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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"

7408 results found.

  1. GRB 030115, no optical candidate
  2. GRB 030115, optical candidate
  3. GRB 021112: Evidence for Another Dark Optical Afterglow
  4. XRF 020903 : HST observations
  5. GRB021204: Kiso Observations
  6. GRB021211 (=H2493): A Bright, Long GRB Localized by HETE-2 in Near-Real Time
  7. HETE 2493: Optical observations
  8. HETE 2493: Optical candidate
  9. GRB 021112: Afterglow or Variable Star?
  10. GRB 021112, Radio Observations
  11. GRB 021112: Variable Source in R-band search
  12. GRB 021113: Optical observations
  13. GRB021104: Candidate present in DSS
  14. GRB021004, Optical Observations
  15. GRB 021004: radio observations
  16. GRB 021004: Kyoto observation
  17. XRF 020903: Optical observations
  18. Second epoch K band imaging of GRB 020819
  19. GRB020819 : Optical observations at KISO
  20. GRB 020819 : OT candidate - confirmation of non variability
  21. GRB 020819: Optical observations
  22. K band observation of GRB 020819
  23. HETE 2275: Optical observations
  24. GRB020813: Fading X-ray Afterglow Observed with Chandra
  25. GRB020812: optical observations
  26. GRB020813(=H2262): Revised Localization with HETE SXC
  27. GRB 020813, radio detection
  28. GRB 020812 : optical afterglow candidate
  29. GRB020812: optical observations
  30. GRB020813, optical observations
  31. GRB020812: possible afterglow candidate
  32. GRB020812: possible afterglow candidate
  33. GRB020813, astrometric position
  34. GRB020813: Fading of Candidate OT
  35. GRB020813: Candidate Optical Afterglow
  36. GRB020801: Candidate OT present in DSS
  37. GRB020801, optical afterglow candidate
  38. GRB 020705: Optical observations
  39. GRB 020625: Optical observations
  40. GRB 020531: optical photometry of Chandra sources
  41. HETE #2081: Optical observations
  42. GRB 020531/Candidate Redshift
  43. GRB020531: Detection of Candidate Host Galaxy
  44. GRB 020603: Optical observations
  45. GRB 020531 optical observations with TAROT
  46. XRF020427: Chandra Observations and Candidate X-ray Counterparts
  47. GRB020331: Third Epoch and Revised Second Epoch Optical
  48. GRB 020418: Optical observations
  49. GRB 020418: Optical observations
  50. GRB020410: BeppoSAX NFI observations refined analysis
  51. GRB 020409: Optical observations
  52. GRB020406(?), optical observations
  53. GRB020331: Confirmation of Afterglow Candidate with Magellan
  54. GRB 020321: Candidate X-ray Counterparts
  55. ASM GRB candidate 020406 refined error box
  56. GRB020331: Optical Observations of Afterglow Candidate
  57. GRB020405: OT observations
  58. GRB 020331: Candidate Optical Afterglow
  59. GRB 020405: Decay index
  60. GRB020405, Radio Observations
  61. GRB020405: VLT spectroscopy
  62. Fading Optical Afterglow and Possible Host Galaxy of GRB 020405
  63. GRB 020405, U-band observations
  64. GRB 020405: Optical afterglow candidate
  65. GRB 020331: NIR Observations
  66. GRB020331 NIR observation at KPNO (re-submission)
  67. GRB02033 NIR observation at KPNO
  68. GRB 020331, NIR observations
  69. GRB 020331: Optical observations
  70. SN 2002ap - peak brightness date (SN/GRB?)
  71. GRB 020322: Optical Observations
  72. GRB020127: Proposed Host Galaxy Detection and Identification of Afterglow
  73. GRB 020321: Optical observations
  74. GRB020322: Candidate Optical Afterglow
  75. GRB 020322: Optical candidate
  76. GRB020305: NIR observations
  77. GRB 020305: Optical Observations
  78. GRB020305: Properties of the Candidate Optical Afterglow
  79. GRB020305: Subaru Optical Observations
  80. GRB 020305: Optical observations
  81. GRB 020305: Candidate optical afterglow
  82. GRB020127: Comparison of Chandra Epochs and Identification of Possible Counterparts
  83. GRB optical counterpart candidate in GCN 1217 is M dwarf
  84. GRB011212: Optical observations at Gunma
  85. GRB 011211, spectrum and optical photometry
  86. GRB 011212: optical observation at Oslo (relayed)
  87. GRB 011211: BVRi-band photometry
  88. GRB 011130, K band observations
  89. GRB011130 (=XRF011130), Optical Observations
  90. GRB011121: UBRI Observations
  91. GRB 011030 I-band Observations
  92. GRB 011030 K-band Observations
  93. GRB010921, negative optical observations
  94. Probable SGR or Short Duration GRB Detected by HETE
  95. GRB 010629 Optical Observations
  96. SGR1900+14
  97. Optical Observations of GRB 010324
  98. GRB 010214, I-band data
  99. GRB010222 further R-band photometry
  100. GRB010222 further R-band photometry

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