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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"

37513 results found.

  1. GRB 001212 Optical Observation
  2. GRB 001212 optical observation
  3. GRB 001212 possible OA in 2MASS
  4. GRB 001212 possible OA
  5. IPN triangulation of GRB001212
  6. Confirmation of IPN position for GRB001204
  7. IPN triangulation of GRB001204 (short/hard)
  8. GRB 001105, further optical observations
  9. GRB001120: Gunn-i observations
  10. GRB001120: Optical observations
  11. GRB001109, optical observations
  12. GRB001120, optical observations
  13. IPN triangulation of GRB001120
  14. Optical/NIR observations of GRB001109
  15. GRB 001109: deep JHK upper limits
  16. GRB 001109 X-ray afterglow with BeppoSAX
  17. GRB001109: Optical observations
  18. GRB001109: BeppoSAX/NFI Observations
  19. GRB001109, R-band optical observations
  20. GRB001109, Radio observations
  21. BeppoSAX ALERT: GRB001109
  22. GRB001105 BVRI field photometry correction
  23. GRB001105, BVRI field photometry
  24. GRB 001105, R-band observation
  25. IPN TRIANGULATION OF GRB001105
  26. GRB 001025B, Optical obervations
  27. GRB 991208: HST Imaging of the Host Galaxy
  28. GRB000926: R-image of the host galaxy
  29. GRB 001025B, I-band observations
  30. GRB 001025 Optical Observations
  31. GRB 001025A, optical observation
  32. IPN TRIANGULATION OF GRB001025B (SHORT/HARD)
  33. IPN triangulation of GRB001025
  34. ASM Localization of GRB 001025
  35. GRB001007, Radio observations
  36. IPN TRIANGULATION OF GRB001020
  37. GRB001019, Optical Observations
  38. GRB 001018, Possible Radio Afterglow
  39. GRB001018, Gamma Ray Observations
  40. IPN TRIANGULATION OF GRB001019
  41. IPN TRIANGULATION OF GRB001018
  42. IPN TRIANGULATION OF GRB 001017
  43. GRB 000926: Improved Absorber Redshift
  44. V,R,I band observations of GRB000926
  45. The Likely Optical/Infrared Afterglow of GRB 001011
  46. HETE positions added to GCN
  47. BeppoSAX ALERT: GRB001011
  48. GRB 001007, BVR-band observations
  49. GRB000926 - Amateur Optical Observations
  50. CONCAM null result on GRB001005
  51. IPN triangulation of GRB001007
  52. GRB 000926 : the host galaxy
  53. IPN triangulation of GRB001005
  54. GRB 000926 Chandra Observation
  55. IPN triangulation of GRB 001004
  56. Public availability of BeppoSAX data of GRB000926
  57. GRB000926: X-ray afterglow by BeppoSAX. Refined analysis
  58. GRB 000926, Optical Decay
  59. GRB000926 - Optical observations
  60. GRB000926 - Optical observations
  61. GRB 000926: optical observations
  62. GRB 000926, Optical Observations
  63. GRB000926 K'-band Observation
  64. GRB000926 : increasing optical decay slope
  65. GRB000926 optical observations
  66. GRB000926 - Optical observations
  67. Re: GRB 000926, optical observation by Oksanen (vsnet-grb)
  68. J and K band observations of GRB 000926
  69. GRB 000926: Lightcurve Update and Predictions
  70. GRB 000926, optical observation by Oksanen (vsnet-grb)
  71. GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
  72. CONCAM crude optical limits before and after GRB000926
  73. GRB 000926: Preliminary R-band Lightcurve
  74. GRB 000926 HST/Chandra TOO Status
  75. Spectroscopic Redshift of GRB 000926
  76. GRB 000926, Optical Observation
  77. GRB 000926: Optical candidate
  78. Optical candidate for GRB000926
  79. IPN triangulation of GRB000926
  80. GRB 000911, BVRI field photometry
  81. GRB000911: Sub-millimeter observations
  82. IPN triangulation of GRB000925
  83. IPN triangulation of GRB000911
  84. IPN triangulation of GRB000910
  85. False GRB alarm from RXTE/ASM on 8 Sept 2000
  86. GRB 000830: Optical observations
  87. GRB000830: Optical observations
  88. GRB000830, TNG B-band observations
  89. GRB000830, BVRI field photometry
  90. GRB000830: Optical observations
  91. GRB000210, Optical observations
  92. Chandra Position of GRB000210
  93. "Snapshot" afterglow IDs and GRB 000830
  94. IPN triangulation of GRB000830
  95. HST/STIS observations of the host galaxy of GRB 980329
  96. HST/STIS observations of the chaotic environment of GRB 980613
  97. IPN localization of GRB000820
  98. GRB000801 & GRB000730, Gamma Ray Observations
  99. GRB000730, Gamma Ray Observations
  100. GRB000812, Radio observations

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