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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"

32508 results found.

  1. GRB 040319 (=H3128): An X-Ray-Rich GRB Localized by the HETE-2 WXM and SXC
  2. GRB 040323, a dark GRB ?
  3. GRB040223: Deep NIR NTT data re-analysis
  4. GRB 040223: XMM-Newton results
  5. GRB040223, improved XMM position
  6. GRB 031203: spectoscopic evidence for a 1998bw-like SN
  7. GRB 031203, possible supernova
  8. IBAS results on a burst from SGR1806-20
  9. GRB 040228 Optical observations
  10. IPN triangulation of GRB040228 (H3066, H3067)
  11. GRB 040228 (=H3066?,=H3067?): A Long GRB Localized by the HETE-2 WXM
  12. GRB 040223: Deep NIR NTT observations
  13. GRB 040223 : Optical observation (non-detection)
  14. XMM-Newton Images of GRB 040223
  15. GRB 040223, VLA observations
  16. GRB 040223: REM IJK Observations
  17. GRB 040223 XMM-Newton observation ...
  18. GRB 031203 XMM-Newton observation
  19. GRB031111, optical observations
  20. GRB031220: 2nd Chandra observation and X-ray afterglow candidate
  21. GRB031203: Chandra Observations
  22. GRB040106, follow-up radio observations
  23. GRB040106: refined X-ray transient position
  24. Follow-up on IBAS GRB Alert 1379
  25. SN 2003dh/GRB030329 late-time optical spectroscopy
  26. GRB040106, Radio Observations
  27. GRB040106, likely optical afterglow
  28. GRB040106: Second Epoch Optical Observations
  29. GRB 031220: Optical observations of Chandra X-ray sources
  30. XMM-Newton Images of GRB 040106
  31. GRB040106: optical observations with REM+ROSS
  32. GRB031220: observation at Univercity of Miyazaki
  33. GRB 040106: Optical observations
  34. XMM-Newton observation of GRB040106
  35. GRB031220(=H2976): TNG R-band Observation of the Chandra X-ray Sources
  36. GRB031220(=H2976): Observation with the Chandra X-ray Observatory
  37. GRB 031203 I-band monitoring
  38. IPN triangulation of GRB031214 (short/hard; very intense; small error box)
  39. GRB 2974 follow-up observations
  40. GRB031203, improved XMM position
  41. GRB 031203: SMARTS optical monitoring
  42. GRB 021203: A Normal GRB viewed far off axis?
  43. GRB 031203: Variable Radio Source
  44. GRB 031203: Magellan spectrum of possible GRB host
  45. GRB 031203: Optical/IR Astrometry
  46. GRB031203 K prime photometry: correction to galaxy coordinates
  47. GRB031203: ROSAT upper limits suggest XMM-S1 source as the transient
  48. XMM-Newton Observation of GRB031203
  49. GRB031203: K' Photometry of the likely GRB host
  50. XMM-Newton Observation of GRB031203
  51. GRB 031203: Radio detection
  52. GRB 031203: Further reports on December 4 observations
  53. GRB 031203: IR NTTobservations do not confirm REM detection
  54. GRB 031203: z ~ 10 or Fragmented Dust in the Circumburst Environment?
  55. GRB 031203: Apparent Spectral Break
  56. GRB031203: Planned XMM-Newton observation II
  57. GRB 031203: IR REM Observations
  58. GRB031203: Optical Observations
  59. GRB 031203 XMM-Newton observation
  60. GRB 031203: Optical/IR SMARTS Observations
  61. GRB031203: Planned XMM-Newton observation
  62. GRB031111A, prompt optical observations
  63. GRB 031111, Radio observations
  64. GRB 031111: Optical observations
  65. GRB 031111, optical observations
  66. SN 2003jd (SN/GRB?) -- X-ray Observations
  67. IPN triangulation of GRB031111 (=H2924): small error box
  68. XRF031109 (=H2919): A very long XRF localized by HETE
  69. GRB031026: 1.2mm upper limit with MAMBO at the IRAM 30m
  70. GRB030929/SN2003jd association unlikely based on IPN localiztion
  71. Lulin optical follow-up observations of GRB031026
  72. SN 2003jd (SN/GRB?), Radio Observations
  73. SN 2003jd (SN/GRB?) - possible association with GRB 030929
  74. GRB 031026: Further Ic Observations
  75. GRB 031026 (=H2882): Evidence for High Redshift from Prompt
  76. Peculiar Type Ic SN 2003jd (SN/GRB?), optical spectrum
  77. IPN triangulation of GRB031024 (single error box)
  78. GRB031026 (=H2882): A Long, Hard Spectrum Burst Localized by HETE
  79. XRF 030824: additional observations at CFHT
  80. SGR1806-20 bursts on 031008. Helicon detection and small error box.
  81. SGR 1806-20 bursts with INTEGRAL and IBAS announcement on Soft Gamma-Ray Repeaters
  82. XRF 030723: Subaru Optical Observations
  83. XRF 030824: Early follow-up observation at Kiso observatory
  84. XRF 030723: Detection of the likely host galaxy
  85. XRF030824 (=H2821): An X-Ray Flash Localized by the HETE WXM
  86. XRF030823 (=H2818): An X-Ray Flash Localized by the HETE WXM and SXC
  87. IPN triangulation of GRB030922A (large error box)
  88. IPN triangulation of GRB030921 (large error box)
  89. GRB030913: Subaru Optical Observations
  90. GRB 030913: ROTSE-3c Optical Observations
  91. GRB030913: OT's limit by MASTER
  92. GRB030913, candidate afterglow observations
  93. GRB030913: AAVSO optical observations
  94. GRB030913 (=H2849): Confirmation of the Flight Localization
  95. GRB030913 (=H2849): TAROT Observations
  96. Magellan Observations of GRB030725 (=H2779)
  97. GRB030913 (=H2849): A GRB Possibly Localized by HETE
  98. IBAS detection of bursts from SGR 1806-20
  99. Radio Observations of SGR1806-20
  100. GRB 030824: Candidate Follow-Up

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