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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"

25839 results found.

  1. GRB 020531/Candidate Redshift
  2. GRB020531: Detection of Candidate Host Galaxy
  3. GRB020531: Second epoch Chandra observations
  4. GRB020604, optical observations
  5. GRB020604, BVRcIc field photometry
  6. GRB020603, BVRcIc field observations
  7. GRB020531, BVRcIc field photometry
  8. GRB020531 Optical Observations
  9. GRB020531: Observations with the Chandra X-ray Observatory
  10. GRB020531, optical observations
  11. GRB020531: optical observations
  12. GRB020531(=H2042): Optical Observations
  13. GRB020531(=H2042): Optical Observations
  14. GRB020531: Optical observations
  15. GRB020531(=H2042): A Short, Hard Burst Localized by HETE
  16. GRB020525, optical observations
  17. HETE Observations of GX354-0 (= MXB1728-34, so-called "Slow
  18. XRF020427: Chandra Identification of a Likely X-ray Counterpart
  19. HST detection of the likely host galaxy of GRB 020124
  20. GRB020405 field photometry at ESO
  21. XRF020427: Chandra Observations and Candidate X-ray Counterparts
  22. GRB(XRF) 020427: X-ray afterglow with BeppoSAX
  23. GRB020321 : Optical observations.
  24. XRF 020427
  25. GRB 020124: Optical observations
  26. IPN triangulation of GRB020418
  27. GRB020405: VLT observations of the OT environment
  28. IPN triangulation of GRB020413
  29. GRB020405: predicted break
  30. GRB 020409: No Evidence for an Optical Afterglow
  31. GRB 020331 Kyoto observation on March 31
  32. GRB020410: BeppoSAX NFI observation
  33. X-ray afterglow of GRB020321
  34. GRB020331 optical observations with RIMOTS
  35. GRB020124 optical observations with RIBOTS/RIMOTS
  36. GRB 020321: Candidate X-ray Counterparts
  37. GRB020406(?), optical observations
  38. GRB 020405: Decay index
  39. Short RXTE/ASM transient 020406; may be a GRB
  40. GRB020405, Radio Observations
  41. GRB 020405, U-band observations
  42. GRB011212: Optical Observations
  43. GRB 020331: NIR Observations
  44. GRB020331 NIR observation at KPNO (re-submission)
  45. GRB02033 NIR observation at KPNO
  46. GRB020331 field photometry
  47. GRB 020331, NIR observations
  48. GRB020331(=H1963): The "Easter" Burst Detected by HETE
  49. GRB 020322: BeppoSAX observations of the X-ray afterglow
  50. GRB011211: HST Observations of Optical Afterglow and Host Galaxy
  51. Near-Infrared Observations of GRB020322 at TIRGO
  52. GRB 020321, Radio Observations
  53. GRB 020322: Optical Observations
  54. GRB020127: Proposed Host Galaxy Detection and Identification of Afterglow
  55. GRB 020321: Optical observations
  56. GRB020317 BVRI field photometry
  57. GRB011211 revised BVRI field photometry
  58. GRB020305 BVRI field photometry
  59. GRB020322 BVRI field photometry
  60. GRB 020322: Optical Sources and Improved Astrometry
  61. GRB020317: optical observations
  62. GRB020321 optical observations
  63. GRB020321: a faint BeppoSAX detection
  64. GRB 020317 : KISO Optical Observations
  65. GRB020317 (=H1959): Localization by HETE of a Low Fluence GRB
  66. GRB 020305: Optical Observations
  67. GRB020317, optical observations
  68. GRB 020317: Optical observations
  69. GRB 011121: Third HST Epoch
  70. GRB020305: Properties of the Candidate Optical Afterglow
  71. GRB 011121: HST Observations reveal an intermediate-time multicolor
  72. GRB011130 (XRF011130) Second Epoch Chandra Observations
  73. GRB020305: Subaru Optical Observations
  74. XRF/GRB 011030: Detection of the Probable Host Galaxy
  75. GRB 020305: Candidate optical afterglow
  76. GRB020305, optical observations
  77. IPN triangulation of GRB020305 (HETE 1939)
  78. GRB020305 (=H1939): Localization of a GRB by HETE
  79. HST Imaging of the afterglow and host of GRB 011121
  80. IPN detection and localization of Cygnus X-1 flares
  81. SGR1900+14 activity
  82. IPN Upper Limits to a GRB Associated With SN2002ap
  83. GRB020124 BVRI field photometry
  84. GRB020127: Comparison of Chandra Epochs and Identification of Possible Counterparts
  85. SN2002ap (SN/GRB?) Echelle spectra
  86. GRB020127 Optical Observations
  87. SN 2002ap in M74
  88. SN2002ap (SN/GRB?) UBVRI Field Photometry
  89. GRB020127: Chandra Observations and Prospective Counterparts
  90. pre-SN2002ap (SN/GRB?) imaging of M74
  91. Type Ib/c SN2002ap (SN/GRB?) Radio Observations
  92. GRB020124, optical observations
  93. GRB 020127, I-band observations starting 3.14-hr after the event
  94. GRB010921 Optical Observations
  95. GRB020127(=H1902): Localization of a Double-Peaked GRB by HETE
  96. GRB020124: Optical observations
  97. GRB 020124: Optical observations
  98. GRB 020124: Optical afterglow
  99. GRB020124(=H1896): Localization of a Long GRB by HETE
  100. Possible optical counterpart to a GRB

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