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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"

25043 results found.

  1. GRB 020531, INT+WFC deep optical upper limits
  2. SGR-like Bursts from the AXP 1E 2259+586
  3. GRB020405: polarimetric observations
  4. GRB 020531, simultaneous optical observations
  5. GRB 020531/Candidate Redshift
  6. GRB020531: Detection of Candidate Host Galaxy
  7. GRB020531: Second epoch Chandra observations
  8. GRB020604, optical observations
  9. GRB020604, BVRcIc field photometry
  10. GRB020603, BVRcIc field observations
  11. GRB020531, BVRcIc field photometry
  12. GRB020531 Optical Observations
  13. GRB020531: Observations with the Chandra X-ray Observatory
  14. GRB020531, optical observations
  15. GRB020531: optical observations
  16. GRB020531(=H2042): Optical Observations
  17. GRB020531(=H2042): Optical Observations
  18. GRB020531: Optical observations
  19. GRB020531(=H2042): A Short, Hard Burst Localized by HETE
  20. GRB020525, optical observations
  21. HETE Observations of GX354-0 (= MXB1728-34, so-called "Slow
  22. XRF020427: Chandra Identification of a Likely X-ray Counterpart
  23. HST detection of the likely host galaxy of GRB 020124
  24. GRB020405 field photometry at ESO
  25. XRF020427: Chandra Observations and Candidate X-ray Counterparts
  26. GRB(XRF) 020427: X-ray afterglow with BeppoSAX
  27. GRB020321 : Optical observations.
  28. XRF 020427
  29. GRB 020124: Optical observations
  30. IPN triangulation of GRB020418
  31. GRB020405: VLT observations of the OT environment
  32. IPN triangulation of GRB020413
  33. GRB020405: predicted break
  34. GRB 020409: No Evidence for an Optical Afterglow
  35. GRB 020331 Kyoto observation on March 31
  36. GRB020410: BeppoSAX NFI observation
  37. X-ray afterglow of GRB020321
  38. GRB020331 optical observations with RIMOTS
  39. GRB020124 optical observations with RIBOTS/RIMOTS
  40. GRB 020321: Candidate X-ray Counterparts
  41. GRB020406(?), optical observations
  42. GRB 020405: Decay index
  43. Short RXTE/ASM transient 020406; may be a GRB
  44. GRB020405, Radio Observations
  45. GRB 020405, U-band observations
  46. GRB011212: Optical Observations
  47. GRB 020331: NIR Observations
  48. GRB020331 NIR observation at KPNO (re-submission)
  49. GRB02033 NIR observation at KPNO
  50. GRB020331 field photometry
  51. GRB 020331, NIR observations
  52. GRB020331(=H1963): The "Easter" Burst Detected by HETE
  53. GRB 020322: BeppoSAX observations of the X-ray afterglow
  54. GRB011211: HST Observations of Optical Afterglow and Host Galaxy
  55. Near-Infrared Observations of GRB020322 at TIRGO
  56. GRB 020321, Radio Observations
  57. GRB 020322: Optical Observations
  58. GRB020127: Proposed Host Galaxy Detection and Identification of Afterglow
  59. GRB 020321: Optical observations
  60. GRB020317 BVRI field photometry
  61. GRB011211 revised BVRI field photometry
  62. GRB020305 BVRI field photometry
  63. GRB020322 BVRI field photometry
  64. GRB 020322: Optical Sources and Improved Astrometry
  65. GRB020317: optical observations
  66. GRB020321 optical observations
  67. GRB020321: a faint BeppoSAX detection
  68. GRB 020317 : KISO Optical Observations
  69. GRB020317 (=H1959): Localization by HETE of a Low Fluence GRB
  70. GRB 020305: Optical Observations
  71. GRB020317, optical observations
  72. GRB 020317: Optical observations
  73. GRB 011121: Third HST Epoch
  74. GRB020305: Properties of the Candidate Optical Afterglow
  75. GRB 011121: HST Observations reveal an intermediate-time multicolor
  76. GRB011130 (XRF011130) Second Epoch Chandra Observations
  77. GRB020305: Subaru Optical Observations
  78. XRF/GRB 011030: Detection of the Probable Host Galaxy
  79. GRB 020305: Candidate optical afterglow
  80. GRB020305, optical observations
  81. IPN triangulation of GRB020305 (HETE 1939)
  82. GRB020305 (=H1939): Localization of a GRB by HETE
  83. HST Imaging of the afterglow and host of GRB 011121
  84. IPN detection and localization of Cygnus X-1 flares
  85. SGR1900+14 activity
  86. IPN Upper Limits to a GRB Associated With SN2002ap
  87. GRB020124 BVRI field photometry
  88. GRB020127: Comparison of Chandra Epochs and Identification of Possible Counterparts
  89. SN2002ap (SN/GRB?) Echelle spectra
  90. GRB020127 Optical Observations
  91. SN 2002ap in M74
  92. SN2002ap (SN/GRB?) UBVRI Field Photometry
  93. GRB020127: Chandra Observations and Prospective Counterparts
  94. pre-SN2002ap (SN/GRB?) imaging of M74
  95. Type Ib/c SN2002ap (SN/GRB?) Radio Observations
  96. GRB020124, optical observations
  97. GRB 020127, I-band observations starting 3.14-hr after the event
  98. GRB010921 Optical Observations
  99. GRB020127(=H1902): Localization of a Double-Peaked GRB by HETE
  100. GRB020124: Optical observations

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