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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"

19093 results found.

  1. GRB 170626A: SAO RAS possible OT detection
  2. GRB 170626A: Swift detection of a burst
  3. LIGO/Virgo G288732: Fermi GBM Upper Limits for the LIGO Trigger and LAT Candidate
  4. LIGO/Virgo G288732: Pan-STARRS coverage of the Fermi/LAT candidate position
  5. Swift trigger 758168 is probably not an astrophysical source
  6. Swift Trigger 758005 is Probably Not an Astrophysical Source
  7. GRB 170607A CALET Gamma-Ray Burst Monitor detection
  8. GRB 170606A CALET Gamma-Ray Burst Monitor detection
  9. Swift Trigger 756953 is probably not an astrophysical source
  10. LIGO/Virgo G288732: Kiso/KWFC optical imaging of the possible Fermi/LAT counterpart
  11. LIGO/Virgo G288732: HAWC follow-up
  12. LIGO/Virgo G288732: UKIRT near-IR imaging of the Fermi/LAT candidate
  13. LIGO/Virgo G288732: LBT optical imaging of the Fermi/LAT candidate
  14. LIGO/Virgo G288732 : MAXI/GSC observations
  15. GRB 170607A: Redshift from GTC/OSIRIS
  16. GRB 170607A: ISON/Terskol optical observations
  17. LIGO/Virgo G288732: GWFUNC/NOWT observations of the skymap and follow-up of the Fermi/LAT candidate
  18. LIGO/Virgo G288732: Swift/BAT data search
  19. LIGO/Virgo G288732: Swift-XRT follow up of the putative LAT counterpart
  20. LIGO/Virgo G288732: INTEGRAL search for a prompt gamma-ray counterpart
  21. LIGO/Virgo G288732:SVOM/Mini-GWAC observations of the initial skymap
  22. LIGO/Virgo G288732: Fermi-LAT detection of a weak candidate
  23. GRB 170607A: Correction on the possible host galaxy identification
  24. LIGO/Virgo G288732 ANTARES search
  25. LIGO/VIRGO G288732: Fermi GBM Observations
  26. GRB 170607A: Swift/UVOT Detection
  27. GRB 170607A: MASTER-Tavrida early OT observations
  28. GRB 170607A: NOT optical afterglow detection
  29. GRB 170607A: Swift-XRT refined Analysis
  30. GRB 170607A: Enhanced Swift-XRT position
  31. GRB 170607A: Swift detection of a burst with a bright optical counterpart
  32. GRB 170531B: Zeiss-1000/CrAO optical observations
  33. GRB 170519A: TShAO and AbAO optical observations
  34. GRB 170604A: Swift/UVOT Observations
  35. GRB 170519A: Mondy optical observations
  36. GRB 170604A: RATIR Optical and NIR Observations
  37. GRB 170604A: AbAO optical observations
  38. GRB 170522A: confirmation of the X-ray afterglow
  39. GROND observations of GRB170604A
  40. GRB 170604A: Swift-XRT refined Analysis
  41. GRB 170604A: GTC spectroscopic redshift
  42. GRB 170604A: Enhanced Swift-XRT position
  43. GRB 170604A: Swift-BAT refined analysis
  44. Swift Trigger 755873: a possible GRB
  45. GRB 170604A: optical observations
  46. GRB 170604A: Swift detection of a burst
  47. GRB 170531B: ISON/Terskol optical observations
  48. GRB 170531B: Swift/UVOT Detection
  49. GRB 170531B: SMARTS optical/IR observations
  50. GRB 170531A: Swift/UVOT Upper Limits
  51. GRB 170531B: LCO observations
  52. GRB 170531A: Swift-XRT refined Analysis
  53. GROND observations of GRB 170531B
  54. GRB 170531B: Redshift from GTC/OSIRIS
  55. GRB 170531B: Enhanced Swift-XRT position
  56. GRB 170531B: CrAO confirmation of the afterglow
  57. GRB 170531A: Swift/UVOT Observations
  58. GRB 170531B: Swift detection of a burst
  59. GRB 170531A: Swift detection of a burst
  60. GRB 170519A: CrAO optical observations
  61. GRB 170524B: Swift-UVOT/XRT Confirmation of Afterglow
  62. IPN Triangulation of GRB 170529A (long)
  63. GRB 170519A: ISON/Multa optical observations
  64. LIGO/Virgo G268556: optical observations and classification of Pan-STARRS1 transients
  65. GRB 170526A: Swift/UVOT Upper Limits
  66. LIGO/Virgo G268556: VERITAS Very-High-Energy Gamma-Ray Observations
  67. GRB 170524A: RATIR Optical and NIR Observations
  68. GRB 170526A: Enhanced Swift-XRT position
  69. GRB 170526A: Swift detection of a burst
  70. GRB 170524B: MASTER-OAFA observations
  71. GRB 170524A: TSHAO and CrAO optical observations
  72. GRB 170524B: Swift ToO observations
  73. GRB 170524A: Swift-BAT refined analysis
  74. GRB 170524A: Swift/UVOT Upper Limits
  75. IPN Triangulation of GRB 170522A
  76. GRB 170524A: Enhanced Swift-XRT position
  77. GRB 170524A: Swift detection of a burst (or possible new SGR)
  78. GRB 170522A: LCO McDonald observations
  79. GRB 170522A: Global MASTER-Net job
  80. GRB 170522A: Tiled Swift observations
  81. GRB 170522A: Fermi-LAT detection
  82. GRB 170522A: Fermi GBM detection
  83. GRB 170519A: Watcher optical observations
  84. GRB 170519A: Continued RATIR Optical and NIR Observations
  85. GRB 170519A: MITSuME Okayama Optical Observation
  86. GRB 170519A: NOT optical observations
  87. GRB170519A, Swift-UVOT Detection
  88. GRB 170519A: Weihai optical observations
  89. GRB 170510A: LCO Siding Springs early observations
  90. GRB 170519A: RATIR Optical and NIR Observations
  91. GRB 170519A: optical observations
  92. GRB 170519A: Enhanced Swift-XRT position
  93. GRB 170519A: Swift detection of a burst with an optical counterpart
  94. GRB 170510A CALET Gamma-Ray Burst Monitor detection
  95. LIGO/Virgo G277583: UH88/SNIFS classification of ATLAS and PS1 transients
  96. GRB 170510A: Swift-XRT afterglow detection
  97. AXP CXOU J164710.2-455216: Fermi GBM observation
  98. GRB 170516A: Swift/UVOT Upper Limits
  99. GRB 170516A: Enhanced Swift-XRT position
  100. GRB 170516A: Swift detection of a burst

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