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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"

25904 results found.

  1. GRB030328: X-ray Afterglow Observed with Chandra
  2. GRB 030323: Gemini South VRI obsevations.
  3. GRB 030329: optical observations
  4. GRB 030329, R-band observations
  5. RXTE detection of GRB 030329 afterglow
  6. GRB 030329: Optical Afterglow Observations
  7. GRB 030329: precise position from Kyoto images
  8. GRB 030328 Optical Observations
  9. GRB030328: Decay index
  10. GRB 030329: Optical afterglow fading
  11. GRB 030329 follow-up
  12. GRB 030329: Optical afterglow candidate
  13. GRB 030329: Optical afterglow candidate
  14. GRB030328: optical spectroscopy at TNG
  15. GRB030328: optical photometry at the TNG
  16. VLT spectra of GRB 030328
  17. GRB 030328, optical spectroscopy
  18. GRB 030328, optical observations
  19. GRB 030328: Optical observations
  20. GRB 030328: Finding chart
  21. GRB 030328: Optical afterglow candidate
  22. GRB030131, BVRcIc field photometry
  23. GRB 030323: SARA Optical Observations
  24. GRB030324, optical observations
  25. GRB030323: V, R, I photometry
  26. GRB 030324 (HETE #2641): Optical observations
  27. VLT/FORS2 spectra of GRB 030323
  28. GRB 030226 Optical observations
  29. Chandra detection of the X-ray afterglow of GRB 030226
  30. GRB 030226, further optical/NIR imaging
  31. GRB 030226: Ic Observations
  32. GRB030227: Kiso optical upper limit
  33. GRB 030227 optical afterglow
  34. GRB 030226: Steep Decline
  35. GRB 030227: Confirmed Optical Afterglow (S1-A)
  36. GRB 030226: R band polarimetric observations
  37. GRB 030227: fading of candidate optical afterglow 'S1-A'
  38. GRB030227:Optical observations
  39. GRB 030227, possible optical counterpart of XMM-Newton source
  40. GRB 030226, optical observations
  41. GRB 030226, optical light curve
  42. GRB 030226 spectroscopy
  43. Possible break in the GRB 030226 light curve
  44. GRB 030226 : Predicted light curve
  45. GRB030226: optical observation
  46. GRB 030226: Confirmed decay index
  47. GRB030226: ESI spectroscopy
  48. Two absorption systems in GRB 030226
  49. GRB 030226, optical observations
  50. GRB030226: optical observations and refined redshift
  51. GRB030226: Optical decay index
  52. GRB 030226 Optical Spectra and R,I,z' Imaging
  53. GRB 030226: Optical afterglow
  54. GRB030226: Candidate optical afterglow
  55. GRB 030217: Optical Observations at 4, 5, and 6 Days
  56. GRB030115, WSRT radio observations - correction to GCN 1864
  57. GRB030115, WSRT radio observations
  58. GRB030204 field photometry
  59. GRB020819: Kiso R and I band observations
  60. GRB030131: Candidate Optical Afterglow
  61. GRB 030131, optical observations
  62. GRB030131: Optical limits for corrected position
  63. GRB 030131: afterglow candidate
  64. GRB 020819: afterglow candidate
  65. GRB030115: 1.2 mm upper limits with MAMBO @ IRAM 30m
  66. GRB030115 submm upper limit
  67. GRB 030115: Further IR observations with IRSF/SIRIUS
  68. GRB 030115: Radio detection of IR candidate
  69. GRB 030115: IR observations with IRSF/SIRIUS
  70. GRB030115: R-band counterpart of IR candidate
  71. GRB030115, afterglow candidate
  72. GRB 021211: R-band observations at late-time
  73. GRB 021211: VLT spectrum
  74. GRB 021211: Probable Host and Underlying Supernova
  75. GRB021211, radio observations
  76. GRB 021112: Evidence for Another Dark Optical Afterglow
  77. VLT spectra of GRB 021211 revisited
  78. GRB021211: APO optical observations
  79. GRB 021211, optical observations
  80. GRB 021211: CTIO observations
  81. GRB021211: Measurement of Early Time Afterglow
  82. VLT spectrum of GRB 021211
  83. GRB 021211: early break in light curve
  84. GRB021211: Optical observations in CrAO
  85. GRB 021211, IR observations
  86. GRB 021211, optical observations
  87. GRB021211: Kiso Observations
  88. GRB021204: Kiso Observations
  89. GRB021211: Optical observations
  90. GRB 021211, R- and I-band observations
  91. GRB021211 (=H2493): A Bright, Long GRB Localized by HETE-2 in Near-Real Time
  92. HETE 2493: Optical observations
  93. HETE 2493: Optical observations
  94. GRB021201, BVRcIc field photometry
  95. GRB 021112: Afterglow or Variable Star?
  96. GRB 021113: Evidence for a Dark Optical Afterglow
  97. GRB021112, BVRI field photometry
  98. GRB 021113: Optical observations
  99. GRB021004: Near infrared spectroscopy
  100. GRB021104: optical observations

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