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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"

41193 results found.

  1. GRB 031203: z ~ 10 or Fragmented Dust in the Circumburst Environment?
  2. GRB 031203: Apparent Spectral Break
  3. GRB031203: Planned XMM-Newton observation II
  4. GRB 031203: IR REM Observations
  5. GRB031203: Optical Observations
  6. GRB 031203 XMM-Newton observation
  7. GRB 031203: Optical/IR SMARTS Observations
  8. GRB031203: Planned XMM-Newton observation
  9. IPN triangulation of GRB031127A and B (quasi-simultaneous; large error boxes)
  10. GRB 031203: A long GRB detected with INTEGRAL
  11. IPN triangulation of GRB031130 (large error box)
  12. GRB031111A, prompt optical observations
  13. GRB 031111B (= H2925) : Kyoto Optical Observation
  14. IPN/HETE localization of GRB031109 (=H2917; large error box)
  15. IPN detection of activity from SGR1806-20
  16. GRB 031111, Radio observations
  17. GRB 031111: Optical observations
  18. GRB 031111, optical observations
  19. SN 2003jd (SN/GRB?) -- X-ray Observations
  20. HETE Prompt GRB Spectral Analyses
  21. IPN triangulation of GRB031111 (=H2924): small error box
  22. XRF031109 (=H2919): A very long XRF localized by HETE
  23. IPN triangulation of GRB031108 (large error box)
  24. GRB031026: 1.2mm upper limit with MAMBO at the IRAM 30m
  25. GRB030929/SN2003jd association unlikely based on IPN localiztion
  26. Lulin optical follow-up observations of GRB031026
  27. SN 2003jd (SN/GRB?), Radio Observations
  28. SN 2003jd (SN/GRB?) - possible association with GRB 030929
  29. GRB 031026: Further Ic Observations
  30. GRB 031026 (=H2882): Evidence for High Redshift from Prompt
  31. Peculiar Type Ic SN 2003jd (SN/GRB?), optical spectrum
  32. IPN triangulation of GRB031024 (single error box)
  33. GRB031026 (=H2882): A Long, Hard Spectrum Burst Localized by HETE
  34. GRB 031026: Ic Observations
  35. GRB031026 : KISO optical follow-up observation
  36. GRB030329: radio observations at RT-22 (CrAO)
  37. HETE Prompt GRB Light Curves and Color-Color Diagrams
  38. Ongoing Bursting Activity from SGR 1806-20 detected with IBAS
  39. XRF 030824: additional observations at CFHT
  40. SGR1806-20 bursts on 031008. Helicon detection and small error box.
  41. SGR 1806-20 bursts with INTEGRAL and IBAS announcement on Soft Gamma-Ray Repeaters
  42. IPN detection of continued activity from SGR1806-20
  43. XRF 030723: Subaru Optical Observations
  44. A burst from SGR 1806-20 detected with IBAS
  45. XRF 030824: Early follow-up observation at Kiso observatory
  46. XRF 030824: observations at CFHT
  47. IPN triangulation of GRB030926 (short/hard; large error box)
  48. XRF 030723: Detection of the likely host galaxy
  49. XRF030824 (=H2821): An X-Ray Flash Localized by the HETE WXM
  50. XRF030823 (=H2818): An X-Ray Flash Localized by the HETE WXM and SXC
  51. IPN triangulation of GRB030922A (large error box)
  52. GRB030913: Subaru Optical Observations
  53. GRB 030913: ROTSE-3c Optical Observations
  54. GRB030913: OT's limit by MASTER
  55. GRB030913, candidate afterglow observations
  56. GRB 030913, optical candidate
  57. GRB030913: AAVSO optical observations
  58. GRB 030913, BOOTES observations
  59. GRB030913 (=H2849): Confirmation of the Flight Localization
  60. GRB030913: wide field imaging (7 sq.deg) of the error box by MASTER
  61. Magellan Observations of GRB030725 (=H2779)
  62. GRB030913 (=H2849): A GRB Possibly Localized by HETE
  63. GRB 030913: Optical limit at RIKEN
  64. XRF 020427: Gemini-South Spectroscopic Observations of the Host
  65. XRF030824: Optical observations
  66. IPN triangulation of GRB030903 (large error box)
  67. IBAS detection of bursts from SGR 1806-20
  68. Radio Observations of SGR1806-20
  69. IPN triangulation of GRB030827 (large error box)
  70. GRB 030823 observation at Ouda
  71. XRF030824: Second-epoch Palomar observations
  72. XRF030824: optical observations
  73. GRB030823: optical observations
  74. GRB030823: Palomar observations
  75. XRF030824: Palomar observations
  76. GRB 030824: Candidate Afterglow (or Variable/Flare Star?)
  77. GRB030823: optical observation at Tokyo Tech
  78. RAPTOR observations of GRB030823
  79. Lulin follow-up observations of GRB030823
  80. IPN triangulation of GRB030821 (=H2814; refined error box)
  81. GRB 030821(=H2814): A Faint, Long GRB Localized by the HETE WXM and the IPN
  82. IPN triangulation of GRB030814 (annulus)
  83. IPN detection of continued activity from SGR1806-20
  84. 030813 SGR event (Konus-Wind observation)
  85. GRB 030817 = H2808 TAROT optical observations
  86. SGR 1808-20 (=H2802): A Possible new SGR
  87. GRB 021206 Optical Observations
  88. IPN triangulation of GRB030806 (large burst; large error box)
  89. XRF030723(=H2777): Chandra Fading X-ray Afterglow Confirmed
  90. IPN/HETE summary of recent bursts from SGR1806-20
  91. XRF 030723: Detection of a rebrightening in the optical afterglow
  92. GRB030725: Optical observations
  93. XRF030723, BVRcIc field photometry update
  94. GRB021206 optical counterpart upper limit
  95. XRF030723: Re-analysis of ROTSE-III early images
  96. IPN triangulation of GRB030725 (=H2779; small error box)
  97. XRF030723 (=H2777): Second Epoch Magellan Observations
  98. GRB 030725: optical observations.
  99. GRB030725, optical transient observations
  100. XRF030723 Radio Observations

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