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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"

2626 results found.

  1. GRB070227: possible X-ray afterglow detection
  2. GRB 920925C: optical afterglow candidate
  3. VLA observation of GRB 070223
  4. GRB070224: Swift-XRT Refined Analysis
  5. GRB 070223: Swift-XRT Refined Analysis
  6. GRB 070223: Liverpool Telescope Possible Afterglow Candidate
  7. GRB 070125 observations with the GMRT
  8. GRB 070208: MDM Optical Decay
  9. GRB070126: Swift-XRT Observation
  10. GRB 070125: optical observation
  11. GRB 070129, Swift-BAT refined analysis of a particularly long
  12. GRB 070126: VLT observations
  13. GRB070126: Swift-XRT possible detection of an afterglow
  14. Possible GRB 070126: Swift/UVOT Upper Limit
  15. GRB070125: Swift-XRT Refined Analysis
  16. GRB 070126?: Swift detection of a possible burst
  17. GRB 070110: Continued Detection and Request for Ground Followup
  18. GRB 070110: Ep,i - Eiso correlation
  19. Trigger 255685: Swift detection of a possible burst
  20. GRB 070110: Swift detection of a burst with a possible optical afterglow
  21. GRB 070107: Possible UVOT Afterglow
  22. Retractions of previous Swift-BAT triggers
  23. GRB 061210: Possible Host Galaxy (S2-G2) Keck Spectrum
  24. GRB 061218: REM prompt observations
  25. Swift triggers (#251863) on a possible burst
  26. GRB 061210: MDM Follow-up Observation
  27. GRB 061210: Swift XRT analysis - Possible counterparts
  28. GRB 061214(?): ROTSE-III Optical Limits
  29. GRB 061214(?): Swift detection of a possible burst
  30. GRB 061210: Swift-BAT detection of a short burst
  31. GRB061126: update on the Swift-XRT afterglow light curve
  32. GRB 061201: Initial UVOT Observations
  33. GRB 061126: Possible Jet Break
  34. GRB 061110B: Swift/XRT position
  35. GRB 061110B : Liverpool Telescope Optical Afterglow Detection
  36. GRB 061109: optical observation
  37. GRB 061109: Swift detection of a possible burst
  38. GRB 061102B: Swift detection of a possible burst
  39. GRB 061027, Swift refined analysis of a possible burst
  40. GRB 061027: Swift detection of a possible burst
  41. GRB061019: Swift XRT refined analysis
  42. GRB 060928: Swift observations
  43. GRB 060908: Detection of a possible host
  44. GRB 060807: Detection of a possible host galaxy
  45. GRB 060729: An update on the late-time Swift observations
  46. GRB 060927: Possible host galaxy (star?) in the SDSS
  47. GRB 060923, Swift-BAT refined analysis
  48. GRB 060919: Swift detection of a burst
  49. GRB 060912: Swift detection of a burst with an optical afterglow
  50. GRB 060906 (?): P60 Optical Afterglow Candidate
  51. GRB 060906: Swift detection of a probable burst
  52. GRB 060901: SMARTS optical/IR observations update
  53. GRB 060826(?): Swift detection of a possible burst
  54. GRB060813: Break in the XRT light curve
  55. GRB 060814: P200 NIR Observations
  56. GRB 060814: Possible IR counterpart
  57. GRB060807: Possible Highly Significant X-ray Emission Lines
  58. GRB 060729: An update on the Swift XRT and UVOT observations
  59. GRB 060804: Swift detection of a burst with a possible UVOT counterpart
  60. GRB 060801: optical observations at FORS2/VLT
  61. GRB 060801: Refined analysis of the Swift-BAT short hard burst
  62. GRB 060729: Swift detection of a burst with an UVOT optical counterpart
  63. GRB 060719: prompt PROMPT observations
  64. GRB 060719: VLT observations
  65. GRB 060714: OA fading and a possible host detection
  66. GRB 060714: REM infrared observations
  67. GRB 060714 : Liverpool Telescope Observations
  68. Correction to Circular 5314: Circular refers to GRB 060714
  69. GRB060707 possible optical confirmation
  70. GRB060707 possible optical confirmation
  71. GRB060614: Possible SN Bump in UVOT U Band Light Curve
  72. GRB 060614: Detection of a Possible, Late-Time Rebrightening
  73. Trigger 215279: Swift detection of a possible burst (GRB 060619)
  74. GRB050124: Possible Host Galaxy
  75. GRB 060602A: Swift/XRT analysis
  76. GRB 060604: Swift detection of a burst with possible optical counterpart
  77. GRB 060602A: Swift-BAT Refined Analysis: Correction
  78. GRB 060602B: XMM-Newton Survey Source
  79. GRB060602B: BOOTES-IR candidate afterglow
  80. GRB060526: possible break in the optical light curve
  81. GRB 060526: Optical Flare
  82. GRB060505: VLT observations of the optical afterglow
  83. GRB 060522: Swift detection of a burst with possible optical afterglow
  84. GRB 060512: reanalysis of optical spectra
  85. GRB 060515: NIR observation
  86. GRB060515: P200 NIR Observations
  87. GRB 060515 BAT refined analysis
  88. GRB 060515: Swift/XRT Team refined analysis
  89. GRB 060515: Swift/XRT position
  90. GRB 060515: TAROT optical observation
  91. GRB060418: optical observations
  92. GRB 060510B: Swift detection of a burst
  93. GRB060502B: improvement in the XRT afterglow position
  94. GRB 060505: Swift XRT Team Refined Analysis
  95. GRB 060502B: Refined analysis of the Swift-BAT short burst
  96. Short GRB 060502B: Tautenburg Observation
  97. GRB 060502B: Swift detection of a short burst
  98. GRB 060501: MDM Observations
  99. GRB060428B: possible detection of an optical counterpart by Swift/UVOT.
  100. GRB 060428: Swift detection of a burst

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