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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"

3996 results found.

  1. GRB030329: Optical observations
  2. GRB 030329: Correction to GCN 2056
  3. GRB 030329: optical observations
  4. GRB 030328, optical photometry
  5. GRB030329: R band light curve by MASTER
  6. GRB030329 - near contemporaneous optical limits from CONCAM
  7. GRB 030329: Optical pre-Imaging
  8. GRB 030329: visual observations
  9. GRB 030329: OT B and R photometry, decline rate
  10. GRB030329 (=H2652): A Long, Extremely Bright GRB Localized by the HETE WXM and SXC
  11. RXTE detection of GRB 030329 afterglow
  12. GRB 030329: Optical Afterglow Observations
  13. GRB 030328 Optical Observations
  14. GRB030328: Decay index
  15. GRB 030329: OT candidate
  16. GRB030328: optical spectroscopy at TNG
  17. GRB030328: optical photometry at the TNG
  18. GRB030328 (=H2650): A Long, Bright GRB Localized by the HETE WXM and SXC
  19. IPN triangulation of GRB030326 (single small error box)
  20. GRB 030323: SARA Optical Observations
  21. IPN triangulation of GRB030325 (two small error boxes)
  22. GRB030323: V, R, I photometry
  23. GRB 030227: fading of candidate optical afterglow 'S1-A'
  24. GRB 030227, possible optical counterpart of XMM-Newton source
  25. GRB030227 - faint tentative OT candidate
  26. XMM-Newton observation of GRB030227
  27. GRB 030227: Kyoto optical observation
  28. GRB030227: refined INTEGRAL position
  29. GRB 030131: marginal optical detection
  30. Probable GRB030112 seen by SPI ACS
  31. VLT spectroscopy of the probable host of GRB 021211
  32. IPN triangulation of GRB021219
  33. IPN detection of continued activity from SGR1806-20
  34. IPN triangulation of GRB021211B (two large error boxes)
  35. GRB021211 (=H2493): A Bright, Long GRB Localized by HETE-2 in Near-Real Time
  36. IPN detection of renewed activity from SGR1806-20
  37. GRB 021201: BOOTES simultaneous optical observations
  38. GRB021004, late time optical observations
  39. IPN detection of continued SGR1900+14 activity
  40. IPN confirmation of the reactivation of SGR1900+14
  41. IPN detection of possible reactivation of SGR1900+14
  42. GRB 021113: Evidence for a Dark Optical Afterglow
  43. GRB 021112: RAPTOR Observations
  44. GRB021112 (=H2448): A Long GRB Localized by HETE
  45. IPN triangulation of bursts from SGR1900+14, November 1-2, 2002
  46. SGR1900+14 activity, November 2-4, 2002
  47. Detection of activity from SGR 1900+14 with the RXTE/PCA
  48. IPN triangulation of a burst from SGR1900+14 on November 01, 2002
  49. IPN triangulation of a burst from SGR1900+14 on October 29 2002
  50. IPN triangulation of GRB021020 (smaller error box)
  51. IPN triangulation of GRB021020
  52. GRB021016(=H2397): A Long GRB Localized by HETE
  53. IPN triangulation of GRB021013 (two small error boxes)
  54. GRB021004: BVRc photometry
  55. GRB 021004: Optical Observations
  56. IPN triangulation of GRB020914
  57. IPN detection of a burst from SGR1900+14
  58. IPN triangulation of GRB020715 (=GRB150702)
  59. IPN triangulation of GRB150702
  60. IPN triangulation of GRB020708
  61. IPN triangulation of GRB020708
  62. Gemini IR Detection of AXP 1E 2259+586 Post-Burst
  63. SGR-like X-ray Bursts from AXP 1E 2259+586: follow-up
  64. AXP 1E2259+586: quasi-simultaneous optical observation
  65. AXP 1E2259+586 optical observations
  66. SGR-like Bursts from the AXP 1E 2259+586
  67. GRB 020604, optical observations
  68. GRB020604, optical observations
  69. IPN triangulation of GRB020604
  70. GRB020531: Optical observations
  71. GRB020525, optical observations
  72. IPN detection of possible bursts from SGR1806-20
  73. IPN triangulation of GRB020525
  74. XRF 020427: Sudden Ionospheric Disturbance (SID)
  75. Mars Odyssey joins the IPN
  76. Short RXTE/ASM transient 020406; may be a GRB
  77. XRF/GRB 011030: Detection of the Probable Host Galaxy
  78. IPN detection and localization of Cygnus X-1 flares
  79. RXTE Observations of SGR 1900+14
  80. SGR1900+14 activity
  81. IPN/HETE Detection of Bursts from SGR1900+14
  82. IPN Upper Limits to a GRB Associated With SN2002ap
  83. IPN detection of further activity from SGR1806-20
  84. Optical observation of SGR 1806-20 at the 6-m SAO telescope
  85. GRB010923 as seen by BeppoSAX GRBM
  86. HETE Trigger #1760 (GRB 010920B?): new optical source = asteroid
  87. Probable SGR or Short Duration GRB Detected by HETE
  88. Dramatic Increase in the Rate of X-ray Bursts Reported by HETE
  89. GRB 010629 Optical Observations
  90. GRB010629: A Burst Localized by HETE
  91. Possible burst from SGR1806-20
  92. IPN detection of SGR1900+14
  93. X-ray precursors to the large flare from SGR 1900+14
  94. SGR 1900+14: No evidence of extended X-ray emission
  95. SGR 1900+14 : RXTE observations
  96. BeppoSAX/NFI Follow-up Observation of SGR 1900+14
  97. SGR1900+14
  98. SGR 1900+14: Correction to GCN 1049
  99. Millimeter observation of SGR 1900+14
  100. SGR 1900+14: Detection of extended X-ray emission

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