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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"

27774 results found.

  1. RXTE detection of GRB 030329 afterglow
  2. Possible GRB030323 localized by INTEGRAL
  3. GRB030323: Detection on 2003/03/24
  4. VLT/FORS2 spectra of GRB 030323
  5. GRB030323, ROTSE-III detection of possible optical counterpart
  6. Possible GRB 030320 localized by INTEGRAL
  7. GRB030226: Analysis of Chandra data
  8. Chandra detection of the X-ray afterglow of GRB 030226
  9. GRB 030228, optical observations
  10. GRB030227 localized by INTEGRAL
  11. GRB030226 (=U10893): A Long GRB Localized by the HETE WXM and SXC
  12. GRB 030217: Optical Observations at 4, 5, and 6 Days
  13. GRB030115, WSRT radio observations - correction to GCN 1864
  14. GRB 030131: marginal optical detection
  15. GRB030115, WSRT radio observations
  16. A long GRB detected by INTEGRAL
  17. GRB 030115: Radio detection of IR candidate
  18. GRB 030115: IR observations with IRSF/SIRIUS
  19. GRB030115: R-band counterpart of IR candidate
  20. GRB030115: TAROT optical observations
  21. GRB 030115, optical candidate
  22. GRB 021112: Evidence for Another Dark Optical Afterglow
  23. GRB021219: a long GRB localized by INTEGRAL
  24. IPN detection of continued activity from SGR1806-20
  25. GRB 021211, optical observations
  26. GRB021211: Measurement of Early Time Afterglow
  27. IPN detection of renewed activity from SGR1806-20
  28. IPN detection of continued SGR1900+14 activity
  29. GRB021125 : A long GRB localized by INTEGRAL
  30. IPN detection of possible reactivation of SGR1900+14
  31. GRB 021113: Evidence for a Dark Optical Afterglow
  32. Detection of activity from SGR 1900+14 with the RXTE/PCA
  33. GRB 020813; likely host galaxy.
  34. GRB 021008, optical observations
  35. GRB 021004: optical spectroscopy on Oct 11
  36. GRB021004: optical observation
  37. GRB 021004: WC wind?
  38. GRB 021004: Optical observations, AUDE network
  39. GRB 021004: optical spectroscopy
  40. IRAM Millimeter detection of GRB 021004
  41. GRB 021004 radio search
  42. XRF 020903: optical observation at Kyoto
  43. GRB020322 : HST/STIS observations
  44. IPN detection of a burst from SGR1900+14
  45. XRF 020903, optical observations
  46. Confirming no variability for GRB02081
  47. GRB020813: Early Time Magnitude
  48. GRB 020813, radio detection
  49. GRB020812: optical observations
  50. GRB 020813 multiband optical observations
  51. HST Imaging of the Host of GRB 011121
  52. GRB 020410: Discovery of Probable OT by HST
  53. GRB 020625, optical observations
  54. GRB/XRF 020427, detection of an underlying system with the VLT
  55. Gemini IR Detection of AXP 1E 2259+586 Post-Burst
  56. AXP 1E2259+586: quasi-simultaneous optical observation
  57. AXP 1E2259+586 optical observations
  58. GRB 020531, simultaneous optical observations
  59. GRB020531: Detection of Candidate Host Galaxy
  60. GRB020531: Upper Limit for Detection of Two TAROT Sources
  61. IPN detection of possible bursts from SGR1806-20
  62. HETE Observations of GX354-0 (= MXB1728-34, so-called "Slow
  63. HST detection of the likely host galaxy of GRB 020124
  64. The end of BSAX GRB activities
  65. GRB 020124: Optical observations
  66. GRB020410: BeppoSAX NFI observations refined analysis
  67. Mars Odyssey joins the IPN
  68. GRB020405: predicted break
  69. GRB 020409, No Optical Detection to R = 22
  70. GRB 020331 Kyoto observation on March 31
  71. GRB 020409
  72. GRB 020409, No Optical Detection to R = 20
  73. X-ray afterglow of GRB020321
  74. ASM GRB candidate 020406 refined error box
  75. GRB020331: Optical Observations of Afterglow Candidate
  76. GRB020406(?), optical observations
  77. GRB 020405, U-band observations
  78. GRB011212: Optical Observations
  79. GRB 020322: Optical Observations
  80. GRB020127: Proposed Host Galaxy Detection and Identification of Afterglow
  81. GRB 020322 optical observation
  82. GRB020322, optical observations
  83. GRB020321: BeppoSAX/NFI Observations
  84. GRB020321: a faint BeppoSAX detection
  85. GRB020317 (=H1959): Localization by HETE of a Low Fluence GRB
  86. GRB020317, optical observations
  87. GRB 011121: HST Observations reveal an intermediate-time multicolor
  88. XRF/GRB 011030: Detection of the Probable Host Galaxy
  89. GRB020305 (=H1939): Localization of a GRB by HETE
  90. IPN detection and localization of Cygnus X-1 flares
  91. GRB020127: Further VLA Observations of Possible Counterparts
  92. IPN detection of further SGR1900+14 activity
  93. IPN/HETE Detection of Bursts from SGR1900+14
  94. GRB020127: Palomar and VLA Observations of Possible Counterparts
  95. GRB020127: Comparison of Chandra Epochs and Identification of Possible Counterparts
  96. Type Ib/c SN2002ap (SN/GRB?)
  97. Type Ib/c SN2002ap (SN/GRB?) Radio Observations
  98. IPN detection of further activity from SGR1806-20
  99. GRB020127(=H1902): Localization of a Double-Peaked GRB by HETE
  100. GRB020124(=H1896): Localization of a Long GRB by HETE

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