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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"

42757 results found.

  1. IPN TRIANGULATION OF GRB010109
  2. GRB010103, optical observations
  3. IPN triangulation of GRB010104
  4. IPN triangulation of GRB010103
  5. GRB 001204: Ks observations
  6. H band observation of GRB 001212
  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. GRB001204: Optical observations
  15. Confirmation of IPN position for GRB001204
  16. GRB001204, Radio observations
  17. IPN triangulation of GRB001204 (short/hard)
  18. GRB 001105, further optical observations
  19. GRB001120: Gunn-i observations
  20. GRB001120: Optical observations
  21. GRB001109, optical observations
  22. GRB001120, optical observations
  23. WSRT 4.8 GHz observations of GRB001109
  24. IPN triangulation of GRB001120
  25. Optical/NIR observations of GRB001109
  26. GRB 001109: deep JHK upper limits
  27. GRB 001109 X-ray afterglow with BeppoSAX
  28. CORRECTION to XMM-Newton observation of GRB001025
  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
  35. GRB 001105, R-band observation
  36. IPN TRIANGULATION OF GRB001105
  37. GRB 001025B, Optical obervations
  38. GRB 991208: HST Imaging of the Host Galaxy
  39. GRB 001025B, I-band observations
  40. XMM-Newton observation of GRB001025
  41. GRB001025B, Radio observations
  42. GRB 001025 Optical Observations
  43. GRB 001025A, optical observation
  44. IPN TRIANGULATION OF GRB001025B (SHORT/HARD)
  45. IPN triangulation of GRB001025
  46. GRB001007: Optical observations
  47. ASM Localization of GRB 001025
  48. GRB001007, Radio observations
  49. IPN TRIANGULATION OF GRB001020
  50. GRB001019, Optical Observations
  51. GRB 001018, Possible Radio Afterglow
  52. GRB001018, Gamma Ray Observations
  53. IPN TRIANGULATION OF GRB001019
  54. CORRECTION TO PEAK FLUX OF GRB001018
  55. IPN TRIANGULATION OF GRB001018
  56. IPN TRIANGULATION OF GRB 001017
  57. GRB 000926: Improved Absorber Redshift
  58. V,R,I band observations of GRB000926
  59. The Likely Optical/Infrared Afterglow of GRB 001011
  60. HETE positions added to GCN
  61. BeppoSAX ALERT: GRB001011
  62. GRB 001007, BVR-band observations
  63. GRB000926 - Amateur Optical Observations
  64. GRB001007: Optical observations
  65. CONCAM null result on GRB001005
  66. IPN triangulation of GRB001007
  67. GRB 000926 : the host galaxy
  68. HETE-2 Launches Successfully
  69. IPN triangulation of GRB001005
  70. HETE-2 48 hour Launch Delay
  71. GRB 000926 Chandra Observation
  72. IPN triangulation of GRB 001004
  73. Public availability of BeppoSAX data of GRB000926
  74. GRB000926: X-ray afterglow by BeppoSAX: revised fluxes (fwd)
  75. GRB000926: X-ray afterglow by BeppoSAX. Refined analysis
  76. GRB000926 - Optical observations
  77. GRB000926 - Optical observations
  78. GRB 000926, Optical Decay
  79. GRB000911: VLT infrared observation
  80. GRB000926 - Optical observations
  81. GRB000926 - Optical observations
  82. GRB 000926: optical observations
  83. GRB 000926, Optical Observations
  84. GRB000926 - Optical observations
  85. GRB000911: optical VLT observations
  86. GRB000926 K'-band Observation
  87. GRB000926 : increasing optical decay slope
  88. GRB000926 optical observations
  89. GRB000926 - Optical observations
  90. J and K band observations of GRB 000926
  91. GRB000911 Optical Observations
  92. GRB 000926: Lightcurve Update and Predictions
  93. GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
  94. GRB000926: Optical observations
  95. CONCAM crude optical limits before and after GRB000926
  96. GRB 000926: Preliminary R-band Lightcurve
  97. GRB 000926 HST/Chandra TOO Status
  98. Spectroscopic Redshift of GRB 000926
  99. GRB 000926, Optical Observation
  100. GRB000926, radio observations

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