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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"

32815 results found.

  1. GRB 001212 possible OA in 2MASS
  2. GRB 001212 possible OA
  3. IPN triangulation of GRB001212
  4. Confirmation of IPN position for GRB001204
  5. IPN triangulation of GRB001204 (short/hard)
  6. GRB 001105, further optical observations
  7. GRB001120: Gunn-i observations
  8. GRB001120: Optical observations
  9. GRB001109, optical observations
  10. GRB001120, optical observations
  11. IPN triangulation of GRB001120
  12. Optical/NIR observations of GRB001109
  13. GRB 001109: deep JHK upper limits
  14. GRB 001109 X-ray afterglow with BeppoSAX
  15. GRB001109: Optical observations
  16. GRB001109: BeppoSAX/NFI Observations
  17. GRB001109, R-band optical observations
  18. GRB001109, Radio observations
  19. BeppoSAX ALERT: GRB001109
  20. GRB001105 BVRI field photometry correction
  21. GRB001105, BVRI field photometry
  22. GRB 001105, R-band observation
  23. IPN TRIANGULATION OF GRB001105
  24. GRB 001025B, Optical obervations
  25. GRB 991208: HST Imaging of the Host Galaxy
  26. GRB000926: R-image of the host galaxy
  27. GRB 001025B, I-band observations
  28. GRB 001025 Optical Observations
  29. GRB 001025A, optical observation
  30. IPN TRIANGULATION OF GRB001025B (SHORT/HARD)
  31. IPN triangulation of GRB001025
  32. ASM Localization of GRB 001025
  33. GRB001007, Radio observations
  34. IPN TRIANGULATION OF GRB001020
  35. GRB001019, Optical Observations
  36. GRB 001018, Possible Radio Afterglow
  37. GRB001018, Gamma Ray Observations
  38. IPN TRIANGULATION OF GRB001019
  39. IPN TRIANGULATION OF GRB001018
  40. IPN TRIANGULATION OF GRB 001017
  41. GRB 000926: Improved Absorber Redshift
  42. V,R,I band observations of GRB000926
  43. The Likely Optical/Infrared Afterglow of GRB 001011
  44. HETE positions added to GCN
  45. BeppoSAX ALERT: GRB001011
  46. GRB 001007, BVR-band observations
  47. GRB000926 - Amateur Optical Observations
  48. CONCAM null result on GRB001005
  49. IPN triangulation of GRB001007
  50. GRB 000926 : the host galaxy
  51. IPN triangulation of GRB001005
  52. GRB 000926 Chandra Observation
  53. IPN triangulation of GRB 001004
  54. Public availability of BeppoSAX data of GRB000926
  55. GRB000926: X-ray afterglow by BeppoSAX. Refined analysis
  56. GRB 000926, Optical Decay
  57. GRB000926 - Optical observations
  58. GRB000926 - Optical observations
  59. GRB 000926: optical observations
  60. GRB 000926, Optical Observations
  61. GRB000926 K'-band Observation
  62. GRB000926 : increasing optical decay slope
  63. GRB000926 optical observations
  64. GRB000926 - Optical observations
  65. Re: GRB 000926, optical observation by Oksanen (vsnet-grb)
  66. J and K band observations of GRB 000926
  67. GRB 000926: Lightcurve Update and Predictions
  68. GRB 000926, optical observation by Oksanen (vsnet-grb)
  69. GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
  70. CONCAM crude optical limits before and after GRB000926
  71. GRB 000926: Preliminary R-band Lightcurve
  72. GRB 000926 HST/Chandra TOO Status
  73. Spectroscopic Redshift of GRB 000926
  74. GRB 000926, Optical Observation
  75. GRB 000926: Optical candidate
  76. Optical candidate for GRB000926
  77. IPN triangulation of GRB000926
  78. GRB 000911, BVRI field photometry
  79. GRB000911: Sub-millimeter observations
  80. IPN triangulation of GRB000925
  81. IPN triangulation of GRB000911
  82. IPN triangulation of GRB000910
  83. False GRB alarm from RXTE/ASM on 8 Sept 2000
  84. GRB 000830: Optical observations
  85. GRB000830: Optical observations
  86. GRB000830, TNG B-band observations
  87. GRB000830, BVRI field photometry
  88. GRB000830: Optical observations
  89. GRB000210, Optical observations
  90. Chandra Position of GRB000210
  91. "Snapshot" afterglow IDs and GRB 000830
  92. IPN triangulation of GRB000830
  93. HST/STIS observations of the host galaxy of GRB 980329
  94. HST/STIS observations of the chaotic environment of GRB 980613
  95. IPN localization of GRB000820
  96. GRB000801 & GRB000730, Gamma Ray Observations
  97. GRB000730, Gamma Ray Observations
  98. GRB000812, Radio observations
  99. IPN localization of GRB000812
  100. IPN localization of GRB000811

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