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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"

24809 results found.

  1. GRB010214, field photometry
  2. GRB010222, field photometry
  3. GRB010222 further R-band photometry
  4. GRB010222, possible increase of optical decay slope
  5. GRB 010222 Kyoto optical observation
  6. GRB010222 R-BAND OBSERVATION
  7. GRB010214 follow-up from Hanle
  8. GRB 010222: Near-IR Observations
  9. GRB 010222: Optical Observations
  10. GRB010222: Optical decay slope
  11. GRB 010214, Optical Observations
  12. GRB010222, radio observations
  13. GRB010222, optical observations
  14. GRB010222: BeppoSAX/NFI Observations
  15. GRB010214B,Gamma Ray Observations
  16. GRB 010220, simultaneous optical observations
  17. GRB010220: BeppoSAX WFC and GRBM preliminary data
  18. GRB010214, candidate optical afterglow
  19. GRB010214, optical observations
  20. GRB010214: BeppoSAX WFC and GRBM preliminary data
  21. GRB 010214: X-Ray afterglow
  22. GRB 010214 optical observation
  23. GRB010213, Radio Observations
  24. J-Band Observation of GRB 010214.
  25. GRB010213, Near-IR observations
  26. Possible InfraRed Transient of GRB 010214.
  27. GRB 010214, optical observations
  28. GRB010213 detected by HETE
  29. IPN Status Report
  30. HETE Status
  31. IPN/RXTE TRIANGULATION OF GRB010126
  32. GRB010126 Optical Observations
  33. IPN TRIANGULATION OF GRB010126
  34. Optical Observations of GRB 001018 at Keck
  35. IPN TRIANGULATION OF GRB010119 (SHORT/HARD)
  36. Optical observations of GRB 001018 with JCAM
  37. IPN TRIANGULATION OF GRB010115
  38. IPN TRIANGULATION OF GRB010109
  39. IPN TRIANGULATION OF GRB010109
  40. IPN triangulation of GRB010104
  41. IPN triangulation of GRB010103
  42. H band observation of GRB 001212
  43. IPN triangulation of GRB001219
  44. GRB 001212 Optical Observation
  45. GRB 001212 Optical Observation
  46. GRB 001212 possible OA in 2MASS
  47. IPN triangulation of GRB001212
  48. Confirmation of IPN position for GRB001204
  49. IPN triangulation of GRB001204 (short/hard)
  50. GRB001120, optical observations
  51. WSRT 4.8 GHz observations of GRB001109
  52. IPN triangulation of GRB001120
  53. GRB 001109: deep JHK upper limits
  54. GRB 001109 X-ray afterglow with BeppoSAX
  55. CORRECTION to XMM-Newton observation of GRB001025
  56. GRB001109, Radio observations
  57. GRB001105 BVRI field photometry correction
  58. GRB001105, BVRI field photometry
  59. IPN TRIANGULATION OF GRB001105
  60. GRB 001025B, Optical obervations
  61. GRB 991208: HST Imaging of the Host Galaxy
  62. GRB 001025B, I-band observations
  63. XMM-Newton observation of GRB001025
  64. IPN TRIANGULATION OF GRB001025B (SHORT/HARD)
  65. CORRECTION TO IPN/RXTE ERROR BOX FOR GRB001025
  66. GRB001007: Optical observations
  67. ASM Localization of GRB 001025
  68. GRB001007, Radio observations
  69. GRB 001018, Possible Radio Afterglow
  70. GRB001018, Gamma Ray Observations
  71. IPN TRIANGULATION OF GRB001019
  72. IPN TRIANGULATION OF GRB001018
  73. IPN TRIANGULATION OF GRB 001017
  74. V,R,I band observations of GRB000926
  75. HETE positions added to GCN
  76. GRB000926 - Amateur Optical Observations
  77. CONCAM null result on GRB001005
  78. IPN triangulation of GRB001005
  79. GRB000926: X-ray afterglow by BeppoSAX. Refined analysis
  80. GRB000926 - Optical observations
  81. GRB000926 - Optical observations
  82. GRB 000926, Optical Decay
  83. GRB000911: VLT infrared observation
  84. GRB 000926, Optical Observations
  85. GRB000926 K'-band Observation
  86. J and K band observations of GRB 000926
  87. GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
  88. CONCAM crude optical limits before and after GRB000926
  89. GRB 000926: Preliminary R-band Lightcurve
  90. Spectroscopic Redshift of GRB 000926
  91. GRB 000926: Optical candidate
  92. Optical candidate for GRB000926
  93. GRB 000911, BVRI field photometry
  94. GRB000911, Radio and Optical observations
  95. GRB000911: Optical observations
  96. GRB000830, BVRI field photometry
  97. GRB000210, Optical observations
  98. "Snapshot" afterglow IDs and GRB 000830
  99. GRB000730, Gamma Ray Observations
  100. GRB000812, Radio observations

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