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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"

8280 results found.

  1. GRB 020321: Optical observations
  2. GRB020322: Candidate Optical Afterglow
  3. GRB 020322: Optical candidate
  4. GRB020321 optical observations
  5. GRB020305: NIR observations
  6. GRB 020305: Optical Observations
  7. GRB020305: Properties of the Candidate Optical Afterglow
  8. GRB020305: Subaru Optical Observations
  9. GRB 020305: Optical observations
  10. GRB 020305: Candidate optical afterglow
  11. GRB020127: Comparison of Chandra Epochs and Identification of Possible Counterparts
  12. GRB020127 Optical Observations
  13. IPN detection of further activity from SGR1806-20
  14. GRB optical counterpart candidate in GCN 1217 is M dwarf
  15. GRB011212: Optical observations at Gunma
  16. GRB 011211, spectrum and optical photometry
  17. GRB 011130, Radio/X-ray Comparison
  18. GRB 011212: optical observation at Oslo (relayed)
  19. GRB 011211: BVRi-band photometry
  20. GRB011212 (=H10001): An X-Ray Rich GRB Detected by HETE
  21. GRB 011130, K band observations
  22. GRB011130 (=XRF011130), Optical Observations
  23. GRB011121: UBRI Observations
  24. Optical observation of SGR 1806-20 at the 6-m SAO telescope
  25. GRB 011030 I-band Observations
  26. GRB 011030 K-band Observations
  27. GRB011019: A Faint, X-ray Rich GRB localized by HETE
  28. GRB010921, negative optical observations
  29. Probable SGR or Short Duration GRB Detected by HETE
  30. GCN and HETE status
  31. GRB 010629 Optical Observations
  32. SGR1900+14
  33. Chandra Observations of SGR 1900+14
  34. BeppoSAX GRB: extension of BSAX operations upto April 30, 2002
  35. Optical Observations of GRB 010324
  36. GRB010222 - Optical observation
  37. GRB010222 - Optical observation
  38. GRB 010214, I-band data
  39. GRB 010222
  40. GRB010222 further R-band photometry
  41. GRB010222 further R-band photometry
  42. GRB010220, Optical Observations
  43. GRB 010220: Near-IR Observations
  44. GRB010214 follow-up from Hanle
  45. GRB 010222: Near-IR Observations
  46. GRB010214, candidate optical afterglow
  47. GRB 010214, Optical Observations
  48. GRB010213, Radio Observations
  49. J-Band Observation of GRB 010214.
  50. Possible InfraRed Transient of GRB 010214.
  51. GRB010214 Optical Observation
  52. GRB 010214, optical observations
  53. GRB010213 detected by HETE
  54. HETE Status
  55. GRB010126 Optical Observations
  56. GRB 001204: Ks observations
  57. GRB 001212 possible OA in 2MASS
  58. GRB001204: Optical observations
  59. GRB001120: Gunn-i observations
  60. GRB001120: Optical observations
  61. WSRT 4.8 GHz observations of GRB001109
  62. GRB 001109: deep JHK upper limits
  63. GRB001007: Optical observations
  64. GRB001007, Radio observations
  65. HETE positions added to GCN
  66. GRB 001007, BVR-band observations
  67. GRB000911: VLT infrared observation
  68. GRB000911: optical VLT observations
  69. GRB000926 K'-band Observation
  70. J and K band observations of GRB 000926
  71. GRB000911 Optical Observations
  72. GRB 000926, optical observation by Oksanen (vsnet-grb)
  73. GRB000926: Optical observations
  74. GRB 000926, Optical Observation
  75. GRB000926, radio observations
  76. GRB 000926: Optical candidate
  77. Optical candidate for GRB000926
  78. GRB000911: Corrected coordinates
  79. GRB000911: Sub-millimeter observations
  80. GRB000911: Optical Transient
  81. GRB000911, Radio and Optical observations
  82. GRB000911: Optical observations
  83. GRB000830: Optical observations
  84. Chandra Position of GRB000210
  85. GRB000830: Optical observations
  86. HST/STIS observations of the host galaxy of GRB 980329
  87. GRB 000630: Detection of the Optical Afterglow
  88. GRB000630, Optical Observations
  89. GRB000630, optical observations
  90. GRB000630, optical observations
  91. GRB000630: Optical observations
  92. possible optical counterpart of GRB 000630
  93. GRB000604 - Optical observations
  94. GRB000604, optical observations
  95. X-ray Afterglow of GRB 000529
  96. GRB000529: Optical Observations
  97. GRB000519: Optical observations
  98. GRB 000528 Optical Observations
  99. GRB 000418, Optical observation
  100. GRB 000418, Optical Observation

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