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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"

37936 results found.

  1. INTEGRAL GRB 030331
  2. GRB 030324: Optical and NIR Observations
  3. GRB 030328, optical photometry
  4. GRB030329: R band light curve by MASTER
  5. GRB030329 - Light curve flattening
  6. GRB 030329: SARA Optical Observations
  7. GRB 030324, optical search
  8. GRB030329 - near contemporaneous optical limits from CONCAM
  9. GRB 030329, optical observations
  10. GRB 030329: Light curve observed during the change of its slope.
  11. GRB030329, BVRcIc field photometry
  12. GRB030329, SPM optical observations
  13. GRB 030329: Optical Decay
  14. Redshift of GRB 030329
  15. GRB030329: ROTSE network observes steepening of decay curve
  16. GRB 030329, optical photometry
  17. GRB 030329: Optical decay and synthesis
  18. GRB 030329: Radio Observations
  19. GRB 030329, optical spectroscopy
  20. GRB 030329: still bright
  21. GRB 030329: Optical pre-Imaging
  22. GRB 030329: visual observations
  23. GRB 030329: Upper limit from 5.6 hours before trigger
  24. GRB030328: R optical observation
  25. GRB 030323: Gemini South VRI obsevations.
  26. GRB030329: Optical observations
  27. GRB 030329, R-band observations, supplement
  28. GRB030329:optical observations by MASTER
  29. GRB 030329: optical observations
  30. GRB 030329, R-band observations
  31. GRB 030329: OT B and R photometry, decline rate
  32. GRB030329: Upper limits from recent and historical observations.
  33. GRB030329 (=H2652): A Long, Extremely Bright GRB Localized by the HETE WXM and SXC
  34. RXTE detection of GRB 030329 afterglow
  35. GRB 030329: Optical Afterglow Observations
  36. GRB 030329: precise position from Kyoto images
  37. GRB 030328 Optical Observations
  38. GRB 030328: Optical observations
  39. GRB 030328: optical observations
  40. GRB 030329: Optical afterglow fading
  41. GRB 030329 follow-up
  42. GRB 030329: Optical afterglow candidate
  43. GRB 030329: OT candidate
  44. GRB 030329: Optical afterglow candidate
  45. GRB 030328: OT photometry
  46. VLT spectra of GRB 030328
  47. GRB 030328, optical spectroscopy
  48. GRB 030328, optical observations
  49. GRB030328 (=H2650): A Long, Bright GRB Localized by the HETE WXM and SXC
  50. GRB 030328: Optical observations
  51. Re: GRB 030328: Finding chart
  52. GRB 030328: Finding chart
  53. GRB 030328: Optical afterglow candidate
  54. GRB030131, BVRcIc field photometry
  55. Possible GRB030323 localized by INTEGRAL
  56. IPN triangulation of GRB030325 (final analysis)
  57. IPN triangulation of GRB030326 (single small error box)
  58. GRB 030323: SARA Optical Observations
  59. IPN triangulation of GRB030325 (single small error box)
  60. GRB030324, optical observations
  61. IPN triangulation of GRB030325 (two small error boxes)
  62. GRB 030324: TAROT optical observations
  63. GRB 030324 (HETE #2641): Optical observations
  64. GRB030324, Optical Observations
  65. GRB030323: Upper limits from recent and historical observations.
  66. GRB030323 (=H2640): A Faint, Long GRB Localized by the HETE WXM and SXC
  67. GRB030324 (=H2641): A Long GRB Localized in Real Time by the HETE WXM
  68. GRB030324 (=H2641): A Long GRB Localized in Real Time by the HETE WXM
  69. VLT/FORS2 spectra of GRB 030323
  70. GRB030323, ROTSE-III detection of possible optical counterpart
  71. GRB030323, optical observations
  72. GRB030324, BVRcIc field photometry
  73. GRB030323, possible optical counterpart
  74. GRB030323, BVRcIc field calibration
  75. GRB 030324 optical observations
  76. GRB 030320: Optical Observations
  77. GRB 030324, optical observations
  78. IPN triangulation of GRB030320B (annulus)
  79. IPN triangulation of GRB030320 (small error box)
  80. IPN triangulation of GRB030320
  81. Possible GRB 030320 localized by INTEGRAL
  82. IPN upper limit to a GRB associated with SN2003L
  83. IPN triangulation of GRB030317 (annulus)
  84. IPN triangulation of GRB030307 (annulus)
  85. GRB 030227: Optical limit at RIKEN
  86. GRB 030226 Optical observations
  87. IPN triangulation of GRB030306 (single small error box - REVISED)
  88. GRB030226: Optical observations at Asiago
  89. IPN triangulation of GRB030306 (single small error box)
  90. IPN triangulation of GRB030306 (two small error boxes)
  91. IPN triangulation of GRB030306 (intense; annulus only so far)
  92. GRB 030226: Optical observations
  93. IPN triangulation of GRB030304 (annulus)
  94. GRB 030227: Optical observations
  95. GRB030226, BVRc observations
  96. Chandra detection of the X-ray afterglow of GRB 030226
  97. GRB 030226, further optical/NIR imaging
  98. GRB030227, optical observations
  99. GRB 030226: Ic Observations
  100. GRB030227: Kiso optical upper limit

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