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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"

3036 results found.

  1. MASTER: HETE Alert 3274 optical observation
  2. GRB040511: Candidate optical/NIR afterglow
  3. GRB 040319 (=H3128): An X-Ray-Rich GRB Localized by the HETE-2 WXM and SXC
  4. GRB 040228 (=H3066?,=H3067?): A Long GRB Localized by the HETE-2 WXM
  5. GRB031220: 2nd Chandra observation and X-ray afterglow candidate
  6. GRB040106: refined X-ray transient position
  7. GRB040106, Radio Observations
  8. GRB040106, likely optical afterglow
  9. GRB 040106: Optical observations
  10. XMM-Newton observation of GRB040106
  11. GRB 040106 : Planned XMM-Newton observation
  12. GRB 040106 : a long GRB detected with INTEGRAL
  13. GRB031220: Palomar Observations
  14. GRB 031203: IR NTTobservations do not confirm REM detection
  15. SN 2003jd (SN/GRB?) -- X-ray Observations
  16. IPN triangulation of GRB031016 (two large error boxes)
  17. XRF030824 (=H2821): An X-Ray Flash Localized by the HETE WXM
  18. IPN triangulation of GRB030921 (large error box)
  19. IPN triangulation of GRB030806 (large burst; large error box)
  20. XRF030723, ROTSE-III Early Observations
  21. XRF030723, optical observations
  22. XRF030723 (=H2777): An X-ray Flash Localized by the HETE WXM and
  23. IPN triangulation of GRB030715 (two large error boxes)
  24. GRB030329 -- RATAN-600 data in April-May
  25. GRB 030329: Optical limit (contemporaneous imaging)
  26. XRF030416 (=U10897): An X-Ray Flash Localized by the HETE WXM
  27. IPN triangulation of GRB030425 (single error box)
  28. GRB 030329, the review of the sky area in plate archive (1950-1998)
  29. IPN triangulation of GRB030422 (two large error boxes)
  30. GRB030329: 444 AAVSO Measurements
  31. GRB 030329, nearby galaxies
  32. Further AAVSO V,B,R observations of GRB030329
  33. GRB 030329: Correction to GCN 2056
  34. GRB 030329: optical observations
  35. GRB030323, ROTSE-III detection of possible optical counterpart
  36. GRB030323, possible optical counterpart
  37. IPN triangulation of GRB030320 (small error box)
  38. GRB030226 (=U10893): A Long GRB Localized by the HETE WXM and SXC
  39. GRB 030217: Optical Observations at 4, 5, and 6 Days
  40. GRB030131: Kiso Observations
  41. IPN triangulation of GRB030101 (two large error boxes)
  42. GRB021004, late time optical observations
  43. Improved IPN error box for GRB021125
  44. IPN BURST POSITION
  45. IPN triangulation of GRB021125 (INTEGRAL BURST)
  46. GRB021104(=H2434): A Long, X-Ray-Rich GRB Localized by HETE
  47. GRB021104: optical observations
  48. GRB021104: possible optical afterglow
  49. IPN triangulation of GRB021027 (single large error box)
  50. GRB021004, late-time optical observations
  51. GRB 021004: optical observations
  52. IPN triangulation of GRB021020
  53. GRB021016(=H2397): A Long GRB Localized by HETE
  54. IPN triangulation of GRB021016 (small error box)
  55. IPN triangulation of GRB021008 (two small error boxes)
  56. GRB021004: optical observations and predicted break time
  57. GRB021004: BVRc photometry
  58. GRB 021004: optical counterpart
  59. GRB 021004, SPM optical observations
  60. IPN triangulation of GRB020923 (two error boxes)
  61. Confirmation of IPN error box for GRB020910
  62. IPN triangulation of GRB020910
  63. GRB020903(=H2314): An X-Ray Flash Localized by HETE
  64. INTEGRAL GRBs added to GCN
  65. IPN error box for GRB020813
  66. GRB020813: Candidate Optical Afterglow
  67. Correction to IPN error box for GRB020706
  68. GRB 020625, optical observations
  69. GRB 020531: optical photometry of Chandra sources
  70. GRB020604, optical observations
  71. GRB020531: Observations with the Chandra X-ray Observatory
  72. Correction to IPN triangulation of GRB020603 (possible short/hard burst)
  73. GRB 020124: Optical observations
  74. GRB 020331 Kyoto observation on March 31
  75. GRB020317: optical observations
  76. GRB020321 optical observations
  77. IPN Upper Limits to a GRB Associated With SN2002ap
  78. GRB020127: Comparison of Chandra Epochs and Identification of Possible Counterparts
  79. GRB020127: Chandra Observations and Prospective Counterparts
  80. GRB 011211, Optical Observations
  81. GRB011130 (=XRF011130): Further analysis of Chandra Target of
  82. GRB011130 (XRF011130) Chandra Observations
  83. GRB011121: fainter still
  84. BEPPOSAX GRB011121
  85. XRF011030: Chandra Observations
  86. Millimeter observation of SGR 1900+14
  87. IPN Triangulation of GRB010412
  88. GRB010214, candidate optical afterglow
  89. GRB010214 Optical Observation
  90. IPN TRIANGULATION OF GRB010109
  91. IPN TRIANGULATION OF GRB010109
  92. XMM-Newton observation of GRB001025
  93. IPN TRIANGULATION OF GRB001020
  94. IPN TRIANGULATION OF GRB001018
  95. GRB000926 - Amateur Optical Observations
  96. GRB 000926 Chandra Observation
  97. GRB000926: X-ray afterglow by BeppoSAX. Refined analysis
  98. J and K band observations of GRB 000926
  99. GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
  100. GRB 000926, Optical Observation

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