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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"

41689 results found.

  1. GRB 030329: visual observations
  2. GRB 030329: Upper limit from 5.6 hours before trigger
  3. GRB030328: R optical observation
  4. GRB030328: X-ray Afterglow Observed with Chandra
  5. GRB 030323: Gemini South VRI obsevations.
  6. GRB030329: Optical observations
  7. GRB030329 optical observations
  8. GRB030329:optical observations by MASTER
  9. GRB 030329: optical observations
  10. GRB 030329, R-band observations
  11. GRB 030329: OT B and R photometry, decline rate
  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 030329: precise position from Kyoto images
  17. GRB 030328 Optical Observations
  18. GRB030328: Decay index
  19. GRB 030328: Optical observations
  20. GRB 030328: optical observations
  21. GRB 030329: Optical afterglow fading
  22. GRB 030329: Optical afterglow candidate
  23. GRB 030329: OT candidate
  24. GRB 030329: Optical afterglow candidate
  25. GRB 030328: OT photometry
  26. GRB030328: optical spectroscopy at TNG
  27. GRB030328: optical photometry at the TNG
  28. VLT spectra of GRB 030328
  29. GRB 030328, optical spectroscopy
  30. GRB 030328, optical observations
  31. GRB030328 (=H2650): A Long, Bright GRB Localized by the HETE WXM and SXC
  32. GRB 030328: Optical observations
  33. GRB 030328: Finding chart
  34. GRB 030328: Optical afterglow candidate
  35. GRB030323 optical observations
  36. GRB030131, BVRcIc field photometry
  37. IPN triangulation of GRB030325 (final analysis)
  38. GRB030323: Detection on 2003/03/24
  39. GRB 030323: SARA Optical Observations
  40. IPN triangulation of GRB030325 (single small error box)
  41. GRB030324, optical observations
  42. GRB030324, optical observations
  43. GRB 030324: TAROT optical observations
  44. GRB030323: V, R, I photometry
  45. GRB 030324 (HETE #2641): Optical observations
  46. GRB030324, Optical Observations
  47. GRB030323: Upper limits from recent and historical observations.
  48. GRB030323 (=H2640): A Faint, Long GRB Localized by the HETE WXM and SXC
  49. GRB030324 (=H2641): A Long GRB Localized in Real Time by the HETE WXM
  50. GRB030324 (=H2641): A Long GRB Localized in Real Time by the HETE WXM
  51. VLT/FORS2 spectra of GRB 030323
  52. GRB030323, ROTSE-III detection of possible optical counterpart
  53. GRB030323, optical observations
  54. GRB030324, BVRcIc field photometry
  55. GRB030323, possible optical counterpart
  56. GRB030323, BVRcIc field calibration
  57. GRB 030324 optical observations
  58. GRB 030320: Optical Observations
  59. GRB 030324, optical observations
  60. IPN triangulation of GRB030320 (small error box)
  61. IPN triangulation of GRB030320
  62. GRB030226, addendum to GCN 1892
  63. IPN upper limit to a GRB associated with SN2003L
  64. GRB 030227: Optical limit at RIKEN
  65. GRB 030226 Optical observations
  66. IPN triangulation of GRB030306 (single small error box - REVISED)
  67. GRB030226: Optical observations at Asiago
  68. IPN triangulation of GRB030306 (single small error box)
  69. IPN triangulation of GRB030306 (two small error boxes)
  70. GRB 030226: Optical observations
  71. GRB030226: Analysis of Chandra data
  72. GRB 030227: Optical observations
  73. GRB030226, BVRc observations
  74. Chandra detection of the X-ray afterglow of GRB 030226
  75. GRB 030226, further optical/NIR imaging
  76. GRB030227, optical observations
  77. GRB 030226: Ic Observations
  78. GRB030227: Kiso optical upper limit
  79. GRB030227, BVRcIc field photometry
  80. GRB030226, BVRcIc field calibration
  81. GRB 030227 optical afterglow
  82. GRB 030228, optical observations
  83. GRB 030226: Steep Decline
  84. GRB 030227: Confirmed Optical Afterglow (S1-A)
  85. GRB 030226: R band polarimetric observations
  86. GRB 030226: Optical observations
  87. GRB 030227: fading of candidate optical afterglow 'S1-A'
  88. GRB030227:Optical observations
  89. GRB 20030226: Upper limits from recent and historical observations
  90. GRB 030227, possible optical counterpart of XMM-Newton source
  91. GRB030227 - faint tentative OT candidate
  92. GRB 030226, optical observations
  93. XMM-Newton observation of GRB030227
  94. GRB030227: Kiso optical observations
  95. GRB 030227: Kyoto optical observation
  96. GRB 030226, optical light curve
  97. GRB 030226 spectroscopy
  98. GRB030227: refined INTEGRAL position
  99. GRB030227 localized by INTEGRAL
  100. Possible break in the GRB 030226 light curve

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