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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"

42203 results found.

  1. Suzaku ToO Observation of AXP 1E 1547.0-5408
  2. Konus-Wind observation of AXP/SGR 1E1547.0-5408 bursting activity
  3. AXP 1E1547.0-5408: RHESSI observations up to 400 keV
  4. GRB 090102: HST observations and host galaxy
  5. GRB 090126C: Fermi GBM detection
  6. GRB 090126A: Swift-XRT Refined Analysis
  7. GRB 090126B: Fermi GBM detection
  8. GRB 090126: SuperAGILE Localization of a Long GRB
  9. GRB 090118: no afterglow candidate
  10. 1E1547.0-5408: Swift detection of dust halo
  11. GRB 090123: Swift XRT refined analysis
  12. GRB 090123: Swift/UVOT Observations
  13. AXP 1E1547.0-5408: Suzaku WAM detections of the current activity
  14. GRB 090123: Swift-BAT refined analysis
  15. GRB090123: Enhanced Swift-XRT position
  16. GRB 090123: Swift detection of a burst
  17. AXP 1E1547.0-5408: long bursts with INTEGRAL SPI-ACS
  18. GRB 090118: Swift XRT Observations - Confirmation of an Afterglow
  19. AXP 1E1547.0-5408: Fermi GBM detection of additional bursts
  20. AXP 1E1547.0-5408: INTEGRAL SPI-ACS confirms activity increase
  21. GRB 090117C: Suzaku WAM observation of the prompt emission
  22. AXP 1E1547.0-5408: Fermi GBM observations
  23. Trigger 340734: Swift detection of a possible short burst
  24. AXP 1E1547.0-5408 activity with SGR bursts
  25. GRB 090118: Subaru NIR Observation
  26. GRB 090118 (BATSS): GRT Optical Observation
  27. GRB 090118: Swift-XRT observations
  28. GRB 090118: GROND Upper Limits
  29. GRB 090118: Possible burst detection from Swift-BAT slew data
  30. GRB 090117B : Fermi GBM detection
  31. GRB 090117: confirmation of the X-ray afterglow
  32. GRB 090117C - Fermi GRB Detection
  33. GRB 090117 - Fermi GBM Observations
  34. GRB 090117: GROND Upper Limits
  35. GRB090117 Swift/UVOT upper limits
  36. GRB090117: Swift-XRT detection of a possible candidate afterglow
  37. GRB 090117 - SuperAGILE Localization of a long GRB
  38. GRB090102: MAGIC telescope GeV observation
  39. GRB 090112B: Suzaku WAM observation of the prompt emission
  40. GRB 090113: LOAO Detection Limits in R, I, z, Y-band
  41. GRB 090113: GROND Upper Limits
  42. GRB 090113: Swift-XRT refined analysis
  43. GRB 090113: Observations from NOT
  44. GRB 090113: Enhanced Swift-XRT position
  45. GRB 090113: Swift-BAT refined analysis
  46. GRB 090113: ROTSE-III Optical Limits
  47. GRB090113: XRT position
  48. GRB 090112B: Fermi GBM Detection
  49. GRB 090113: Swift detection of a burst
  50. GRB 090112: Fermi GBM detection
  51. GRB 090109: Fermi GBM detection
  52. GRB 090108B: Fermi GBM detection
  53. GRB 090111, Swift-BAT refined analysis
  54. GRB 090108: Fermi GBM Detection
  55. GRB 090111: Swift-XRT refined analysis
  56. GRB 090111: Enhanced Swift-XRT position
  57. GRB 090111: Swift detection of a burst
  58. GRB 090107B: Suzaku WAM observation of the prompt emission
  59. GRB090107B: Fermi GBM Detection
  60. GRB 090102: WSRT Radio Observations
  61. GRB 090107B: Swift XRT afterglow confirmation
  62. GRB 090107B: Swift/UVOT Observations
  63. GRB 090107B: Swift-XRT detection of possible afterglow
  64. GRB 090107B optical observations
  65. GRB 090107B: ROTSE-III Optical Limits
  66. GRB 090107B: a long GRB localized by INTEGRAL
  67. Fermi/GBM detection of GRB 081226A
  68. Fermi/GBM detection of GRB 081225
  69. GRB 090107: Swift-BAT refined analysis
  70. GRB 090107: Swift detection of a burst
  71. GRB 081231: Fermi GBM Detection
  72. GRB 090102: optical decay
  73. GRB 090102: GRT Optical Observation
  74. Swift triggered on the HMXB 1A 1118-61
  75. Konus-Wind observation of GRB 090102
  76. GRB 081229: Fermi GBM detection
  77. GRB 090102: Hobby-Eberly Telescope Spectroscopy
  78. GRB 090102: P60 Imaging and P200 Spectroscopy
  79. GRB 090102 Observations from IAC80
  80. GRB 090102: GROND observations of the optical afterglow
  81. Swift UVOT observations of GRB 090102
  82. GRB 090102: Swift-BAT refined analysis
  83. GRB 090102: Swift XRT refined analysis
  84. GRB 090102: NOT redshift
  85. GRB 090102: Enhanced Swift-XRT position
  86. GRB 090102: TAROT Calern observatory optical light curve
  87. GRB 090102: REM observations of a bright afterglow
  88. GRB 090102: Swift detection of a burst with an optical counterpart
  89. GRB 090102: TAROT Calern observatory optical observations
  90. GRB 081230: GROND confirmation of the afterglow
  91. GRB 081230, Swift-BAT refined analysis
  92. GRB081230: Swift-XRT refined analysis
  93. GRB 081230 Swift/UVOT Observations
  94. GRB 081230: Enhanced Swift-XRT position
  95. GRB 081230: Swift/UVOT Detection of an Optical Afterglow
  96. GRB 081230: ROTSE-III Detection of Optical Counterpart
  97. GRB 081230: Swift detection of a burst
  98. GRB 081228: GROND confirmation of the optical/NIR afterglow
  99. GRB 081226B: Fermi GBM observation
  100. GRB 081226C: Fermi GBM detection

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