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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"

37521 results found.

  1. GRB010103, optical observations
  2. IPN triangulation of GRB010104
  3. IPN triangulation of GRB010103
  4. GRB 001204: Ks observations
  5. H band observation of GRB 001212
  6. GRB & BeppoSAX: ground operations restored back to 24 hrs a day
  7. IPN triangulation of GRB001219
  8. GRB 001212 Optical Observation
  9. GRB 001212 Optical Observation
  10. GRB 001212 optical observation
  11. GRB 001212 possible OA in 2MASS
  12. GRB 001212 possible OA
  13. IPN triangulation of GRB001212
  14. Confirmation of IPN position for GRB001204
  15. IPN triangulation of GRB001204 (short/hard)
  16. GRB 001105, further optical observations
  17. GRB001120: Gunn-i observations
  18. GRB001120: Optical observations
  19. GRB001109, optical observations
  20. GRB001120, optical observations
  21. IPN triangulation of GRB001120
  22. Optical/NIR observations of GRB001109
  23. GRB 001109: deep JHK upper limits
  24. GRB 001109 X-ray afterglow with BeppoSAX
  25. GRB001109: Optical observations
  26. GRB001109: BeppoSAX/NFI Observations
  27. GRB001109, R-band optical observations
  28. GRB001109, Radio observations
  29. BeppoSAX ALERT: GRB001109
  30. GRB001105 BVRI field photometry correction
  31. GRB001105, BVRI field photometry
  32. GRB 001105, R-band observation
  33. IPN TRIANGULATION OF GRB001105
  34. GRB 001025B, Optical obervations
  35. GRB 991208: HST Imaging of the Host Galaxy
  36. GRB000926: R-image of the host galaxy
  37. GRB 001025B, I-band observations
  38. GRB 001025 Optical Observations
  39. GRB 001025A, optical observation
  40. IPN TRIANGULATION OF GRB001025B (SHORT/HARD)
  41. IPN triangulation of GRB001025
  42. ASM Localization of GRB 001025
  43. GRB001007, Radio observations
  44. IPN TRIANGULATION OF GRB001020
  45. GRB001019, Optical Observations
  46. GRB 001018, Possible Radio Afterglow
  47. GRB001018, Gamma Ray Observations
  48. IPN TRIANGULATION OF GRB001019
  49. IPN TRIANGULATION OF GRB001018
  50. IPN TRIANGULATION OF GRB 001017
  51. GRB 000926: Improved Absorber Redshift
  52. V,R,I band observations of GRB000926
  53. The Likely Optical/Infrared Afterglow of GRB 001011
  54. HETE positions added to GCN
  55. BeppoSAX ALERT: GRB001011
  56. GRB 001007, BVR-band observations
  57. GRB000926 - Amateur Optical Observations
  58. CONCAM null result on GRB001005
  59. IPN triangulation of GRB001007
  60. GRB 000926 : the host galaxy
  61. IPN triangulation of GRB001005
  62. GRB 000926 Chandra Observation
  63. IPN triangulation of GRB 001004
  64. Public availability of BeppoSAX data of GRB000926
  65. GRB000926: X-ray afterglow by BeppoSAX. Refined analysis
  66. GRB 000926, Optical Decay
  67. GRB000926 - Optical observations
  68. GRB000926 - Optical observations
  69. GRB 000926: optical observations
  70. GRB 000926, Optical Observations
  71. GRB000926 K'-band Observation
  72. GRB000926 : increasing optical decay slope
  73. GRB000926 optical observations
  74. GRB000926 - Optical observations
  75. Re: GRB 000926, optical observation by Oksanen (vsnet-grb)
  76. J and K band observations of GRB 000926
  77. GRB 000926: Lightcurve Update and Predictions
  78. GRB 000926, optical observation by Oksanen (vsnet-grb)
  79. GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
  80. CONCAM crude optical limits before and after GRB000926
  81. GRB 000926: Preliminary R-band Lightcurve
  82. GRB 000926 HST/Chandra TOO Status
  83. Spectroscopic Redshift of GRB 000926
  84. GRB 000926, Optical Observation
  85. GRB 000926: Optical candidate
  86. Optical candidate for GRB000926
  87. IPN triangulation of GRB000926
  88. GRB 000911, BVRI field photometry
  89. GRB000911: Sub-millimeter observations
  90. IPN triangulation of GRB000925
  91. IPN triangulation of GRB000911
  92. IPN triangulation of GRB000910
  93. False GRB alarm from RXTE/ASM on 8 Sept 2000
  94. GRB 000830: Optical observations
  95. GRB000830: Optical observations
  96. GRB000830, TNG B-band observations
  97. GRB000830, BVRI field photometry
  98. GRB000830: Optical observations
  99. GRB000210, Optical observations
  100. Chandra Position of GRB000210

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