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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"

26038 results found.

  1. GRB030329: further optical photometry and evidence for a light curve discontinuity
  2. GRB 030329: fitting parameters and re-brightening
  3. GRB 030329: KAIT optical photometry
  4. GRB030329 Further RBO Optical Observations
  5. GRB 030329: SARA Optical Observations
  6. AAVSO V & R observations of GRB030329
  7. GRB 030329: beginning of the new fading phase in optical band
  8. GRB 030329, optical spectroscopy
  9. GRB 030329: fading X-ray afterglow with RXTE
  10. GRB 030329: optical photometry
  11. GRB 030329, R-band observations
  12. GRB 030329, R-band light curve
  13. GRB 030329: further optical observations
  14. GRB 030329: OT observations at Kanazawa
  15. GRB 030329 RBO V Optical Observations
  16. GRB 030329, optical photometry
  17. GRB030329: Near Infrared Observations
  18. GRB 030328, optical photometry
  19. GRB 030329: SARA Optical Observations
  20. GRB 030329, optical observations
  21. GRB030328: X-ray Fading and Spectrum Measured with Chandra
  22. GRB 030329: Light curve observed during the change of its slope.
  23. GRB030329, SPM optical observations
  24. GRB 030329: Optical Decay
  25. Redshift of GRB 030329
  26. GRB 030329, optical photometry
  27. GRB 030329: Optical decay and synthesis
  28. GRB030329: optical spectroscopy with the TNG
  29. GRB 030329: Radio Observations
  30. GRB 030329, optical spectroscopy
  31. GRB 030329: still bright
  32. GRB 030329: Optical pre-Imaging
  33. GRB 030329: visual observations
  34. GRB030328: R optical observation
  35. GRB030328: X-ray Afterglow Observed with Chandra
  36. GRB 030323: Gemini South VRI obsevations.
  37. GRB 030329: optical observations
  38. GRB 030329, R-band observations
  39. RXTE detection of GRB 030329 afterglow
  40. GRB 030329: Optical Afterglow Observations
  41. GRB 030329: precise position from Kyoto images
  42. GRB 030328 Optical Observations
  43. GRB030328: Decay index
  44. GRB 030329: Optical afterglow fading
  45. GRB 030329 follow-up
  46. GRB 030329: Optical afterglow candidate
  47. GRB 030329: Optical afterglow candidate
  48. GRB030328: optical spectroscopy at TNG
  49. GRB030328: optical photometry at the TNG
  50. VLT spectra of GRB 030328
  51. GRB 030328, optical spectroscopy
  52. GRB 030328, optical observations
  53. GRB 030328: Optical observations
  54. GRB 030328: Finding chart
  55. GRB 030328: Optical afterglow candidate
  56. GRB030131, BVRcIc field photometry
  57. GRB 030323: SARA Optical Observations
  58. GRB030324, optical observations
  59. GRB030323: V, R, I photometry
  60. GRB 030324 (HETE #2641): Optical observations
  61. VLT/FORS2 spectra of GRB 030323
  62. GRB 030226 Optical observations
  63. Chandra detection of the X-ray afterglow of GRB 030226
  64. GRB 030226, further optical/NIR imaging
  65. GRB 030226: Ic Observations
  66. GRB030227: Kiso optical upper limit
  67. GRB 030227 optical afterglow
  68. GRB 030226: Steep Decline
  69. GRB 030227: Confirmed Optical Afterglow (S1-A)
  70. GRB 030226: R band polarimetric observations
  71. GRB 030227: fading of candidate optical afterglow 'S1-A'
  72. GRB030227:Optical observations
  73. GRB 030227, possible optical counterpart of XMM-Newton source
  74. GRB 030226, optical observations
  75. GRB 030226, optical light curve
  76. GRB 030226 spectroscopy
  77. Possible break in the GRB 030226 light curve
  78. GRB 030226 : Predicted light curve
  79. GRB030226: optical observation
  80. GRB 030226: Confirmed decay index
  81. GRB030226: ESI spectroscopy
  82. Two absorption systems in GRB 030226
  83. GRB 030226, optical observations
  84. GRB030226: optical observations and refined redshift
  85. GRB030226: Optical decay index
  86. GRB 030226 Optical Spectra and R,I,z' Imaging
  87. GRB 030226: Optical afterglow
  88. GRB030226: Candidate optical afterglow
  89. GRB 030217: Optical Observations at 4, 5, and 6 Days
  90. GRB030115, WSRT radio observations - correction to GCN 1864
  91. GRB030115, WSRT radio observations
  92. GRB030204 field photometry
  93. GRB020819: Kiso R and I band observations
  94. GRB030131: Candidate Optical Afterglow
  95. GRB 030131, optical observations
  96. GRB030131: Optical limits for corrected position
  97. GRB 030131: afterglow candidate
  98. GRB 020819: afterglow candidate
  99. GRB030115: 1.2 mm upper limits with MAMBO @ IRAM 30m
  100. GRB030115 submm upper limit

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