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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"

7297 results found.

  1. GRB 021113: Optical observations
  2. GRB021104: Candidate present in DSS
  3. GRB021004, Optical Observations
  4. GRB 021004: radio observations
  5. GRB 021004: Kyoto observation
  6. XRF 020903: Optical observations
  7. Second epoch K band imaging of GRB 020819
  8. GRB020819 : Optical observations at KISO
  9. GRB 020819 : OT candidate - confirmation of non variability
  10. GRB 020819: Optical observations
  11. K band observation of GRB 020819
  12. HETE 2275: Optical observations
  13. GRB020813: Fading X-ray Afterglow Observed with Chandra
  14. GRB020812: optical observations
  15. GRB020813(=H2262): Revised Localization with HETE SXC
  16. GRB 020813, radio detection
  17. GRB 020812 : optical afterglow candidate
  18. GRB020812: optical observations
  19. GRB020813, optical observations
  20. GRB020812: possible afterglow candidate
  21. GRB020812: possible afterglow candidate
  22. GRB020813, astrometric position
  23. GRB020813: Fading of Candidate OT
  24. GRB020813: Candidate Optical Afterglow
  25. GRB020801: Candidate OT present in DSS
  26. GRB020801, optical afterglow candidate
  27. GRB 020705: Optical observations
  28. GRB 020625: Optical observations
  29. GRB 020531: optical photometry of Chandra sources
  30. HETE #2081: Optical observations
  31. GRB 020531/Candidate Redshift
  32. GRB020531: Detection of Candidate Host Galaxy
  33. GRB 020603: Optical observations
  34. GRB 020531 optical observations with TAROT
  35. XRF020427: Chandra Observations and Candidate X-ray Counterparts
  36. GRB020331: Third Epoch and Revised Second Epoch Optical
  37. GRB 020418: Optical observations
  38. GRB 020418: Optical observations
  39. GRB020410: BeppoSAX NFI observations refined analysis
  40. GRB 020409: Optical observations
  41. GRB020406(?), optical observations
  42. GRB020331: Confirmation of Afterglow Candidate with Magellan
  43. GRB 020321: Candidate X-ray Counterparts
  44. ASM GRB candidate 020406 refined error box
  45. GRB020331: Optical Observations of Afterglow Candidate
  46. GRB020405: OT observations
  47. GRB 020331: Candidate Optical Afterglow
  48. GRB 020405: Decay index
  49. GRB020405, Radio Observations
  50. GRB020405: VLT spectroscopy
  51. Fading Optical Afterglow and Possible Host Galaxy of GRB 020405
  52. GRB 020405, U-band observations
  53. GRB 020405: Optical afterglow candidate
  54. GRB 020331: NIR Observations
  55. GRB020331 NIR observation at KPNO (re-submission)
  56. GRB02033 NIR observation at KPNO
  57. GRB 020331, NIR observations
  58. GRB 020331: Optical observations
  59. SN 2002ap - peak brightness date (SN/GRB?)
  60. GRB 020322: Optical Observations
  61. GRB020127: Proposed Host Galaxy Detection and Identification of Afterglow
  62. GRB 020321: Optical observations
  63. GRB020322: Candidate Optical Afterglow
  64. GRB 020322: Optical candidate
  65. GRB020305: NIR observations
  66. GRB 020305: Optical Observations
  67. GRB020305: Properties of the Candidate Optical Afterglow
  68. GRB020305: Subaru Optical Observations
  69. GRB 020305: Optical observations
  70. GRB 020305: Candidate optical afterglow
  71. GRB020127: Comparison of Chandra Epochs and Identification of Possible Counterparts
  72. GRB optical counterpart candidate in GCN 1217 is M dwarf
  73. GRB011212: Optical observations at Gunma
  74. GRB 011211, spectrum and optical photometry
  75. GRB 011212: optical observation at Oslo (relayed)
  76. GRB 011211: BVRi-band photometry
  77. GRB 011130, K band observations
  78. GRB011130 (=XRF011130), Optical Observations
  79. GRB011121: UBRI Observations
  80. GRB 011030 I-band Observations
  81. GRB 011030 K-band Observations
  82. GRB010921, negative optical observations
  83. Probable SGR or Short Duration GRB Detected by HETE
  84. GRB 010629 Optical Observations
  85. SGR1900+14
  86. Optical Observations of GRB 010324
  87. GRB 010214, I-band data
  88. GRB010222 further R-band photometry
  89. GRB010222 further R-band photometry
  90. GRB010220, Optical Observations
  91. GRB 010220: Near-IR Observations
  92. GRB010214 follow-up from Hanle
  93. GRB 010222: Near-IR Observations
  94. GRB010214, candidate optical afterglow
  95. GRB 010214, Optical Observations
  96. GRB010213, Radio Observations
  97. GRB010214 Optical Observation
  98. GRB 010214, optical observations
  99. HETE Status
  100. GRB010126 opt. obs.

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