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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"

35429 results found.

  1. IPN TRIANGULATION OF GRB010119 (SHORT/HARD)
  2. Optical observations of GRB 001018 with JCAM
  3. IPN TRIANGULATION OF GRB010115
  4. IPN TRIANGULATION OF GRB010109
  5. GRB010103, optical observations
  6. IPN triangulation of GRB010104
  7. IPN triangulation of GRB010103
  8. GRB 001204: Ks observations
  9. H band observation of GRB 001212
  10. GRB & BeppoSAX: ground operations restored back to 24 hrs a day
  11. IPN triangulation of GRB001219
  12. GRB 001212 Optical Observation
  13. GRB 001212 Optical Observation
  14. GRB 001212 optical observation
  15. GRB 001212 possible OA in 2MASS
  16. GRB 001212 possible OA
  17. IPN triangulation of GRB001212
  18. Confirmation of IPN position for GRB001204
  19. IPN triangulation of GRB001204 (short/hard)
  20. GRB 001105, further optical observations
  21. GRB001120: Gunn-i observations
  22. GRB001120: Optical observations
  23. GRB001109, optical observations
  24. GRB001120, optical observations
  25. IPN triangulation of GRB001120
  26. Optical/NIR observations of GRB001109
  27. GRB 001109: deep JHK upper limits
  28. GRB 001109 X-ray afterglow with BeppoSAX
  29. GRB001109: Optical observations
  30. GRB001109: BeppoSAX/NFI Observations
  31. GRB001109, R-band optical observations
  32. GRB001109, Radio observations
  33. BeppoSAX ALERT: GRB001109
  34. GRB001105 BVRI field photometry correction
  35. GRB001105, BVRI field photometry
  36. GRB 001105, R-band observation
  37. IPN TRIANGULATION OF GRB001105
  38. GRB 001025B, Optical obervations
  39. GRB 991208: HST Imaging of the Host Galaxy
  40. GRB000926: R-image of the host galaxy
  41. GRB 001025B, I-band observations
  42. GRB 001025 Optical Observations
  43. GRB 001025A, optical observation
  44. IPN TRIANGULATION OF GRB001025B (SHORT/HARD)
  45. IPN triangulation of GRB001025
  46. ASM Localization of GRB 001025
  47. GRB001007, Radio observations
  48. IPN TRIANGULATION OF GRB001020
  49. GRB001019, Optical Observations
  50. GRB 001018, Possible Radio Afterglow
  51. GRB001018, Gamma Ray Observations
  52. IPN TRIANGULATION OF GRB001019
  53. IPN TRIANGULATION OF GRB001018
  54. IPN TRIANGULATION OF GRB 001017
  55. GRB 000926: Improved Absorber Redshift
  56. V,R,I band observations of GRB000926
  57. The Likely Optical/Infrared Afterglow of GRB 001011
  58. HETE positions added to GCN
  59. BeppoSAX ALERT: GRB001011
  60. GRB 001007, BVR-band observations
  61. GRB000926 - Amateur Optical Observations
  62. CONCAM null result on GRB001005
  63. IPN triangulation of GRB001007
  64. GRB 000926 : the host galaxy
  65. IPN triangulation of GRB001005
  66. GRB 000926 Chandra Observation
  67. IPN triangulation of GRB 001004
  68. Public availability of BeppoSAX data of GRB000926
  69. GRB000926: X-ray afterglow by BeppoSAX. Refined analysis
  70. GRB 000926, Optical Decay
  71. GRB000926 - Optical observations
  72. GRB000926 - Optical observations
  73. GRB 000926: optical observations
  74. GRB 000926, Optical Observations
  75. GRB000926 K'-band Observation
  76. GRB000926 : increasing optical decay slope
  77. GRB000926 optical observations
  78. GRB000926 - Optical observations
  79. Re: GRB 000926, optical observation by Oksanen (vsnet-grb)
  80. J and K band observations of GRB 000926
  81. GRB 000926: Lightcurve Update and Predictions
  82. GRB 000926, optical observation by Oksanen (vsnet-grb)
  83. GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
  84. CONCAM crude optical limits before and after GRB000926
  85. GRB 000926: Preliminary R-band Lightcurve
  86. GRB 000926 HST/Chandra TOO Status
  87. Spectroscopic Redshift of GRB 000926
  88. GRB 000926, Optical Observation
  89. GRB 000926: Optical candidate
  90. Optical candidate for GRB000926
  91. IPN triangulation of GRB000926
  92. GRB 000911, BVRI field photometry
  93. GRB000911: Sub-millimeter observations
  94. IPN triangulation of GRB000925
  95. IPN triangulation of GRB000911
  96. IPN triangulation of GRB000910
  97. False GRB alarm from RXTE/ASM on 8 Sept 2000
  98. GRB 000830: Optical observations
  99. GRB000830: Optical observations
  100. GRB000830, TNG B-band observations

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