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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"

27558 results found.

  1. GRB 021203: A Normal GRB viewed far off axis?
  2. GRB 031203: Variable Radio Source
  3. GRB 031203: Optical/IR Astrometry
  4. GRB031203: K' Photometry of the likely GRB host
  5. GRB 031203: Radio detection
  6. GRB 031203: IR NTTobservations do not confirm REM detection
  7. GRB 031203: z ~ 10 or Fragmented Dust in the Circumburst Environment?
  8. IPN detection of activity from SGR1806-20
  9. GRB 031111: Optical observations
  10. GRB 031026 (=H2882): Evidence for High Redshift from Prompt
  11. GRB030329: radio observations at RT-22 (CrAO)
  12. SGR1806-20 bursts on 031008. Helicon detection and small error box.
  13. IPN detection of continued activity from SGR1806-20
  14. XRF 030723: Subaru Optical Observations
  15. XRF 030723: Detection of the likely host galaxy
  16. GRB030913: Subaru Optical Observations
  17. GRB030913, candidate afterglow observations
  18. GRB 030913, optical candidate
  19. GRB030913: AAVSO optical observations
  20. GRB030913 (=H2849): Confirmation of the Flight Localization
  21. Magellan Observations of GRB030725 (=H2779)
  22. GRB030913 (=H2849): A GRB Possibly Localized by HETE
  23. XRF 020427: Gemini-South Spectroscopic Observations of the Host
  24. IBAS detection of bursts from SGR 1806-20
  25. GRB 030824: Candidate Afterglow (or Variable/Flare Star?)
  26. IPN detection of continued activity from SGR1806-20
  27. GRB 021206 Optical Observations
  28. XRF030723(=H2777): Chandra Fading X-ray Afterglow Confirmed
  29. XRF 030723: Detection of a rebrightening in the optical afterglow
  30. GRB030725: Optical observations
  31. XRF030723, BVRcIc field photometry update
  32. XRF030723: Re-analysis of ROTSE-III early images
  33. GRB 030725: optical observations.
  34. GRB030725, optical transient observations
  35. XRF030723 Radio Observations
  36. XRF030723(=H2777): Chandra Observations
  37. XRF 030723: VLT spectra
  38. GRB030725, possible optical transient
  39. XRF030723: Palomar observations and proposed counterpart
  40. XRF 030723, optical observations
  41. Konus-Wind detection of the bursts from SGR1806-20 region
  42. GRBlog: Compilation of all GCN Circ. data
  43. IPN detection of renewed activity from SGR1806-20
  44. IPN triangulation of GRB030711 (annulus, =SGR0525-66?)
  45. GRB030329: second XMM-Newton observation
  46. GRB030418: R optical observations
  47. HETE detection of burst from SGR1806-20
  48. GRB 021206, Radio afterglow candidate
  49. GRB030528(=H2724): X-ray Afterglow Identified in Second Epoch
  50. GRB 030528: Infrared Observations and the Proposed IR Counterpart
  51. GRB 030528: Optical Observations
  52. GRB 030528: tentative NIR counterpart
  53. GRB030329, further radio observations at GMRT
  54. GRB 030519B: optical observations.
  55. GRB 030329: optical observations
  56. GRB 030329: Correction to GCN 2254
  57. GRB 030329: Optical Observations
  58. GRB 021004: HST observations
  59. GRB030324: Further Observations of the Candidate Optical Afterglow
  60. GRB 030418: Second Epoch Optical Observations with Magellan
  61. GRB 030329: Optical limit (contemporaneous imaging)
  62. GRB030329: RTT150 optical observations
  63. GRB 030329: Optical limit (contemporaneous photography)
  64. GRB 030429: Redshift of neighbor galaxy
  65. GRB030429: RTT150 optical observations, a possible host galaxy
  66. GRB030329: RTT150 optical observations and upper limit for a host
  67. GRB 030329: all-sky CCD images by K. Shiokawa immediately after the burst
  68. GRB030329: RTT150 optical observations and upper limit for a host
  69. GRB 030429: redshift from VLT spectroscopy
  70. GRB 030429: IR photometry with IRSF/SIRIUS
  71. GRB 030329 Optical Observations
  72. GRB030501: TAROT candidate afterglow present in archival images
  73. GRB 030429: confirmation of afterglow candidate
  74. GRB030501 localized by INTEGRAL
  75. GRB 030329 Oprical observations in Rozhen observatory
  76. GRB 030324: Radio Observations
  77. GRB030329 observed as a sudden ionospheric disturbance (SID)
  78. SNeIa AS THE POSSIBLE PROGENITORS OF SHORT-DURATION GRBs.
  79. GRB 030329: Spectral Evolution of SN 2003dh
  80. Optical Observations of GRB 030418 with Magellan
  81. GRB 030329: optical spectropolarimetry at VLT
  82. GRB 030329: wide-field photograph by R. Tamura 1 hr after the burst
  83. GRB030418: Kiso near infrared observations
  84. GRB 030418: Optical afterglow
  85. GRB 030418: Finder for afterglow candidate
  86. GRB 030418: Optical afterglow candidate
  87. GRB030329, UBVRI polarimetry, R-polarization
  88. GRB 030329: SARA Optical Observations
  89. OT GRB 030329: early spectrum
  90. GRB030329: VR Photometry at TNG
  91. GRB030324: Candidate Optical Afterglow (Erratum)
  92. GRB030324: Candidate Optical Afterglow
  93. GRB 030329 Rc observations
  94. Superluminal motion in GRB 030329 (Correction)
  95. Superluminal motion in GRB 030329
  96. GRB 030329 and SN 2003dh
  97. GRB 030329 VLBA Observations
  98. GRB 030329: BVRI photometry at Asiago
  99. GRB 030329: Supernova Confirmed
  100. GRB030329: RTT150 optical observations

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