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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').

9654 results found.

  1. GRB030115: 1.2 mm upper limits with MAMBO @ IRAM 30m
  2. GRB 030115, simultaneous observations by BOOTES-1
  3. GRB030115: R-band counterpart of IR candidate
  4. GRB030115: Optical Observations, Swiss Telescope at La Silla (ESO, Chile)
  5. GRB030115 (=H2533): A Long GRB Localized by the HETE WXM and SXC
  6. GRB030115: R-band observations at Asiago
  7. GRB 030115: APO Optical Observations
  8. GRB 030115, no optical candidate
  9. IPN triangulation of GRB030102B (portion of annulus)
  10. GRB on 20030101 seen by SPI-ACS
  11. IPN triangulation of GRB021219
  12. GRB021219: a long GRB localized by INTEGRAL
  13. IPN detection of continued activity from SGR1806-20
  14. GRB 021201: Optical Observations
  15. GRB 021211: early break in light curve
  16. GRB021211: Optical observations in CrAO
  17. Chandra observation of the IPN error box of GRB021201 (short/hard)
  18. GRB 021211 Milagro GeV/TeV Observations
  19. GRB021211, OT at 108 s
  20. GRB021211 (=H2493): A Bright, Long GRB Localized by HETE-2 in Near-Real Time
  21. HETE 2493: Optical observations
  22. IPN triangulation of GRB021206 (exceptionally bright; annulus only)
  23. IPN detection of renewed activity from SGR1806-20
  24. GRB 021104, GRB 021112 and GRB 021113 - Milagro GeV/TeV Observations
  25. IPN detection of continued SGR1900+14 activity
  26. Improved IPN error box for GRB021125
  27. GRB021125 : A long GRB localized by INTEGRAL
  28. IPN confirmation of the reactivation of SGR1900+14
  29. IPN detection of possible reactivation of SGR1900+14
  30. IPN triangulation of GRB021119 (annulus)
  31. GRB021112: Optical Observations
  32. GRB021113 (=H2449): A Long GRB Localized by HETE
  33. GRB021112 (=H2448): A Long GRB Localized by HETE
  34. IPN triangulation of bursts from SGR1900+14, November 1-2, 2002
  35. SGR1900+14 activity, November 2-4, 2002
  36. Detection of activity from SGR 1900+14 with the RXTE/PCA
  37. GRB 021023: Curious K-band Source(s) Just Outside of IPN Localization
  38. GRB 021004: optical observations
  39. IPN triangulation of GRB021020 (smaller error box)
  40. GRB021021(=XRF 021021): An X-ray Flash Localized by HETE
  41. IPN triangulation of GRB021020
  42. GRB 021016, optical observations
  43. GRB 021004: VRI observations at TNG: possible break
  44. GRB 021008, optical observations
  45. GRB021016(=H2397): A Long GRB Localized by HETE
  46. GRB021004: NIR and Optical observations
  47. GRB 021004: Optical measurement at OHP
  48. GRB 021004: optical spectroscopy
  49. GRB021004: BVRc photometry
  50. GRB 021004: Optical Photometry at 2.5 Days
  51. GRB 021004 radio observation
  52. GRB 021004: Optical Observations
  53. GRB 021004: Optical Photometry at 1.5 Days
  54. GRB021004, Optical Observations
  55. GRB 021004, optical observations
  56. GRB 021004, SPM optical observations
  57. GRB 021004: steepening of the optical decay slope
  58. XRF020903, BVRI field photometry
  59. GRB 020903: Optical observations at RIKEN
  60. XRF 020903: Supernova
  61. IPN triangulation of GRB020926 (two large error boxes)
  62. GRB020924 (ecliptic latitude-only localization)
  63. IPN triangulation of GRB020923 (two error boxes)
  64. Improved IPN position for GRB020918 (two large error boxes)
  65. IPN triangulation of GRB020911 (2 large error boxes)
  66. IPN detection of a burst from SGR1900+14
  67. INTEGRAL GRBs added to GCN
  68. GRB020812: optical observation
  69. Second epoch K band imaging of GRB 020819
  70. GRB 020812: early time optical observation at Ouda Station
  71. GRB020813: Magellan BVRI Photometry
  72. GRB 020819 : OT candidate - confirmation of non variability
  73. K band observation of GRB 020819
  74. GRB020819(=H2275): A Long Burst Localized by the HETE WXM and SXC
  75. IPN triangulation of GRB020819 (HETE 2275)
  76. GRB020813: Fading X-ray Afterglow Observed with Chandra
  77. GRB020812: NIR observations
  78. GRB020812: optical observations
  79. GRB 020812 : optical afterglow candidate
  80. GRB020813, optical observations
  81. GRB 020812 optical observation
  82. GRB020812(=H2257): A Long Burst Localized by HETE in Near-Real Time
  83. GRB020801: Imaging of Suggested OT Counterpart at the Magellan
  84. GRB020801, optical afterglow candidate
  85. IPN triangulation of GRB020714
  86. GRB 020410: Discovery of Probable OT by HST
  87. Correction to IPN error box for GRB020706
  88. IPN triangulation of GRB020706
  89. GRB 020705: Optical observations
  90. GRB020625 (=H2081): A Long Burst Localized by HETE
  91. Gemini IR Detection of AXP 1E 2259+586 Post-Burst
  92. SGR-like X-ray Bursts from AXP 1E 2259+586: follow-up
  93. AXP 1E2259+586: quasi-simultaneous optical observation
  94. AXP 1E2259+586 optical observations
  95. SGR-like Bursts from the AXP 1E 2259+586
  96. GRB 020531, simultaneous optical observations
  97. GRB020531: Second epoch Chandra observations
  98. GRB020531: Observations with the Chandra X-ray Observatory
  99. GRB020531, optical observation
  100. IPN triangulation of the short, hard GRB020531 (=H2042)

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