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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"

41622 results found.

  1. GRB 030823 observation at Ouda
  2. XRF030824: Second-epoch Palomar observations
  3. XRF030824: optical observations
  4. GRB030823: optical observations
  5. GRB030823: Palomar observations
  6. XRF030824: Palomar observations
  7. GRB 030824: Candidate Afterglow (or Variable/Flare Star?)
  8. GRB030823: optical observation at Tokyo Tech
  9. RAPTOR observations of GRB030823
  10. Lulin follow-up observations of GRB030823
  11. IPN triangulation of GRB030821 (=H2814; refined error box)
  12. GRB 030821(=H2814): A Faint, Long GRB Localized by the HETE WXM and the IPN
  13. IPN detection of continued activity from SGR1806-20
  14. GRB 030817 = H2808 TAROT optical observations
  15. SGR 1808-20 (=H2802): A Possible new SGR
  16. GRB 021206 Optical Observations
  17. IPN triangulation of GRB030806 (large burst; large error box)
  18. XRF030723(=H2777): Chandra Fading X-ray Afterglow Confirmed
  19. IPN/HETE summary of recent bursts from SGR1806-20
  20. XRF 030723: Detection of a rebrightening in the optical afterglow
  21. GRB030725: Optical observations
  22. XRF030723, BVRcIc field photometry update
  23. GRB021206 optical counterpart upper limit
  24. XRF030723: Re-analysis of ROTSE-III early images
  25. IPN triangulation of GRB030725 (=H2779; small error box)
  26. XRF030723 (=H2777): Second Epoch Magellan Observations
  27. GRB 030725: optical observations.
  28. GRB030725, optical transient observations
  29. XRF030723 Radio Observations
  30. XRF 030723: confirmation of fading optical counterpart
  31. XRF030723(=H2777): Chandra Observations
  32. XRF 030723: VLT spectra
  33. Magellan Observations of XRF030723 (=H2777)
  34. GRB030723: Upper limits from historical observations
  35. GRB030725, possible optical transient
  36. XRF030723: Palomar observations and proposed counterpart
  37. XRF030723: optical observations
  38. XRF030723 (= H2777): Chandra Observations Scheduled
  39. XRF030723, ROTSE-III Early Observations
  40. XRF030723, BVRcIc field photometry
  41. XRF 030723, optical observations
  42. XRF030723, optical observations
  43. XRF 030723, optical observations
  44. XRF030723 (=H2777): An X-ray Flash Localized by the HETE WXM and
  45. GRB030723, optical observations
  46. Konus-Wind detection of the bursts from SGR1806-20 region
  47. SGR 1806-20, submm observations
  48. H2768, H2770, and H2771: Three Bursts from SGR1806-20
  49. RXTE PCA Observations of SGR1806-20 Region
  50. GRB030329: Subaru Optical Spectroscopy
  51. Triangulation of GRB030715 (single large error box)
  52. Triangulation of GRB030714 (single large error box)
  53. IPN triangulation of GRB030714 (two large error boxes)
  54. IPN triangulation of GRB030715 (two large error boxes)
  55. GRB030329: RTT150 optical observations
  56. GRBlog: Compilation of all GCN Circ. data
  57. IPN detection of renewed activity from SGR1806-20
  58. GRB030329, optical observation in May
  59. IPN triangulation of GRB030626 (two large error boxes)
  60. GRB030329: second XMM-Newton observation
  61. GRB030418: R optical observations
  62. GRB030329 -- RATAN-600 data in April-May
  63. Final IPN error ellipse for GRB021206 (the polarized GRB)
  64. GRB 021206, Radio afterglow candidate
  65. GRB030528(=H2724): X-ray Afterglow Identified in Second Epoch
  66. IPN triangulation of GRB030607 (annulus)
  67. IPN triangulation of GRB030606 (two alternate error boxes)
  68. GRB030329, SPM optical observations (Correction of GCN2075 R band)
  69. GRB 030528: Infrared Observations and the Proposed IR Counterpart
  70. GRB 030528: Optical Observations
  71. GRB 030528: tentative NIR counterpart
  72. GRB 030528, radio observations
  73. GRB030528(=H2724): Observations with the Chandra X-ray Observatory
  74. GRB030329, further radio observations at GMRT
  75. GRB030528, BVRI field photometry
  76. GRB030329, SPM optical observations
  77. GRB030528: Chandra TOO Planned
  78. GRB 030519B: optical observations.
  79. MASTER: optical observation GRB030601
  80. GRB030528(=H2724): Revised SXC Localization
  81. GRB 030329: optical observations
  82. GRB 030329/SN 2003dh: Jitter Episode
  83. GRB 030528, Teramo optical observation
  84. GRB 030528 Bisei optical observation
  85. GRB 030329: Correction to GCN 2254
  86. GRB 030329: Optical Observations
  87. GRB 030528: Optical observations at RIKEN
  88. GRB 030528 (=H2724) Kyoto optical observation
  89. GRB 030416: Optical Observations
  90. GRB 030329: optical photometry at Belesta observatory (France)
  91. GRB030329, Optical observations
  92. GRB 030329/SN 2003dh: Possible increase in brightness
  93. GRB 030329: HST ACS Observations of the Host
  94. GRB 030329 Optical Observations
  95. GRB030329: XMM-Newton observation
  96. GRB 021004: HST observations
  97. GRB030324: Further Observations of the Candidate Optical Afterglow
  98. GRB030519B (=H2716): Peak Fluxes, Fluences, and Energy Spectrum
  99. GRB 030418: Second Epoch Optical Observations with Magellan
  100. IPN triangulation of GRB030518B (annulus)

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