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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').
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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.

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subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

20815 results found.

  1. GRB 241120A: GRBAlpha detection
  2. LIGO/Virgo/KAGRA S241125n: Identification of a GW compact binary merger candidate
  3. LIGO/Virgo/KAGRA S241122a: Identification of a GW compact binary merger candidate
  4. IPN triangulation of GRB 241117A
  5. GRB 241026A: VIRT Optical Upper Limit
  6. GRB 241025A: VIRT Optical Upper Limit
  7. GRB241120A: OHP/T193 optical observations
  8. EP241021a and EP241026b: Keck/LRIS spectroscopic observations
  9. EP-WXT trigger 01709018832: Lick/Kast spectroscopy with the 3 m Shane telescope
  10. GRB 241120A: Mondy and AbAO optical observations
  11. EP241119a: Optical upper limits with Kinder observations
  12. EP trigger ID 01709122294: the X-ray transient is likely a stellar flare event
  13. EP241119a: GIT optical upper limits
  14. EP241119a : J-band observations with WINTER
  15. EP241119a: EP detection of a fast X-ray transient
  16. GRB 241112B: Mephisto further optical observations
  17. GRB 241030A: J-band observations
  18. GRB 241115a: PRIME near-infrared upper limits
  19. GRB 241117A: Swift/BAT-GUANO localization skymap of a burst
  20. Fermi GRB 241118A: Global MASTER-Net observations report
  21. GRB 241117A: SVOM/GRM observation of a short burst with extended emission
  22. GRB 241115B: Swift/BAT-GUANO localization skymap of a long burst
  23. GRB 241115A: Swift-XRT afterglow detection
  24. LIGO/Virgo/KAGRA S241116cq: Identification of a GW compact binary merger candidate
  25. EP241115a/GRB 241115D: Optical upper limits with Kinder observations
  26. GRB 241115A: Mephisto upper limits
  27. GRB 241113B: Mephisto upper limits
  28. EP241115a/GRB 241115D: Swift/XRT follow-up observation
  29. GRB 241115D / EP 241115a: SVOM/GRM observation
  30. The EP-WXT trigger 01709120856 is likely a flaring star
  31. EP241113a: Swift XRT weak detection
  32. GRB 241115A: LCOGT Optical Upper Limits
  33. GRB 241115C: Swift/BAT-GUANO localization skymap of a burst
  34. LIGO/Virgo/KAGRA S241114bi: Updated Sky localization and EM Bright Classification
  35. EP241115a: EP detection of a fast X-ray transient
  36. GRB 241115A: Swift detection of a burst
  37. EP 241113a: LBT possible optical counterpart
  38. LIGO/Virgo/KAGRA S241114bi: Upper limits from Fermi-GBM Observations
  39. LIGO/Virgo/KAGRA S241114bi: Identification of a GW compact binary merger candidate
  40. GRB 241113A: PRIME near-infrared upper limits
  41. GRB 241113B: J-band upper limit from WINTER
  42. GRB 241113A: J-band observations with WINTER
  43. EP241113a : J-band observations with WINTER
  44. GRB 241030A: LCO optical observation
  45. GRB 241113B: Swift-XRT observations
  46. GRB 241113A: 1.6m Mephisto and 50cm array optical upper limits
  47. EP241113b/GRB 241113B: EP detection of GRB 241113B
  48. LIGO/Virgo/KAGRA S241114y: Identification of a GW compact binary merger candidate
  49. GRB 241113A: Swift-XRT refined Analysis
  50. GRB 241113A: Swift/UVOT Detection
  51. GRB 241113A: REM detection of the optical/NIR afterglow
  52. Konus-Wind detection of GRB 241107A (short/hard)
  53. LIGO/Virgo/KAGRA S241113p: Identification of a GW compact binary merger candidate
  54. GRB 241113A: LCO optical observations
  55. GRB 241112B: GMG Optical Upper Limit
  56. GRB 241113A: Enhanced Swift-XRT position
  57. GRB241113A: LCOGT (40-cm) optical counterpart detection
  58. GRB 241113A: Swift detection of a burst with an optical counterpart
  59. SVOM/GRM detection of a short burst from SGR 1E1841-045
  60. GRB 241105A: ATCA Radio Upper Limits
  61. GRB 241112B: AbAO optical upper limit
  62. GRB 241107A: GROWTH-India telescope optical upper limit
  63. GRB 241112B: Optical afterglow detection confirmation in revisiting the Mephisto data
  64. GRB 241112B: Swift-XRT afterglow detection
  65. GRB 241112B: LCO optical detection of the SVOM/VT candidate
  66. GRB 241107A: Swift/BAT candidate arcminute localization of a short burst
  67. GRB 241112B: Mephisto optical upper limits
  68. GRB 241112B: GOTO optical upper limits
  69. GRB 241107A: INTEGRAL IBIS localization
  70. LIGO/Virgo/KAGRA S241109bn: ATLAS observations and discovery of the potential counterpart AT2024aawt
  71. LIGO/Virgo/KAGRA S241111bn: Identification of a GW compact binary merger candidate
  72. IPN triangulation of GRB 241107A (short/hard)
  73. GRB 241018A: cubesat Avion detection
  74. GRB 241030B: TESS detection of optical counterpart
  75. LIGO/Virgo/KAGRA S241110bk: 1 counterpart neutrino candidate event from an IceCube neutrino search
  76. LIGO/Virgo/KAGRA S241110br: Identification of a GW compact binary merger candidate
  77. LIGO/Virgo/KAGRA S241109bn: Upper limits from EP-WXT observations
  78. LIGO/Virgo/KAGRA S241109bn: Coverage and upper limits from MAXI/GSC observations
  79. EP241109a: KAIT photometry and 3 m Shane spectroscopy from Lick observatory
  80. LIGO/Virgo/KAGRA S241109bn: Updated Sky localization and EM Bright Classification
  81. EP241107a: AbAO optical upper limit
  82. LIGO/Virgo/KAGRA S241109bn: Upper limits from Fermi-GBM Observations
  83. GRB 241108A: Further COLIBRÍ Upper Limits on the Optical Counterpart
  84. LIGO/Virgo/KAGRA S241109bn: Identification of a GW compact binary merger candidate
  85. GRB 241108A: Swift-XRT observations
  86. LIGO/Virgo/KAGRA S241109p: Identification of a GW compact binary merger candidate
  87. EP241107a: KAIT optical observations
  88. GRB 241030A: TESS observations
  89. GRB 241108A: COLIBRÍ Upper Limits on the Optical Counterpart
  90. EP241107a: Kinder optical follow-up observations
  91. GRB 241025A: radio detection with the VLA
  92. EP241107a: AKO Optical Afterglow Follow-Up Observations
  93. EP241107a: Gemini-South spectroscopic confirmation (z = 0.456)
  94. GRB 241105A: SVOM/GRM observation
  95. EP241107a: OHP/T193 photometric and spectroscopic observations
  96. GRB 241105a: PRIME near-infrared upper limits
  97. GRB 241105A: ePESSTO+ NTT optical afterglow detection
  98. EP241107a: GIT optical observations
  99. EP241107a: SVOM/C-GFT optical observations
  100. EP241107a: AKO Optical Afterglow Detection

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