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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"

32503 results found.

  1. AXP 1E1547.0-5408: RHESSI observations up to 400 keV
  2. GRB 090102: HST observations and host galaxy
  3. GRB 090126A: Swift-XRT Refined Analysis
  4. GRB 090118: no afterglow candidate
  5. GRB 090123: GROND detection
  6. 1E1547.0-5408: Swift detection of dust halo
  7. GRB 090123: Swift XRT refined analysis
  8. GRB 090123: Swift/UVOT Observations
  9. AXP 1E1547.0-5408: Suzaku WAM detections of the current activity
  10. GRB 090123: Swift-BAT refined analysis
  11. AXP 1E1547.0-5408: long bursts with INTEGRAL SPI-ACS
  12. GRB 090118: Swift XRT Observations - Confirmation of an Afterglow
  13. AXP 1E1547.0-5408: Fermi GBM detection of additional bursts
  14. AXP 1E1547.0-5408: INTEGRAL SPI-ACS confirms activity increase
  15. AXP 1E1547.0-5408: Fermi GBM observations
  16. Trigger 340734: Swift detection of a possible short burst
  17. GRB 090118: Subaru NIR Observation
  18. GRB 090118: KPNO 4m 2nd Epoch Observations
  19. GRB 090118 (BATSS): GRT Optical Observation
  20. GRB 090118: KPNO 4m Detection of Candidate Afterglow
  21. GRB 090118: Swift-XRT observations
  22. GRB090118 Swift/UVOT upper limits
  23. GRB 090118: GROND Upper Limits
  24. GRB 090117: confirmation of the X-ray afterglow
  25. GRB 090117 - Fermi GBM Observations
  26. GRB 090117: GROND Upper Limits
  27. GRB090117 Swift/UVOT upper limits
  28. GRB 090112B: Suzaku WAM observation of the prompt emission
  29. GRB 090113: LOAO Detection Limits in R, I, z, Y-band
  30. GRB 090113: Swift UVOT upper limits
  31. GRB 090113: GROND Upper Limits
  32. GRB 090113: Swift-XRT refined analysis
  33. GRB 090113: Observations from NOT
  34. GRB 090113: Swift-BAT refined analysis
  35. GRB 090113: ROTSE-III Optical Limits
  36. GRB090113: XRT position
  37. GRB 090111, Swift-BAT refined analysis
  38. GRB 090111: Swift UVOT Upper Limits
  39. GRB 090111: Swift-XRT refined analysis
  40. GRB 090107B: Suzaku WAM observation of the prompt emission
  41. GRB090107B: Fermi GBM Detection
  42. GRB 090102: WSRT Radio Observations
  43. GRB 090107B: Swift XRT afterglow confirmation
  44. GRB 090107B: Swift/UVOT Observations
  45. GRB 090107B: Swift-XRT detection of possible afterglow
  46. GRB 090107B optical observations
  47. GRB 090107B: ROTSE-III Optical Limits
  48. Fermi/GBM detection of GRB 081226A
  49. GRB 090107: Swift-BAT refined analysis
  50. GRB 090102: optical decay
  51. VLA radio upper limit on GRB 090102
  52. GRB 090102: GRT Optical Observation
  53. Konus-Wind observation of GRB 090102
  54. GRB 090102: Hobby-Eberly Telescope Spectroscopy
  55. GRB 090102: P60 Imaging and P200 Spectroscopy
  56. GRB 090102 Observations from IAC80
  57. GRB 090102: GROND observations of the optical afterglow
  58. Swift UVOT observations of GRB 090102
  59. GRB 090102: Swift-BAT refined analysis
  60. GRB 090102: Swift XRT refined analysis
  61. GRB 090102: NOT redshift
  62. GRB 090102: TAROT Calern observatory optical light curve
  63. GRB 090102: REM observations of a bright afterglow
  64. GRB 081230: GROND confirmation of the afterglow
  65. GRB 081230, Swift-BAT refined analysis
  66. GRB081230: Swift-XRT refined analysis
  67. GRB 081230 Swift/UVOT Observations
  68. GRB 081230: Swift/UVOT Detection of an Optical Afterglow
  69. GRB 081230: ROTSE-III Detection of Optical Counterpart
  70. GRB 081228: GROND confirmation of the optical/NIR afterglow
  71. GRB 081226B: Fermi GBM observation
  72. GRB 081228, Swift-BAT refined analysis
  73. VLA radio detection of GRB 081221
  74. GRB 081228: Swift/UVOT Upper Limits
  75. GRB 081228: Swift-XRT Team refined analysis
  76. GRB 081228: detection by GROND
  77. VLA radio observation of GRB 081221
  78. GRB 081226B: Swift XRT and UVOT upper limits
  79. GRB 081224: Suzaku WAM observation of the prompt emission
  80. GRB 081226: Swift-XRT refined analysis
  81. GRB 081226A: Swift UVOT Upper Limits
  82. GRB 081226: Second epoch of Gemini-South imaging
  83. GRB 081226A: Swift-BAT refined analysis
  84. GRB 081226: Gemini-South imaging
  85. GRB 081226: GROND afterglow candidate
  86. GRB 081226: ROTSE-III Optical Limits
  87. GRB 080810: optical observations
  88. GRB 081211B: optical observations
  89. GRB081224: LAT retraction
  90. GRB 081224: Swift-XRT observation
  91. GRB 081222: MITSuME optical observation
  92. GRB 080810: optical observations
  93. Konus-Wind observation of GRB 081222
  94. GRB 081221: GROND observations
  95. GRB 081222: Gemini-N confirmation of redshift z=2.77
  96. GRB 081222:Optical afterglow observation
  97. VLA radio upper limit on GRB 081222
  98. GRB 081222: Fermi GBM observation
  99. GRB 081222: Gemini-South absorption redshift
  100. GRB081222: Swift/UVOT further observations

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