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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"

45493 results found.

  1. IPN triangulation of GRB001219
  2. GRB 001212 Optical Observation
  3. GRB 001212 Optical Observation
  4. GRB 001212 optical observation
  5. GRB 001212 possible OA in 2MASS
  6. GRB 001212 possible OA
  7. IPN triangulation of GRB001212
  8. GRB001204: Optical observations
  9. Confirmation of IPN position for GRB001204
  10. GRB001204, Radio observations
  11. IPN triangulation of GRB001204 (short/hard)
  12. GRB 001105, further optical observations
  13. GRB001120: Gunn-i observations
  14. GRB001120: Optical observations
  15. GRB001109, optical observations
  16. GRB001120, optical observations
  17. WSRT 4.8 GHz observations of GRB001109
  18. IPN triangulation of GRB001120
  19. Optical/NIR observations of GRB001109
  20. GRB 001109: deep JHK upper limits
  21. GRB 001109 X-ray afterglow with BeppoSAX
  22. CORRECTION to XMM-Newton observation of GRB001025
  23. GRB001109: Optical observations
  24. GRB001109: BeppoSAX/NFI Observations
  25. GRB001109, R-band optical observations
  26. GRB001109, Radio observations
  27. GRB001109: BeppoSAX refined WFC position
  28. BeppoSAX ALERT: GRB001109
  29. GRB001105, BVRI field photometry
  30. GRB 001105, R-band observation
  31. IPN TRIANGULATION OF GRB001105
  32. GRB 001025B, Optical obervations
  33. GRB 991208: HST Imaging of the Host Galaxy
  34. GRB000926: R-image of the host galaxy
  35. GRB 001025B, I-band observations
  36. XMM-Newton observation of GRB001025
  37. GRB001025B, Radio observations
  38. GRB 001025 Optical Observations
  39. GRB 001025A, optical observation
  40. IPN TRIANGULATION OF GRB001025B (SHORT/HARD)
  41. CORRECTION TO IPN/RXTE ERROR BOX FOR GRB001025
  42. IPN triangulation of GRB001025
  43. GRB001007: Optical observations
  44. ASM Localization of GRB 001025
  45. GRB001007, Radio observations
  46. IPN TRIANGULATION OF GRB001020
  47. GRB001019, Optical Observations
  48. GRB 001018, Possible Radio Afterglow
  49. GRB001018, Gamma Ray Observations
  50. IPN TRIANGULATION OF GRB001019
  51. CORRECTION TO PEAK FLUX OF GRB001018
  52. IPN TRIANGULATION OF GRB001018
  53. IPN TRIANGULATION OF GRB 001017
  54. GRB 000926: Improved Absorber Redshift
  55. V,R,I band observations of GRB000926
  56. The Likely Optical/Infrared Afterglow of GRB 001011
  57. HETE positions added to GCN
  58. GRB001011 BeppoSAX/WFC refined position
  59. BeppoSAX ALERT: GRB001011
  60. GRB 001007, BVR-band observations
  61. GRB000926 - Amateur Optical Observations
  62. GRB001007: Optical observations
  63. CONCAM null result on GRB001005
  64. IPN triangulation of GRB001007
  65. GRB 000926 : the host galaxy
  66. HETE-2 Launches Successfully
  67. IPN triangulation of GRB001005
  68. HETE-2 48 hour Launch Delay
  69. GRB 000926 Chandra Observation
  70. IPN triangulation of GRB 001004
  71. Public availability of BeppoSAX data of GRB000926
  72. GRB000926: X-ray afterglow by BeppoSAX: revised fluxes (fwd)
  73. GRB000926: X-ray afterglow by BeppoSAX. Refined analysis
  74. GRB000926 - Optical observations
  75. GRB000926 - Optical observations
  76. GRB 000926, Optical Decay
  77. GRB000911: VLT infrared observation
  78. GRB000926 - Optical observations
  79. GRB000926 - Optical observations
  80. GRB 000926: optical observations
  81. GRB 000926, Optical Observations
  82. GRB000926 - Optical observations
  83. GRB000911: optical VLT observations
  84. GRB000926 K'-band Observation
  85. GRB000926 : increasing optical decay slope
  86. GRB000926 optical observations
  87. GRB000926 - Optical observations
  88. J and K band observations of GRB 000926
  89. GRB000911 Optical Observations
  90. GRB 000926: Lightcurve Update and Predictions
  91. GRB 000926, optical observation by Oksanen (vsnet-grb)
  92. GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
  93. GRB000926: Optical observations
  94. CONCAM crude optical limits before and after GRB000926
  95. GRB 000926: Preliminary R-band Lightcurve
  96. GRB 000926 HST/Chandra TOO Status
  97. Spectroscopic Redshift of GRB 000926
  98. GRB 000926, Optical Observation
  99. GRB000926, radio observations
  100. GRB 000926: Optical candidate

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