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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').
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"

3140 results found.

  1. IPN Triangulation of GRB 170207A (long/very bright)
  2. LIGO/Virgo G270580: Las Cumbres Observatory Follow-up Observations
  3. GRB 170126A: AstroSat CZTI detection
  4. GRB 170126A: Swift detection of a burst with an optical counterpart
  5. LIGO/Virgo G270580: Pan-STARRS coverage and 124 optical transients
  6. LIGO/Virgo G270580: Observations of initial skymap by Project Mini-GWAC of SVOM
  7. Trigger 731535: Swift detection of GRS 1716-249/GRO J1719-24/V2293 Oph
  8. LIGO/Virgo G268556: Pan-STARRS1 observations and summary of transient sources
  9. Trigger 731257: Another Swift-BAT detection of GRS 1716-249/GRO J1719-24/V2293 Oph
  10. Trigger 731183: Swift detection of GRS 1716-249/GRO J1719-24/V2293 Oph
  11. LIGO/Virgo G268556/GW170104: Lomonosov BDRG observations
  12. LIGO/Virgo G268556: ATLAS imaging of the skymap
  13. LIGO/Virgo G211117 / GW151226: LOFAR follow-up
  14. GRS 1716-249/GRO J1719-24/V2293 Oph, Swift-BAT refined analysis
  15. GRB161219.78 MASTER-Net OT detection
  16. GRB 161219B: Watcher optical observations
  17. IPN Triangulation of GRB 161218B (long/very bright)
  18. GRB 161219B: GROND afterglow observations
  19. GRB 161207A: POLAR observation
  20. GRB 161117A: MASTER-OAFA (Argentina) prompt OT observations
  21. GRB 161117B: Enhanced Swift-XRT position
  22. GRB 161117B: Swift detection of a burst
  23. GRB 161113A: Swift-XRT refined Analysis
  24. GRB 161105A: MASTER-IAC early optical observations
  25. GRB 161104A: Swift detection of a short burst
  26. GRB 161017A: MITSuME Akeno Optical Observation
  27. GRB 161007A: MASTER-net early optical observations
  28. GRB 160925A: Kottamia R-band observation
  29. GRB 160917A: Swift/UVOT Detection
  30. GRB 160917A: Mondy optical observations
  31. GRB 160912A: Fermi GBM detection
  32. GRB160821A: Astrosat CZTI (veto) detection
  33. GRB 160816A: MASTER inspection
  34. IPN Triangulation of GRB 160806A
  35. FACT follow-up of IceCube20160731
  36. Swift Trigger 704444 is probably not an astrophysical event.
  37. GRB 160623A: optical astrometry, photometry, and redshift
  38. GRB 160709A CALET Gamma-Ray Burst Monitor detection
  39. IPN Triangulation of GRB 160702A (short/hard)
  40. SGR 1935+2154: CALET Gamma-Ray Burst Monitor detections
  41. GRB 160705B: RATIR Optical and NIR Observations and Confirmation of the Fading Afterglow
  42. GRB 160705B: Swift-BAT refined analysis
  43. GRB 160705B: LT optical candidate
  44. GRB 160705B: Swift detection of a burst
  45. GRB 160625B: RTT150 optical observations
  46. GRB 160625B: Fermi-LAT refined analysis
  47. GRB 160623A: RATIR Optical and NIR Observations, Afterglow Confirmation
  48. GRB 160623A: Mondy optical observations
  49. GRB 160623A: Swift-XRT afterglow detection
  50. Konus-Wind observation of GRB 160607A
  51. GRB160601A: Kanata Telescope I- and Ks-bands upper limits
  52. Another Swift detection of SGR 1935+2154 (trigger #687124)
  53. GRB 160501A MASTER-NET early observations
  54. GRB 160501A: Swift detection of a burst
  55. MASTER search for counterpart to the IceCube event 67093193 (run 127853)
  56. LIGO/Virgo G211117: EWE for NOWT of 12 days follow-up of northern sky
  57. GRB 160412A: Swift detection of a burst
  58. GRB 160410A: GROND optical detection
  59. LIGO/Virgo G211117: LOFAR follow-up
  60. GRB 160324A: CALET Gamma-Ray Burst Monitor detection
  61. GRB 160325A, Swift-BAT refined analysis
  62. GRB 160325A: Swift detection of a burst
  63. GRB 160321A: Swift detection of a probable burst
  64. LIGO/Virgo G211117: EWE for NOWT follow-up of northern sky
  65. Swift detection of a likely new SGR: SGR 0755-2933
  66. GRB 160314A: VLT/X-shooter redshift
  67. Swift trigger 677890 is noise
  68. GRB 160303A, Swift-BAT refined analysis
  69. GRB 160303A: VLT/FORS2 afterglow obervations
  70. GRB 160303A: Swift detection of a burst, possibly short
  71. GRB 160225.81/FERMI Trigg 478121069: MASTER OT J095503.19-355149.4 detection
  72. GRB 160221A: A long GRB detected by INTEGRAL
  73. GRB 160219A: Fermi GBM detection
  74. LIGO/Virgo G211117: LOFAR follow-up
  75. GRB 160131A: Mondy optcial observations
  76. GRB 160127A: TAROT La Silla observatory optical light curve
  77. LIGO/Virgo G211117: Preliminary VLA observation summary of PS15dpn
  78. LIGO/Virgo G211117: Further Swift-XRT sources
  79. LIGO/Virgo G211117: Subaru Hyper Suprime-Cam follow-up observation
  80. GRB 160107A: MAXI/GSC detection
  81. GRB 160104A: MITSuME Okayama upper limits
  82. LIGO/Virgo G211117: Summary of Pan-STARRS transients
  83. LIGO/Virgo G211117: LOFAR follow-up
  84. GRB 160101A: MAXI/GSC detection
  85. LIGO/Virgo G211117: 44 transients from Pan-STARRS data during 2015-12-28/30
  86. LIGO/Virgo G211117: MAGIC very-high energy gamma-ray observations
  87. LIGO/Virgo G211117: Optical Observations with Kiso Schmidt telescope and KWFC
  88. LIGO/Virgo G211117: iPTF Optical Transient Candidates
  89. GRB 151229A: Swift detection of a short burst
  90. LIGO/Virgo G211117: Optical NIR observation with Kanata telescope
  91. LIGO/Virgo G211117: Optical follow-up with Kanata telescope
  92. GRB 151222A: Fermi GBM detection
  93. GRB 151210B: Fermi GBM observation
  94. GRB151215A: Early optical light curve from pt5m, La Palma
  95. GRB 151205C: Optical follow-up observations at Kiso
  96. GRB 151205C: MAXI/GSC detection
  97. GRB 151118A: Early optical limit from pt5m, La Palma
  98. GRB 151027A: SAO RAS and Mt. Terskol observations
  99. GRB GRB 151118A: MASTER-NET optical observations
  100. GRB 151107B: MASTER-NET OT detection inside the FERMI error box

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