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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"

8473 results found.

  1. GRB020305: Subaru Optical Observations
  2. GRB 020305: Optical observations
  3. GRB 020305: Candidate optical afterglow
  4. GRB020127: Comparison of Chandra Epochs and Identification of Possible Counterparts
  5. GRB020127 Optical Observations
  6. IPN detection of further activity from SGR1806-20
  7. GRB optical counterpart candidate in GCN 1217 is M dwarf
  8. GRB011212: Optical observations at Gunma
  9. GRB 011211, spectrum and optical photometry
  10. GRB 011130, Radio/X-ray Comparison
  11. GRB 011212: optical observation at Oslo (relayed)
  12. GRB 011211: BVRi-band photometry
  13. GRB011212 (=H10001): An X-Ray Rich GRB Detected by HETE
  14. GRB 011130, K band observations
  15. GRB011130 (=XRF011130), Optical Observations
  16. GRB011121: UBRI Observations
  17. Optical observation of SGR 1806-20 at the 6-m SAO telescope
  18. GRB 011030 I-band Observations
  19. GRB 011030 K-band Observations
  20. GRB011019: A Faint, X-ray Rich GRB localized by HETE
  21. GRB010921, negative optical observations
  22. Probable SGR or Short Duration GRB Detected by HETE
  23. GCN and HETE status
  24. GRB 010629 Optical Observations
  25. SGR1900+14
  26. Chandra Observations of SGR 1900+14
  27. BeppoSAX GRB: extension of BSAX operations upto April 30, 2002
  28. Optical Observations of GRB 010324
  29. GRB010222 - Optical observation
  30. GRB010222 - Optical observation
  31. GRB 010214, I-band data
  32. GRB 010222
  33. GRB010222 further R-band photometry
  34. GRB010222 further R-band photometry
  35. GRB010220, Optical Observations
  36. GRB 010220: Near-IR Observations
  37. GRB010214 follow-up from Hanle
  38. GRB 010222: Near-IR Observations
  39. GRB010214, candidate optical afterglow
  40. GRB 010214, Optical Observations
  41. GRB010213, Radio Observations
  42. J-Band Observation of GRB 010214.
  43. Possible InfraRed Transient of GRB 010214.
  44. GRB010214 Optical Observation
  45. GRB 010214, optical observations
  46. GRB010213 detected by HETE
  47. HETE Status
  48. GRB010126 Optical Observations
  49. GRB 001204: Ks observations
  50. GRB 001212 possible OA in 2MASS
  51. GRB001204: Optical observations
  52. GRB001120: Gunn-i observations
  53. GRB001120: Optical observations
  54. WSRT 4.8 GHz observations of GRB001109
  55. GRB 001109: deep JHK upper limits
  56. GRB001007: Optical observations
  57. GRB001007, Radio observations
  58. HETE positions added to GCN
  59. GRB 001007, BVR-band observations
  60. GRB000911: VLT infrared observation
  61. GRB000911: optical VLT observations
  62. GRB000926 K'-band Observation
  63. J and K band observations of GRB 000926
  64. GRB000911 Optical Observations
  65. GRB 000926, optical observation by Oksanen (vsnet-grb)
  66. GRB000926: Optical observations
  67. GRB 000926, Optical Observation
  68. GRB000926, radio observations
  69. GRB 000926: Optical candidate
  70. Optical candidate for GRB000926
  71. GRB000911: Corrected coordinates
  72. GRB000911: Sub-millimeter observations
  73. GRB000911: Optical Transient
  74. GRB000911, Radio and Optical observations
  75. GRB000911: Optical observations
  76. GRB000830: Optical observations
  77. Chandra Position of GRB000210
  78. GRB000830: Optical observations
  79. HST/STIS observations of the host galaxy of GRB 980329
  80. GRB 000630: Detection of the Optical Afterglow
  81. GRB000630, Optical Observations
  82. GRB000630, optical observations
  83. GRB000630, optical observations
  84. GRB000630: Optical observations
  85. possible optical counterpart of GRB 000630
  86. GRB000604 - Optical observations
  87. GRB000604, optical observations
  88. X-ray Afterglow of GRB 000529
  89. GRB000529: Optical Observations
  90. GRB000519: Optical observations
  91. GRB 000528 Optical Observations
  92. GRB 000418, Optical observation
  93. GRB 000418, Optical Observation
  94. GRB 000418, optical observation
  95. GRB 000418, Optical Observation
  96. GRB 000418, Optical Observation
  97. GRB 000408, optical observations
  98. GRB000301C - R magnitude lower limit
  99. GRB 000307 optical observations
  100. GRB 000313 - optical transient in the BATSE error box

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