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GCN Circulars

GCN Circulars are rapid bulletins submitted by and distributed to the community. 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"

3768 results found.

  1. LIGO/Virgo G298048: Archival 2MASS and Spitzer non-detections of the potential LIGO EM counterpart SSS17a
  2. LIGO/Virgo G298048: SkyMapper uvgri photometry of the candidate in NGC 4933
  3. LIGO/Virgo G298048: TZAC TAROT Reunion (TRE) observations
  4. LIGO/Virgo G298048: Subaru HSC follow-up observations
  5. LIGO/Virgo G298048: Inspection of archival HST data at the position of the potential optical counterpart
  6. LIGO/Virgo G298048: REM optical/NIR observations of candidate in NGC 4993
  7. LIGO/Virgo G297595: Subaru Hyper Suprime-Cam follow-up observations
  8. LIGO/Virgo G296853: Pierre Auger Observatory neutrino follow-up
  9. LIGO/Virgo G297595: Fermi GBM Observations
  10. GRB 170813A: Swift detection of a burst
  11. LIGO/Virgo G296853: BOOTES-1 and GTC optical observations
  12. LIGO/Virgo G296853: Insight-HXMT observations
  13. LIGO/Virgo G296853 : MAXI/GSC observations
  14. LIGO/Virgo G296853: Super-AGILE observations
  15. LIGO/Virgo G296853: no INTEGRAL data at the time of the event
  16. LIGO/Virgo G296853: Fermi-LAT search for high-energy gamma-ray counterpart
  17. LIGO/Virgo G296853: AGILE GRID observations
  18. LIGO/Virgo G296853: Swift/BAT data search
  19. LIGO/Virgo G296853: AGILE MCAL observations
  20. LIGO/Virgo G296853: Identification of a GW Binary Merger Candidate
  21. GRB 170808A: MAXI/GSC detection
  22. GRB 170728B: time correction to MASTER GCN Circular 21391
  23. Swift J181723.1-164300: Swift detection of another pulse of the new Galactic source
  24. GRB 170728B: BOOTES-2/TELMA optical detection during the extended gamma-ray phase
  25. GRB 170728B: MASTER-IAC first minute short GRB early OT detection
  26. GRB 170728B iTelescope observation
  27. GRB 170728B: Fermi GBM detection
  28. GRB 170728B: Fermi-LAT detection
  29. GRB 170728B: LT afterglow confirmation
  30. GRB 170728B: TNG optical afterglow candidate
  31. Swift triggers on a new galactic source: Swift J181723.1-164300
  32. GRB 170728A: Swift detection of a burst
  33. Fermi GBM Detection of possible burst from AXP 4U 0142+61
  34. GRB 170705A: TShAO optical observations
  35. GRB 170710B: Fermi GBM observation
  36. GRB 170629A: Fermi GBM observation
  37. GRB 170626A: MASTER-Tunka OT detection.
  38. GRB 170626A: Swift-BAT refined analysis
  39. GRB 170626A: TNG optical observations
  40. GRB 170626A: Afterglow detection from 1.5m OSN
  41. GRB 170626A: SAO RAS possible OT detection
  42. GRB 170626A: Swift-XRT refined Analysis
  43. GRB 170626A: Swift detection of a burst
  44. IPN Triangulation of GRB 170616A (short/hard)
  45. GRB 170519A: Mondy optical observations
  46. Swift Trigger 755873: MASTER Net optical observations
  47. GRB 170519A: CrAO optical observations
  48. LIGO/Virgo G268556: optical observations and classification of Pan-STARRS1 transients
  49. LIGO/Virgo G268556: BSA radio observations at 110 MHz
  50. GRB 170511A CALET Gamma-Ray Burst Monitor detection
  51. GRB 170522A: Swift-XRT observations
  52. LIGO/Virgo G277583: UH88/SNIFS classification of ATLAS and PS1 transients
  53. GRB 170516A: Swift-BAT refined analysis
  54. LIGO/Virgo G284239: Konus-Wind observations
  55. LIGO/Virgo G284239: H.E.S.S. very-high energy gamma-ray follow-up
  56. LIGO/Virgo G284239: HAWC follow-up
  57. GRB 170428A CALET Gamma-Ray Burst Monitor detection
  58. Short GRB 170428A: MASTER-OAFA final reduction of the optical observations
  59. GRB 170428A: GROND detection of the afterglow
  60. GRB 170428A: Xinglong 2.16-m upper limit and host galaxy candidate
  61. GRB 170428A: MASTER-OAFA early optical observations
  62. GRB 170419A: Swift detection of a burst
  63. Swift Trigger 748858: a possible GRB
  64. Fermi trigger 512347439/GRB 170327A: MASTER-SAAO possible OT detection
  65. LIGO/Virgo G277583: CALET Observations
  66. GRB 170318A: Prompt enhanced Swift-XRT position
  67. IceCube-170312A: MASTER follow-up observations
  68. GRB 170317A: MITSuME Okayama Optical Observation
  69. LIGO/Virgo G277583: ATLAS coverage and transients over the first 2 days
  70. LIGO/Virgo G277583: ERRATUM LV GCN 20871: TAROT Calern (TCA) observations
  71. LIGO/Virgo G277583: TAROT Calern (TCA) observations
  72. LIGO/Virgo G277583: SVOM/Mini-GWAC observations of the initial skymap
  73. LIGO/Virgo G275404: Medicina radio follow-up of near-infrared
  74. Konus-Wind observation of GRB 170311B
  75. LIGO/Virgo G270580: optical observations and classification of PS and MASTER sources
  76. LIGO/Virgo G275697: Further Swift-XRT sources
  77. GRB 170228B CALET Gamma-Ray Burst Monitor detection
  78. LIGO/Virgo G275697: Additional iPTF Optical Transient Candidates
  79. GRB 170228B: POLAR Observation
  80. GRB 170228A: Fermi GBM observation
  81. GRB 170228A: Fermi-LAT detection
  82. LIGO/Virgo G275697: CALET Observations
  83. LIGO/Virgo G275697: MASTER automatic follow up detection
  84. LIGO/Virgo G275697: CNEOST optical observations
  85. LIGO/Virgo G275697: REM optical/NIR observations
  86. LIGO/Virgo G275404: SVOM/Mini-GWAC: Observations of initial skymap
  87. LIGO/Virgo G274296: GRAWITA-Campo Imperatore observation
  88. GRB 170222A: Swift-XRT observations
  89. IPN Triangulation of GRB 170222A (short/hard)
  90. LIGO/Virgo G274296: J-GEM optical/NIR follow-up observations
  91. LIGO/Virgo G274296: Asiago 1.82m Optical Observations
  92. LIGO/Virgo G274296: PESSTO classification of 9 Pan-STARRS transients
  93. IPN Triangulation of GRB 170219A (short/hard)
  94. LIGO/Virgo G274296: Pan-STARRS imaging and discovery of 70 transients
  95. Konus-Wind observation of GRB 170209A
  96. Correction to GCN 20640: GRB 170208B: GROND observations
  97. GRB 170208B WHT nIR candidate afterglow
  98. GRB 170208B: GROND observations
  99. LIGO/Virgo G270580: Gemini-South Spectroscopic Classification of Optical Transients
  100. GRB 170205A: Swift/UVOT Detection of a Fading Afterglow

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