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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"

32505 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 090126A: Swift-XRT Refined Analysis
  6. GRB 090118: no afterglow candidate
  7. GRB 090123: GROND detection
  8. 1E1547.0-5408: Swift detection of dust halo
  9. GRB 090123: Swift XRT refined analysis
  10. GRB 090123: Swift/UVOT Observations
  11. AXP 1E1547.0-5408: Suzaku WAM detections of the current activity
  12. GRB 090123: Swift-BAT refined analysis
  13. AXP 1E1547.0-5408: long bursts with INTEGRAL SPI-ACS
  14. GRB 090118: Swift XRT Observations - Confirmation of an Afterglow
  15. AXP 1E1547.0-5408: Fermi GBM detection of additional bursts
  16. AXP 1E1547.0-5408: INTEGRAL SPI-ACS confirms activity increase
  17. AXP 1E1547.0-5408: Fermi GBM observations
  18. Trigger 340734: Swift detection of a possible short burst
  19. GRB 090118: Subaru NIR Observation
  20. GRB 090118: KPNO 4m 2nd Epoch Observations
  21. GRB 090118 (BATSS): GRT Optical Observation
  22. GRB 090118: KPNO 4m Detection of Candidate Afterglow
  23. GRB 090118: Swift-XRT observations
  24. GRB090118 Swift/UVOT upper limits
  25. GRB 090118: GROND Upper Limits
  26. GRB 090117: confirmation of the X-ray afterglow
  27. GRB 090117 - Fermi GBM Observations
  28. GRB 090117: GROND Upper Limits
  29. GRB090117 Swift/UVOT upper limits
  30. GRB 090112B: Suzaku WAM observation of the prompt emission
  31. GRB 090113: LOAO Detection Limits in R, I, z, Y-band
  32. GRB 090113: Swift UVOT upper limits
  33. GRB 090113: GROND Upper Limits
  34. GRB 090113: Swift-XRT refined analysis
  35. GRB 090113: Observations from NOT
  36. GRB 090113: Swift-BAT refined analysis
  37. GRB 090113: ROTSE-III Optical Limits
  38. GRB090113: XRT position
  39. GRB 090111, Swift-BAT refined analysis
  40. GRB 090111: Swift UVOT Upper Limits
  41. GRB 090111: Swift-XRT refined analysis
  42. GRB 090107B: Suzaku WAM observation of the prompt emission
  43. GRB090107B: Fermi GBM Detection
  44. GRB 090102: WSRT Radio Observations
  45. GRB 090107B: Swift XRT afterglow confirmation
  46. GRB 090107B: Swift/UVOT Observations
  47. GRB 090107B: Swift-XRT detection of possible afterglow
  48. GRB 090107B optical observations
  49. GRB 090107B: ROTSE-III Optical Limits
  50. Fermi/GBM detection of GRB 081226A
  51. GRB 090107: Swift-BAT refined analysis
  52. GRB 090102: optical decay
  53. VLA radio upper limit on GRB 090102
  54. GRB 090102: GRT Optical Observation
  55. Konus-Wind observation of GRB 090102
  56. GRB 090102: Hobby-Eberly Telescope Spectroscopy
  57. GRB 090102: P60 Imaging and P200 Spectroscopy
  58. GRB 090102 Observations from IAC80
  59. GRB 090102: GROND observations of the optical afterglow
  60. Swift UVOT observations of GRB 090102
  61. GRB 090102: Swift-BAT refined analysis
  62. GRB 090102: Swift XRT refined analysis
  63. GRB 090102: NOT redshift
  64. GRB 090102: TAROT Calern observatory optical light curve
  65. GRB 090102: REM observations of a bright afterglow
  66. GRB 081230: GROND confirmation of the afterglow
  67. GRB 081230, Swift-BAT refined analysis
  68. GRB081230: Swift-XRT refined analysis
  69. GRB 081230 Swift/UVOT Observations
  70. GRB 081230: Swift/UVOT Detection of an Optical Afterglow
  71. GRB 081230: ROTSE-III Detection of Optical Counterpart
  72. GRB 081228: GROND confirmation of the optical/NIR afterglow
  73. GRB 081226B: Fermi GBM observation
  74. GRB 081228, Swift-BAT refined analysis
  75. VLA radio detection of GRB 081221
  76. GRB 081228: Swift/UVOT Upper Limits
  77. GRB 081228: Swift-XRT Team refined analysis
  78. GRB 081228: detection by GROND
  79. VLA radio observation of GRB 081221
  80. GRB 081226B: Swift XRT and UVOT upper limits
  81. GRB 081224: Suzaku WAM observation of the prompt emission
  82. GRB 081226: Swift-XRT refined analysis
  83. GRB 081226A: Swift UVOT Upper Limits
  84. GRB 081226: Second epoch of Gemini-South imaging
  85. GRB 081226A: Swift-BAT refined analysis
  86. GRB 081226: Gemini-South imaging
  87. GRB 081226: GROND afterglow candidate
  88. GRB 081226: ROTSE-III Optical Limits
  89. GRB 080810: optical observations
  90. GRB 081211B: optical observations
  91. GRB081224: LAT retraction
  92. GRB 081224: Swift-XRT observation
  93. GRB 081222: MITSuME optical observation
  94. GRB 080810: optical observations
  95. Konus-Wind observation of GRB 081222
  96. GRB 081221: GROND observations
  97. GRB 081222: Gemini-N confirmation of redshift z=2.77
  98. GRB 081222:Optical afterglow observation
  99. VLA radio upper limit on GRB 081222
  100. GRB 081222: Fermi GBM observation

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