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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"

32489 results found.

  1. XRF030723: Re-analysis of ROTSE-III early images
  2. IPN triangulation of GRB030725 (=H2779; small error box)
  3. XRF030723 (=H2777): Second Epoch Magellan Observations
  4. GRB 030725: optical observations.
  5. GRB030725, optical transient observations
  6. XRF030723 Radio Observations
  7. XRF 030723: confirmation of fading optical counterpart
  8. XRF030723(=H2777): Chandra Observations
  9. XRF 030723: VLT spectra
  10. Magellan Observations of XRF030723 (=H2777)
  11. GRB030723: Upper limits from historical observations
  12. GRB030725, possible optical transient
  13. XRF030723: Palomar observations and proposed counterpart
  14. GRB030725 (=H2779): A Bright GRB Localized by HETE
  15. XRF030723: optical observations
  16. XRF030723 (= H2777): Chandra Observations Scheduled
  17. XRF030723, BVRcIc field photometry
  18. XRF030723, optical observations
  19. XRF030723 (=H2777): An X-ray Flash Localized by the HETE WXM and
  20. Konus-Wind detection of the bursts from SGR1806-20 region
  21. SGR 1806-20, submm observations
  22. RXTE PCA Observations of SGR1806-20 Region
  23. GRB030329: Subaru Optical Spectroscopy
  24. Triangulation of GRB030715 (single large error box)
  25. Triangulation of GRB030714 (single large error box)
  26. GRB030329: RTT150 optical observations
  27. GRBlog: Compilation of all GCN Circ. data
  28. GRB030706 triangulation (single large error box)
  29. GRB030329, optical observation in May
  30. IPN triangulation of GRB030626 (single large error box)
  31. GRB030418: R optical observations
  32. Final IPN error ellipse for GRB021206 (the polarized GRB)
  33. GRB 021206, Radio afterglow candidate
  34. GRB030528(=H2724): X-ray Afterglow Identified in Second Epoch
  35. GRB 030528: Infrared Observations and the Proposed IR Counterpart
  36. GRB 030528: Optical Observations
  37. GRB 030528: tentative NIR counterpart
  38. GRB 030528, radio observations
  39. GRB030329, further radio observations at GMRT
  40. GRB030528, BVRI field photometry
  41. GRB030329, SPM optical observations
  42. GRB030528: Chandra TOO Planned
  43. GRB 030519B: optical observations.
  44. GRB 030329: optical observations
  45. GRB 030329/SN 2003dh: Jitter Episode
  46. GRB 030528, Teramo optical observation
  47. GRB 030528 Bisei optical observation
  48. GRB030528 (H2724): A long GRB localized by HETE
  49. GRB 030329: Correction to GCN 2254
  50. GRB 030329: Optical Observations
  51. GRB 030416: Optical Observations
  52. GRB030329, Optical observations
  53. GRB 030329/SN 2003dh: Possible increase in brightness
  54. GRB 030329: HST ACS Observations of the Host
  55. GRB 030329 Optical Observations
  56. GRB030329: XMM-Newton observation
  57. GRB030324: Further Observations of the Candidate Optical Afterglow
  58. GRB030519B (=H2716): Peak Fluxes, Fluences, and Energy Spectrum
  59. IPN triangulation of GRB030519B=H2716 (small error box)
  60. GRB 030418: Second Epoch Optical Observations with Magellan
  61. GRB030519B (=H2716): A Long, Bright GRB Localized by the HETE WXM
  62. HETE GRB030329, correction to Rc Observations in Loiano
  63. GRB 030329: Optical limit (contemporaneous imaging)
  64. GRB 030501: final TAROT limits
  65. IPN triangulation of GRB030509 (small errror box)
  66. IPN triangulation of GRB030509 - correction
  67. GRB030329: RTT150 optical observations
  68. GRB030329, BVRI photometry
  69. GRB030429, refiend optical brightness
  70. GRB 030329: Optical limit (contemporaneous photography)
  71. GRB030418, BVRcIc field photometry
  72. GRB 030429: Redshift of neighbor galaxy
  73. GRB030429, BVRcIc field photometry
  74. GRB030429: RTT150 optical obs., correction to GCN 2208
  75. GRB 030329: High-Resolution Spectroscopy of the Host
  76. GRB030429 (=H2695): A Long GRB Localized by the HETE WXM and SXC
  77. GRB030418 (=H2686): A Long, X-Ray-Rich GRB Localized by the HETE WXM
  78. XRF030416 (=U10897): An X-Ray Flash Localized by the HETE WXM
  79. GRB030429: RTT150 optical observations, a possible host galaxy
  80. GRB030329: RTT150 optical observations and upper limit for a host
  81. GRB030501, optical observation
  82. GRB030501 observation report
  83. GRB030501 triangulation (correction to GCN 2194)
  84. GRB030329: RTT150 optical observations and upper limit for a host
  85. GRB 030429: Radio Observations
  86. GRB 030429: redshift from VLT spectroscopy
  87. GRB 030429: IR photometry with IRSF/SIRIUS
  88. GRB030501B triangulation (single error box)
  89. GRB 030329 Optical Observations
  90. GRB030328, optical observation
  91. GRB 030329, BVRI photometry
  92. GRB030429: Optical Observations
  93. GRB030501: TAROT candidate afterglow present in archival images
  94. GRB 030501: TAROT possible candidate counterpart
  95. IPN triangulation of GRB030501 (IBIS event; annulus)
  96. GRB 030429: confirmation of afterglow candidate
  97. GRB030425: CrAO optical observation
  98. GRB 030329 Oprical observations in Rozhen observatory
  99. GRB 030324: Radio Observations
  100. GRB030329 observed as a sudden ionospheric disturbance (SID)

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