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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').
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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.

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subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

25031 results found.

  1. Further Optical Observations of GRB 010324
  2. GRB010222, CXO X-ray observations
  3. GRB010324, optical observations
  4. GRB010326B: Localization by HETE (2nd GRB for this date)
  5. GRB 010326 optical observations
  6. GRB010326: Refined Localization by HETE
  7. GRB010326: Localization by HETE
  8. Optical Observations of GRB 010324
  9. GRB010222, late-time optical observation
  10. Support extension to the BeppoSAX mission
  11. GRB 010222 - HEGRA GeV/TeV Observations
  12. GRB010222: Chandra X-ray Observatory Observation
  13. GRB010222: Sub-millimeter vanishing act
  14. GRB010222 - Optical observation
  15. GRB 010222, Optical Observations
  16. GRB010222 - Optical observation
  17. GRB 010222: High-Resolution Keck Spectroscopy
  18. GRB 010214, I-band data
  19. GRB 010222
  20. GRB010222 further R-band photometry
  21. GRB010222: R-band data
  22. GRB 010222: Keck Spectroscopy
  23. GRB010214, field photometry
  24. GRB010222, field photometry
  25. GRB010222 further R-band photometry
  26. GRB010222, possible increase of optical decay slope
  27. GRB 010222 Kyoto optical observation
  28. GRB010222 R-BAND OBSERVATION
  29. GRB010214 follow-up from Hanle
  30. GRB 010222: Near-IR Observations
  31. GRB 010222: Optical Observations
  32. GRB010222: Optical decay slope
  33. GRB 010214, Optical Observations
  34. GRB010222, radio observations
  35. GRB010222, optical observations
  36. GRB010222: BeppoSAX/NFI Observations
  37. GRB010214B,Gamma Ray Observations
  38. GRB 010220, simultaneous optical observations
  39. GRB010220: BeppoSAX WFC and GRBM preliminary data
  40. GRB010214, candidate optical afterglow
  41. GRB010214, optical observations
  42. GRB010214: BeppoSAX WFC and GRBM preliminary data
  43. GRB 010214: X-Ray afterglow
  44. GRB 010214 optical observation
  45. GRB010213, Radio Observations
  46. J-Band Observation of GRB 010214.
  47. GRB010213, Near-IR observations
  48. Possible InfraRed Transient of GRB 010214.
  49. GRB 010214, optical observations
  50. GRB010213 detected by HETE
  51. IPN Status Report
  52. HETE Status
  53. IPN/RXTE TRIANGULATION OF GRB010126
  54. GRB010126 Optical Observations
  55. IPN TRIANGULATION OF GRB010126
  56. Optical Observations of GRB 001018 at Keck
  57. IPN TRIANGULATION OF GRB010119 (SHORT/HARD)
  58. Optical observations of GRB 001018 with JCAM
  59. IPN TRIANGULATION OF GRB010115
  60. IPN TRIANGULATION OF GRB010109
  61. IPN TRIANGULATION OF GRB010109
  62. IPN triangulation of GRB010104
  63. IPN triangulation of GRB010103
  64. H band observation of GRB 001212
  65. IPN triangulation of GRB001219
  66. GRB 001212 Optical Observation
  67. GRB 001212 Optical Observation
  68. GRB 001212 possible OA in 2MASS
  69. IPN triangulation of GRB001212
  70. Confirmation of IPN position for GRB001204
  71. IPN triangulation of GRB001204 (short/hard)
  72. GRB001120, optical observations
  73. WSRT 4.8 GHz observations of GRB001109
  74. IPN triangulation of GRB001120
  75. GRB 001109: deep JHK upper limits
  76. GRB 001109 X-ray afterglow with BeppoSAX
  77. CORRECTION to XMM-Newton observation of GRB001025
  78. GRB001109, Radio observations
  79. GRB001105 BVRI field photometry correction
  80. GRB001105, BVRI field photometry
  81. IPN TRIANGULATION OF GRB001105
  82. GRB 001025B, Optical obervations
  83. GRB 991208: HST Imaging of the Host Galaxy
  84. GRB 001025B, I-band observations
  85. XMM-Newton observation of GRB001025
  86. IPN TRIANGULATION OF GRB001025B (SHORT/HARD)
  87. CORRECTION TO IPN/RXTE ERROR BOX FOR GRB001025
  88. GRB001007: Optical observations
  89. ASM Localization of GRB 001025
  90. GRB001007, Radio observations
  91. GRB 001018, Possible Radio Afterglow
  92. GRB001018, Gamma Ray Observations
  93. IPN TRIANGULATION OF GRB001019
  94. IPN TRIANGULATION OF GRB001018
  95. IPN TRIANGULATION OF GRB 001017
  96. V,R,I band observations of GRB000926
  97. HETE positions added to GCN
  98. GRB000926 - Amateur Optical Observations
  99. CONCAM null result on GRB001005
  100. IPN triangulation of GRB001005

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