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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"

36148 results found.

  1. GRB 030329: further optical observations
  2. GRB030329 - OT brightens
  3. GRB 030329: OT observations at Kanazawa
  4. GRB030329 15 GHz radio observation
  5. GRB 030329 RBO V Optical Observations
  6. GRB 030329, optical photometry
  7. GRB030329: Near Infrared Observations
  8. 030331 NOT A GRB
  9. INTEGRAL GRB 030331
  10. GRB 030324: Optical and NIR Observations
  11. GRB 030328, optical photometry
  12. GRB030329: R band light curve by MASTER
  13. GRB030329 - Light curve flattening
  14. GRB 030329: SARA Optical Observations
  15. GRB 030324, optical search
  16. GRB030329 - near contemporaneous optical limits from CONCAM
  17. GRB 030329, optical observations
  18. GRB 030329: Light curve observed during the change of its slope.
  19. GRB030329, BVRcIc field photometry
  20. GRB030329, SPM optical observations
  21. GRB 030329: Optical Decay
  22. Redshift of GRB 030329
  23. GRB030329: ROTSE network observes steepening of decay curve
  24. GRB 030329, optical photometry
  25. GRB 030329: Optical decay and synthesis
  26. GRB 030329: Radio Observations
  27. GRB 030329, optical spectroscopy
  28. GRB 030329: still bright
  29. GRB 030329: Optical pre-Imaging
  30. GRB 030329: visual observations
  31. GRB 030329: Upper limit from 5.6 hours before trigger
  32. GRB030328: R optical observation
  33. GRB 030323: Gemini South VRI obsevations.
  34. GRB030329: Optical observations
  35. GRB 030329, R-band observations, supplement
  36. GRB030329:optical observations by MASTER
  37. GRB 030329: optical observations
  38. GRB 030329, R-band observations
  39. GRB 030329: OT B and R photometry, decline rate
  40. GRB030329: Upper limits from recent and historical observations.
  41. GRB030329 (=H2652): A Long, Extremely Bright GRB Localized by the HETE WXM and SXC
  42. RXTE detection of GRB 030329 afterglow
  43. GRB 030329: Optical Afterglow Observations
  44. GRB 030329: precise position from Kyoto images
  45. GRB 030328 Optical Observations
  46. GRB 030328: Optical observations
  47. GRB 030328: optical observations
  48. GRB 030329: Optical afterglow fading
  49. GRB 030329 follow-up
  50. GRB 030329: Optical afterglow candidate
  51. GRB 030329: OT candidate
  52. GRB 030329: Optical afterglow candidate
  53. GRB 030328: OT photometry
  54. VLT spectra of GRB 030328
  55. GRB 030328, optical spectroscopy
  56. GRB 030328, optical observations
  57. GRB030328 (=H2650): A Long, Bright GRB Localized by the HETE WXM and SXC
  58. GRB 030328: Optical observations
  59. Re: GRB 030328: Finding chart
  60. GRB 030328: Finding chart
  61. GRB 030328: Optical afterglow candidate
  62. GRB030131, BVRcIc field photometry
  63. Possible GRB030323 localized by INTEGRAL
  64. IPN triangulation of GRB030325 (final analysis)
  65. IPN triangulation of GRB030326 (single small error box)
  66. GRB 030323: SARA Optical Observations
  67. IPN triangulation of GRB030325 (single small error box)
  68. GRB030324, optical observations
  69. IPN triangulation of GRB030325 (two small error boxes)
  70. GRB 030324: TAROT optical observations
  71. GRB 030324 (HETE #2641): Optical observations
  72. GRB030324, Optical Observations
  73. GRB030323: Upper limits from recent and historical observations.
  74. GRB030323 (=H2640): A Faint, Long GRB Localized by the HETE WXM and SXC
  75. GRB030324 (=H2641): A Long GRB Localized in Real Time by the HETE WXM
  76. GRB030324 (=H2641): A Long GRB Localized in Real Time by the HETE WXM
  77. VLT/FORS2 spectra of GRB 030323
  78. GRB030323, ROTSE-III detection of possible optical counterpart
  79. GRB030323, optical observations
  80. GRB030324, BVRcIc field photometry
  81. GRB030323, possible optical counterpart
  82. GRB030323, BVRcIc field calibration
  83. GRB 030324 optical observations
  84. GRB 030320: Optical Observations
  85. GRB 030324, optical observations
  86. IPN triangulation of GRB030320B (annulus)
  87. IPN triangulation of GRB030320 (small error box)
  88. IPN triangulation of GRB030320
  89. Possible GRB 030320 localized by INTEGRAL
  90. IPN upper limit to a GRB associated with SN2003L
  91. IPN triangulation of GRB030317 (annulus)
  92. IPN triangulation of GRB030307 (annulus)
  93. GRB 030227: Optical limit at RIKEN
  94. GRB 030226 Optical observations
  95. IPN triangulation of GRB030306 (single small error box - REVISED)
  96. GRB030226: Optical observations at Asiago
  97. IPN triangulation of GRB030306 (single small error box)
  98. IPN triangulation of GRB030306 (two small error boxes)
  99. IPN triangulation of GRB030306 (intense; annulus only so far)
  100. GRB 030226: Optical observations

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