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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"

26295 results found.

  1. GRB 030329, optical photometry
  2. GRB030329 optical observations
  3. GRB 030329: Optical pre-Imaging
  4. GRB 030329: visual observations
  5. GRB030328: R optical observation
  6. GRB030328: X-ray Afterglow Observed with Chandra
  7. GRB030329: Optical observations
  8. GRB030329 optical observations
  9. GRB030329:optical observations by MASTER
  10. GRB 030329: optical observations
  11. GRB 030329, R-band observations
  12. GRB030329: Upper limits from recent and historical observations.
  13. GRB030329 (=H2652): A Long, Extremely Bright GRB Localized by the HETE WXM and SXC
  14. RXTE detection of GRB 030329 afterglow
  15. GRB 030329: Optical Afterglow Observations
  16. GRB 030328 Optical Observations
  17. GRB030328: Decay index
  18. GRB 030328: Optical observations
  19. GRB 030328: optical observations
  20. GRB 030329 follow-up
  21. GRB 030329: OT candidate
  22. GRB030328: optical spectroscopy at TNG
  23. GRB030328: optical photometry at the TNG
  24. VLT spectra of GRB 030328
  25. GRB 030328, optical observations
  26. GRB030328 (=H2650): A Long, Bright GRB Localized by the HETE WXM and SXC
  27. GRB030323 optical observations
  28. GRB030131, BVRcIc field photometry
  29. Possible GRB030323 localized by INTEGRAL
  30. GRB030323: Detection on 2003/03/24
  31. IPN triangulation of GRB030326 (single small error box)
  32. GRB 030323: SARA Optical Observations
  33. GRB030324, optical observations
  34. GRB030324, optical observations
  35. IPN triangulation of GRB030325 (two small error boxes)
  36. GRB030323: V, R, I photometry
  37. GRB030323: Upper limits from recent and historical observations.
  38. GRB030323 (=H2640): A Faint, Long GRB Localized by the HETE WXM and SXC
  39. GRB030324 (=H2641): A Long GRB Localized in Real Time by the HETE WXM
  40. GRB030324 (=H2641): A Long GRB Localized in Real Time by the HETE WXM
  41. GRB030323, ROTSE-III detection of possible optical counterpart
  42. GRB030323, optical observations
  43. GRB030323, possible optical counterpart
  44. GRB 030320: Optical Observations
  45. IPN triangulation of GRB030320B (annulus)
  46. IPN triangulation of GRB030320 (small error box)
  47. Possible GRB 030320 localized by INTEGRAL
  48. GRB030226, addendum to GCN 1892
  49. IPN upper limit to a GRB associated with SN2003L
  50. IPN triangulation of GRB030317 (annulus)
  51. IPN triangulation of GRB030307 (annulus)
  52. GRB 030227: Optical limit at RIKEN
  53. IPN triangulation of GRB030306 (single small error box - REVISED)
  54. GRB030226: Optical observations at Asiago
  55. IPN triangulation of GRB030306 (intense; annulus only so far)
  56. GRB 030226: Optical observations
  57. GRB030226: Analysis of Chandra data
  58. IPN triangulation of GRB030304 (annulus)
  59. GRB 030227: Optical observations
  60. GRB030226, BVRc observations
  61. Chandra detection of the X-ray afterglow of GRB 030226
  62. GRB 030226, further optical/NIR imaging
  63. GRB030227: Kiso optical upper limit
  64. IPN triangulation of GRB030301 (annulus)
  65. IPN triangulation of GRB030228 (annulus)
  66. GRB030226, BVRcIc field calibration
  67. GRB 030227 optical afterglow
  68. GRB 030226: Steep Decline
  69. GRB 030227: Confirmed Optical Afterglow (S1-A)
  70. GRB 030226: Optical observations
  71. GRB 030227: fading of candidate optical afterglow 'S1-A'
  72. GRB 20030226: Upper limits from recent and historical observations
  73. GRB 030227, possible optical counterpart of XMM-Newton source
  74. GRB 030226, optical observations
  75. GRB030227: Kiso optical observations
  76. GRB 030226, optical light curve
  77. GRB030227 localized by INTEGRAL
  78. Possible break in the GRB 030226 light curve
  79. IPN triangulation of GRB030225 (annulus)
  80. GRB 030226: Confirmed decay index
  81. GRB030226: ESI spectroscopy
  82. GRB030226 (=U10893): A Long GRB Localized by the HETE WXM and SXC
  83. GRB 030226: Optical afterglow
  84. GRB030226: Candidate optical afterglow
  85. IPN triangulation of GRB030223 (annulus)
  86. IPN triangulation of GRB030220 (annulus)
  87. GRB: Non-Referencing of GCN Circulars.
  88. IPN triangulation of GRB030218 (annulus)
  89. GRB030217: optical observations
  90. IPN triangulation of GRB030217 (small error box)
  91. IPN triangulation of GRB030215C (annulus)
  92. IPN triangulation of GRB030217 (annulus)
  93. IPN triangulation of GRB030216 (annulus)
  94. IPN triangulation of GRB030215A and GRB030215B (annuli)
  95. GRB 030131: marginal optical detection
  96. IPN triangulation of GRB030208 (annulus)
  97. GRB020819: Kiso R and I band observations
  98. GRB030131: Candidate Optical Afterglow
  99. IPN triangulation of GRB030204 (small error box)
  100. IPN triangulation of GRB030202 (annulus)

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