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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"

19548 results found.

  1. LIGO/Virgo G298936 : Fermi-LAT search for a high-energy gamma-ray counterpart
  2. LIGO/Virgo G298936: Swift/BAT data search
  3. LIGO/Virgo G298048: Continued VLA monitoring at 6 GHz
  4. LIGO/Virgo G298936 ANTARES search
  5. LIGO/Virgo G298936: IceCube neutrino observations
  6. GRB 170822A: RATIR Optical and NIR Observations
  7. GRB 170822A: AbAO optical upper limit
  8. GRB 170822A: Swift/UVOT Upper Limits
  9. LIGO/Virgo G298048: Chandra X-ray observations
  10. GRB 170822A: Enhanced Swift-XRT position
  11. LIGO/Virgo G298048: CALET Observations
  12. GRB 170822A: Swift detection of a burst
  13. LIGO/Virgo G298048: MWA Observations of Error Region
  14. LIGO/Virgo G298048: VLA observation at 15 GHz
  15. LIGO/Virgo G298048 ANTARES search (2)
  16. LIGO/Virgo G298048: Kanata/HONIR NIR photometry of the possible counterpart of G298048
  17. LIGO/Virgo G298389: Swift/BAT data search
  18. LIGO/Virgo G298048: optical observations of CHILESCOPE observatory
  19. LIGO/Virgo G298048: Pan-STARRS izy photometry monitoring of SSS17a/DLT17ck
  20. LIGO/Virgo G298389 : Fermi-LAT search for a high-energy gamma-ray counterpart
  21. LIGO/Virgo G298048: VLA observation at 6 GHz
  22. LIGO/Virgo G298048: Continued VLA observations
  23. LIGO/Virgo G298389: INTEGRAL search for a prompt gamma-ray counterpart
  24. LIGO/Virgo G298048: Etelman Observatory observation of the potential LIGO EM counterpart SSS17a
  25. LIGO/Virgo G298048: GROND observations of candidate optical counterpart
  26. LIGO/Virgo G298389 ANTARES search
  27. LIGO/Virgo G298048: GROND photometry of candidate optical counterpart reveals brightening in the NIR
  28. LIGO/Virgo G298048: Additional Swope Observations of SSS17a
  29. LIGO/Virgo G298048: prior photometry from VISTA Hemisphere Survey
  30. LIGO/Virgo G298048: Archival 2MASS and Spitzer non-detections of the potential LIGO EM counterpart SSS17a
  31. LIGO/Virgo G298048: Archival VLA observations
  32. LIGO/Virgo G298048: AGILE-GRID analysis of the potential counterpart field
  33. LIGO/Virgo G298048: ASKAP search for fast radio bursts
  34. LIGO/Virgo G298048: TZAC TAROT Reunion (TRE) observations
  35. LIGO/Virgo G298048: Likelihood of SSS17a Being an Unrelated Extragalactic Transient in NGC 4993
  36. LIGO/Virgo G298048: REM optical/NIR observations
  37. LIGO/Virgo G298048, Fermi GBM trigger 524666471/170817.529: MAXI/GSC observations
  38. LIGO/Virgo G298048: Gemini-South Near-Infrared Photometry of the Optical Transient Candidate
  39. LIGO/Virgo G298048: VISTA/VIRCAM detection of candidate counterpart
  40. LIGO/Virgo G298048: Optical Candidate Shows No Evidence for Previous Activity in Archival SkyMapper Transient Survey Data
  41. LIGO/Virgo G298048: Las Cumbres Observatory Detection of The Possible Optical Counterpart in NGC 4993
  42. LIGO/Virgo G298048 : Fermi-LAT search for a high-energy gamma-ray counterpart
  43. LIGO/Virgo G298048 - Update on Fermi/GBM GRB 170817A Analysis
  44. LIGO/Virgo G298048: AGILE GRID observations
  45. LIGO/Virgo G298048: AGILE MCAL observations
  46. LIGO/Virgo G298048: Swift/BAT data search
  47. LIGO/Virgo G297595: Pierre Auger Observatory neutrino follow-up
  48. LIGO/Virgo G298048 ANTARES search
  49. GRB 170817A: Fermi GBM detection
  50. IPN Triangulation of GRB 170816A (short/hard)
  51. LIGO/Virgo G298048: Potential host galaxies from the GLADE catalog
  52. LIGO/Virgo G298048: Further analysis of a binary neutron star candidate with updated sky localization
  53. LIGO/Virgo G296853 TZAC TAROT observations
  54. LIGO/Virgo G297595: Subaru Hyper Suprime-Cam follow-up observations
  55. LIGO/Virgo G296853: Pierre Auger Observatory neutrino follow-up
  56. LIGO/Virgo G297595: Fermi GBM Observations
  57. LIGO/Virgo G297595: Swift/BAT data search
  58. LIGO/Virgo G297595 : Fermi-LAT search for high-energy gamma-ray counterpart
  59. GRB 170813A: Swift/UVOT Upper Limits
  60. LIGO/Virgo G297595 ANTARES search
  61. LIGO/Virgo G297595: INTEGRAL search for a prompt gamma-ray counterpart
  62. LIGO/Virgo G297595: IceCube neutrino observations
  63. GRB 170813A: RATIR Optical and NIR Observations
  64. GRB 170810A: AbAO optical upper limit
  65. GRB 170813A: Enhanced Swift-XRT position
  66. GRB 170813A: Swift detection of a burst
  67. LIGO/Virgo G296853: BOOTES-1 and GTC optical observations
  68. GRB 170810A: Swift/UVOT Detection
  69. GRB 170810A: Enhanced Swift-XRT position
  70. GRB 170810A: Swift detection of a burst with a bright optical counterpart
  71. LIGO/Virgo G296853: HAWC follow-up
  72. LIGO/Virgo G296853: Super-AGILE observations
  73. LIGO/Virgo G296853: no INTEGRAL data at the time of the event
  74. LIGO/Virgo G296853: Fermi-LAT search for high-energy gamma-ray counterpart
  75. LIGO/Virgo G296853: Fermi GBM Observations
  76. LIGO/Virgo G296853: Swift/BAT data search
  77. LIGO/Virgo G296853 ANTARES search
  78. GRB 170808B: Fermi GBM observation
  79. IPN Triangulation of GRB 170805A (short)
  80. GRB 170714A: ATCA detection of the radio counterpart
  81. GRB 170808A: MAXI/GSC detection
  82. GRB 170728B: TShAO, SAO RAS and AbAO optical observations
  83. GRB 170804A: LCO Observations
  84. GRB 170804A: Swift/UVOT Detection
  85. GRB 170804A: Swift-XRT refined Analysis
  86. GRB 170804A: Enhanced Swift-XRT position
  87. GRB 170803A: Swift/UVOT Detection
  88. GRB 170804A: Swift detection of a burst with optical counterpart
  89. Swift Trigger 766161 is not a GRB
  90. GRB 170803A: Enhanced Swift-XRT position
  91. GRB 170803A: Swift detection of a burst with an optical counterpart
  92. Swift J181723.1-164300: Swift detection of another pulse of the new Galactic source
  93. GRB 170728B: Swift/UVOT Further Analysis
  94. GRB 170714A: Chandra observations
  95. GRB 170728B: MASTER-IAC first minute short GRB early OT detection
  96. GRB 170728B: COATLI Observations And Confirmation of Fading
  97. GRB 170728B: Swift/UVOT Upper Limits
  98. GRB 170728B iTelescope observation
  99. GRB 170728A: Swift/UVOT Detection
  100. GRB 170728A: LCO observations

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