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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"

5512 results found.

  1. GRB030323 optical observations
  2. GRB030323: Detection on 2003/03/24
  3. GRB 030323: SARA Optical Observations
  4. GRB030324 (=H2641): A Long GRB Localized in Real Time by the HETE WXM
  5. GRB 030227: Optical limit at RIKEN
  6. GRB 030226 Optical observations
  7. Chandra detection of the X-ray afterglow of GRB 030226
  8. GRB030227: Kiso optical upper limit
  9. 030302: NOT A GRB
  10. Possible break in the GRB 030226 light curve
  11. GRB030226 (=U10893): A Long GRB Localized by the HETE WXM and SXC
  12. GRB 030226 simultaneous optical observations
  13. GRB030226: Optical decay index
  14. GRB030131: Candidate Optical Afterglow
  15. GRB 030131: afterglow candidate
  16. GRB 030115, simultaneous observations by BOOTES-1
  17. GRB 030115: Radio Observations
  18. GRB030115 (=H2533): A Long GRB Localized by the HETE WXM and SXC
  19. GRB 030115, optical candidate
  20. Possible GRB030113 seen by SPI ACS
  21. Probable GRB030112B seen by SPI ACS
  22. Probable GRB030112 seen by SPI ACS
  23. Possible GRB030111 seen by SPI ACS
  24. Possible GRB030110b seen by SPI ACS
  25. Possible GRB 030110 seen by SPI ACS
  26. GRB021112 (=H2448): A Long GRB Localized by HETE
  27. GRB021104: possible optical afterglow
  28. GRB021016, optical observations
  29. GRB021004: Optical Observations
  30. GRB021004: BVRc photometry
  31. GRB021004 radio observation
  32. GRB 021004: Optical Decay
  33. GRB 021004: Optical Observations
  34. GRB 021004: Optical Observations
  35. GRB 021004, optical observations
  36. GRB 021004 radio search
  37. INTEGRAL GRBs added to GCN
  38. GRB 020812: early time optical observation at Ouda Station
  39. Early Time Limits for GRB020813
  40. GRB 020813 Afterglow Observations; Possible break
  41. GRB020812(=H2257): A Long Burst Localized by HETE in Near-Real Time
  42. GRB020801: Imaging of Suggested OT Counterpart at the Magellan
  43. IPN triangulation of GRB020714
  44. IPN triangulation of GRB020714
  45. GRB 020625, optical observations
  46. AXP 1E2259+586 optical observations
  47. IPN detection of possible bursts from SGR1806-20
  48. GRB 020409: No Evidence for an Optical Afterglow
  49. GRB020331 optical observations with RIMOTS
  50. Short RXTE/ASM transient 020406; may be a GRB
  51. Fading Optical Afterglow and Possible Host Galaxy of GRB 020405
  52. GRB011212: Optical Observations
  53. Bepposax GRB020322 The second springtime BSAX GRB
  54. GRB 020317 : KISO Optical Observations
  55. GRB020317 (=H1959): Localization by HETE of a Low Fluence GRB
  56. GRB020127 Optical Observations
  57. GRB011212: Optical observations at Gunma
  58. GRB 011211, Optical Observations
  59. GRB 011130: Optical Observations of Chandra Sources
  60. GRB 011130 I-band Observation
  61. GRB011130 (XRF011130) SDSS PT i-band observations
  62. XRF011130: Infrared Observations
  63. GRB011130, Radio Observations
  64. GRB010921, optical observation
  65. GRB010921 Optical Observations
  66. SGR1900+14 burst seen by HETE: BeppoSAX data
  67. GRB 010629 Optical Observations
  68. SGR1900+14: High Fluence Burst Localized by HETE
  69. GRB010326: Localization by HETE
  70. Sub-millimeter Excess/GRB 010222
  71. GRB010222: Sub-millimeter detection
  72. GRB010214 Optical Observation
  73. CORRECTION to XMM-Newton observation of GRB001025
  74. XMM-Newton observation of GRB001025
  75. CORRECTION TO IPN/RXTE ERROR BOX FOR GRB001025
  76. ASM Localization of GRB 001025
  77. GRB 001007, BVR-band observations
  78. GRB000926 - Amateur Optical Observations
  79. GRB000926 optical observations
  80. GRB 000615, near-infrared observations
  81. IPN triangulation of GRB000516
  82. GRB 000418, Optical Observation
  83. GRB000418, near-infrared observations
  84. GRB000301C: RXTE/ASM and IPN localizations
  85. SAX_WFC_GRB_NOTICE
  86. GRB 000201: TAROT optical observations
  87. IPN annulus for GRB000115
  88. Second RXTE Observation of GRB 000115
  89. GRB991216, UBVRIJHK field photometry
  90. GCN resumes full operations
  91. IPN error box for GRB991216
  92. GRB991216, optical observations
  93. IPN localization of GRB991105
  94. GRB 990806, Optical Observations
  95. GRB990704 radio and optical observations
  96. GRB 990704, optical observations
  97. Identification of a possible optical counterpart for GRB990704
  98. IPN error box for GRB990527
  99. GRB 990506 optical observations
  100. IPN localization for GRB990506

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