- GRB 150120B: Mondy optical observations
- Konus-Wind observation of GRB 150118B
- Trigger 626581: Swift detection of GRO J1008-57
- The Swift Detection of a Large Flare from the RS CVn Binary SZ Psc
- Swift detection of the variable star SZ Psc
- GRB 150110A: MAXI/GSC detection
- GRB 141220A: Swift-XRT refined Analysis
- GRB 141212A: MITSuME Okayama upper limits
- GRB 141207A: Swift-XRT afterglow candidate detection
- IPN Triangulation of GRB 141202A (short/hard)
- GRB 141121A: MITSuME Ishigakijima Optical Observation
- GRB 141121A: LCO-FTN observations
- GRB 141121A: MAXI/GSC detection
- IPN Triangulation of GRB 141118A
- GRB 141015A: TAROT La Silla observatory optical observations
- IPN Triangulation of GRB 141104A (long/very bright)
- GRB 141028A: SAO RAS Zeiss-1000 photometry
- GRB 141029B: Fermi GBM detection
- GRB 141022A: Swift detection of a burst
- Konus-Wind observation of GRB 141017A
- GRB 141017A: Zadko observatory - Gingin optical observations
- IPN Triangulation of GRB 141011A (short/hard)
- GRB 140930B: MASTER early possible OT detection
- GRB 140930B: MASTER early optical observations
- GRB 140930B: Swift detection of a short burst
- Konus-Wind observation of GRB 140928A
- GRB 140916A: Swift detection of a burst
- GRB 140907A : Optical observations from Nanshan
- GRB 140907A: Swift detection of a burst with an optical counterpart
- GRB 140903A: MAXI/GSC upper limit
- IPN Triangulation of GRB 140825A (very intense/long)
- GRB140819A: Deep GROND Upper Limits
- Fermi trigg_num 430148973: OSN I-band observations
- Swift trigger 609139 is probably 4U 1850-03
- GRB 140808A: Swift/UVOT Upper Limits
- Trigger 607399: Swift detection of SGR1806-20
- GRB 140719B, Swift-BAT refined analysis
- Swift detection of UX Ari
- GRB 140706A: Swift detection of a burst with an optical counterpart