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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"

44630 results found.

  1. XRF 030723: confirmation of fading optical counterpart
  2. XRF030723(=H2777): Chandra Observations
  3. XRF 030723: VLT spectra
  4. Magellan Observations of XRF030723 (=H2777)
  5. GRB030723: Upper limits from historical observations
  6. GRB030725, possible optical transient
  7. XRF030723: Palomar observations and proposed counterpart
  8. GRB030725 (=H2779): A Bright GRB Localized by HETE
  9. XRF030723: optical observations
  10. XRF030723 (= H2777): Chandra Observations Scheduled
  11. XRF030723, BVRcIc field photometry correction
  12. XRF030723, ROTSE-III Early Observations
  13. XRF030723, BVRcIc field photometry
  14. XRF 030723, optical observations
  15. XRF030723, optical observations
  16. XRF 030723, optical observations
  17. XRF030723 (=H2777): An X-ray Flash Localized by the HETE WXM and
  18. GRB030723, optical observations
  19. Konus-Wind detection of the bursts from SGR1806-20 region
  20. IBAS GRB Alerts 969 970
  21. SGR 1806-20, submm observations
  22. H2768, H2770, and H2771: Three Bursts from SGR1806-20
  23. IPN triangulation of GRB030717 (annulus)
  24. RXTE PCA Observations of SGR1806-20 Region
  25. GRB030329: Subaru Optical Spectroscopy
  26. Triangulation of GRB030715 (single large error box)
  27. Triangulation of GRB030714 (single large error box)
  28. 030716 NOT a GRB
  29. IPN triangulation of GRB030714 (two large error boxes)
  30. IPN triangulation of GRB030715 (two large error boxes)
  31. GRB030329: RTT150 optical observations
  32. GRBlog: Compilation of all GCN Circ. data
  33. IPN detection of renewed activity from SGR1806-20
  34. IPN triangulation of GRB030711 (annulus, =SGR0525-66?)
  35. IPN triangulation of GRB030710 (annulus)
  36. IPN triangulation of GRB030709 (annulus)
  37. GRB030706 triangulation (single large error box)
  38. IPN triangulation of GRB030706 (annulus)
  39. IPN triangulation of GRB030629 (annulus)
  40. GRB030629 triangulation (Konus-Wind -- Helicon annulus)
  41. 030629 NOT a real GRB
  42. GRB030329, optical observation in May
  43. IPN triangulation of GRB030626 (single large error box)
  44. IPN triangulation of GRB030626 (two large error boxes)
  45. GRB030329: second XMM-Newton observation
  46. GRB030418: R optical observations
  47. HETE detection of burst from SGR1806-20
  48. GRB030329 -- RATAN-600 data in April-May
  49. Final IPN error ellipse for GRB021206 (the polarized GRB)
  50. GRB 021206, Radio afterglow candidate
  51. GRB030528(=H2724): X-ray Afterglow Identified in Second Epoch
  52. IPN triangulation of GRB030607 (annulus)
  53. IPN triangulation of GRB030606 (two alternate error boxes)
  54. GRB030329, SPM optical observations (Correction of GCN2075 R band)
  55. GRB 030528: Infrared Observations and the Proposed IR Counterpart
  56. IPN triangulation of GRB030605B (annulus)
  57. GRB 030528: Optical Observations
  58. IPN triangulation of GRB030605 (annulus)
  59. GRB 030528: tentative NIR counterpart
  60. GRB 030528, radio observations
  61. GRB030528(=H2724): Observations with the Chandra X-ray Observatory
  62. GRB030329, further radio observations at GMRT
  63. GRB030528, BVRI field photometry
  64. IPN triangulation of GRB030601 (annulus)
  65. GRB030329, SPM optical observations
  66. GRB030528: Chandra TOO Planned
  67. GRB 030519B: optical observations.
  68. MASTER: optical observation GRB030601
  69. GRB030528(=H2724): Revised SXC Localization
  70. GRB 030329: optical observations
  71. GRB 030329/SN 2003dh: Jitter Episode
  72. GRB 030528, Teramo optical observation
  73. GRB 030528 Bisei optical observation
  74. GRB030528 (H2724): A long GRB localized by HETE
  75. GRB 030329: Correction to GCN 2254
  76. GRB 030329: Optical Observations
  77. GRB 030528: Optical observations at RIKEN
  78. GRB 030528 (=H2724) Kyoto optical observation
  79. IPN triangulation of GRB030523B (annulus)
  80. GRB 030416: Optical Observations
  81. GRB 030329: Planned XMM-Newton Observation
  82. IPN triangulation of GRB030523 (annulus)
  83. GRB 030329: optical photometry at various french observatories
  84. GRB 030329: optical photometry at Belesta observatory (France)
  85. GRB030329, Optical observations
  86. GRB 030329/SN 2003dh: Possible increase in brightness
  87. GRB 030329: HST ACS Observations of the Host
  88. GRB 030329 Optical Observations
  89. GRB030329: XMM-Newton observation
  90. GRB 021004: HST observations
  91. GRB030324: Further Observations of the Candidate Optical Afterglow
  92. GRB030519B (=H2716): Peak Fluxes, Fluences, and Energy Spectrum
  93. IPN triangulation of GRB030519B=H2716 (small error box)
  94. GRB 030418: Second Epoch Optical Observations with Magellan
  95. GRB030519B (=H2716): A Long, Bright GRB Localized by the HETE WXM
  96. IPN triangulation of GRB030519 (annulus)
  97. IPN triangulation of GRB030518C (annulus)
  98. IPN triangulation of GRB030518B (annulus)
  99. IPN triangulation of GRB030518A (annulus)
  100. IPN triangulation of GRB030514 (annulus)

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